A1

PERINEURAL PREGABALIN INFUSION IN A RAT NEUROPATHIC PAIN MODEL M. Buys, C. Alphonso Anesthesiology, San Antonio Military Medical Center, Lackland, TX, USA Background:

Peripheral neuropathy is a painful condition that has few medications available for its treatment. Pregabalin (Lyrica®) was FDA approved in 1999 for the treatment of epilepsy. Since then it has also been used in the treatment of peripheral neuropathy in diabetes and herpes zoster and in the treatment of fibromyalgia. Pregabalin is an orally administered medication that is believed to exert its effect through interaction with the α2δ1 calcium channel subunits in the CNS. Recent data also suggest that pregabalin's antinociceptive effects may be mediated by inhibiting the anterograde trafficking of the α2δ1 calcium channel subunit in the peripheral nervous system.

Hypothesis/Objective: We hypothesize that the perineural application of a solution of pregabalin will improve neuropathic pain and be superior to systemic pregabalin in a rat sciatic nerve injury model by inhibiting anterograde trafficking of α2δ1 calcium channel subunits. Material and methods:

Forty male Sprague Dawley rats were randomized into four study groups: Sciatic nerve crush injury with perineural pregabalin infusion (T), sciatic crush injury with perineural saline infusion (SA), nerve crush injury with subcutaneous pregabalin (SC), and a sham group without nerve injury (C). Drug or vehicle was continuously infused via a mini-osmotic pump with either a 1% solution of Pregabalin (Groups T and SC) or Saline (Groups SA, and C) for a period of 7 days. All animals underwent nociceptive behavioral testing using guarding, incapacitance meter, von Frey, and heat lamp tests on post-operative days 1, 2, 4, and 7. On day 7, the sciatic nerves were harvested for either histologic or immunohistochemical testing. Results:

Behavioral Tests: Group T had significantly better guarding scores than groups SC or SA at all post-operative time points (p< 0.01) and had significantly better incapacitance scores than groups SC and SA on post-operative days 1,2, and 4 (p< 0.01). Group SC has significantly better guarding and incapacitance scores than group SA at all post-operative time points (p< 0.01). There was no significant difference between any group at any time point with von Frey or heat lamp testing.

Pathology: All perineural catheter tips were in place at end of study and drug delivery confirmed. Nerve crush injury produced significant axonal degeneration and necrosis with proliferation of Schwann cells and influx of macrophages in all specimens. There was no difference in severity between crush specimens. All injured specimens appeared to be at the same stage of injury progression. All injured nerves appeared normal a short distance proximal to the injury site. Contralateral nerves appeared normal.

Immunohistochemistry: In progress. Conclusions: Perineural pregabalin treatment is superior to systemic pregabalin in reducing pain behavior in a sciatic nerve crush injury model demonstrating that the drug likely has a peripheral mechanism of action in addition to central mechanisms. Perineural pregabalin does not appear to inhibit the natural injury/repair course during the first 7 days after crush injury. Perineural application of pregabalin may be promising as a novel approach for the treatment of neuropathic pain.

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[018_Figure3] A2

THE EFFECT OF A PERI-ARTICULAR INJECTION MIXTURE OF ROPIVACAINE, EPINEPHRINE, KETOROLAC, AND MORPHINE IN ADDITION TO AN ESTABLISHED MULTIMODAL PERIOPERATIVE ANALGESIC REGIMEN FOR TOTAL KNEE ARTHROPLASTY, ON POSTOPERATIVE PAIN AND REHABILITATION J. Mollov, J. Wei, V. Rasquinha, D. Dimaculangan Anesthesiology, Orthopedic Surgery and Rehabilitation Medicine, SUNY Downstate, Anesthesiology, Brooklyn, New York, NY, USA Introduction

Acute pain after total knee arthroplasty (TKA) surgery is often severe and could last for 2 to 3 days post-operatively. Effective analgesia after TKA is very important because it can facilitate early rehabilitation, improve patient satisfaction, reduce hospital stay and result in decreased healthcare costs. In order to limit parenteral opioids, which are associated with inadequate pain relief, generalized sedation, and adverse side effects such as nausea, vomiting, ileus, pruritus, and respiratory depression, providers often use a multimodal approach to tackle acute post-operative pain.

Though continuous femoral nerve block (CFNB) improves analgesia after TKA, breakthrough pain can still occur. Peri-articular (PA) injections of a combination of a local anesthetic, morphine, epinephrine and ketorolac have been shown to decrease opioid consumption and postoperative pain after TKA. With the following study, we set to inquire whether the addition of a PA injection of ropivacaine, morphine, epinephrine and ketorolac provided superior postoperative analgesia when used in combination with CNFB after TKA.

Methods

This is a one center, prospective, placebo-controlled, double blind study. All eligible subjects had TKA under neuraxial anesthesia with postoperative CFNB and were randomized to receive either a PA injection of the study mixture (treatment group) or a sham injection (control group) (Figure 1). The injectate was administered during wound closure and infiltrated around the knee joint into the posterior aspect of the capsule, medial and lateral collateral ligaments and the subcuticular structures. Subjects consumption of morphine PCA for breakthrough pain throughout the postoperative period was recorded as a primary outcome variable. Data was analyzed using Students unpaired, 2 tailed t test.

Results

At the time of this analysis, 18 patients completed the study protocol (treatment group n=11; control group n=7). Mean PCA consumption at 4 hours after surgery was significantly less in the treatment group compared to controls (p=0.035) (Figure 2). Though not statistically significant, this trend appears to continue for the first 24 hours postop but by 2 days there was no longer any difference. There was no difference in maximal knee flexion with physical therapy (PT) assistance on postop day 2 between the two groups; however there seemed to be greater improvement in the treatment group when comparing flexion before and after PT (Figure 3).

Discussion

These data demonstrate that TKA patients who receive a PA injection of ropivacaine, morphine, ketorolac and epinephrine have a decreased requirement for breakthrough systemic opioid therapy in the early postoperative period. Moreover, these patients appear to have a more robust response to physical therapy two days after surgery. Further study is ongoing to evaluate whether the addition of a PA injection is indeed a reliable addition to a multimodal analgesic approach for TKA patients.

References:

Busch et al., Efficacy of Periarticular Multimodal Drug Injection in Total Knee Arthroplasty A Randomized Trial. JBJS. 2006 Vol 88-A , No 5

Vendittoli et al., A multimodal analgesia protocol for total knee arthroplasty. JBJS 2006; 88:282-289.

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SINGLE-SHOT OR CONTINUOUS INFUSION FEMORAL NERVE BLOCKADE FOR TOTAL KNEE ARTHROPLASTY? A RANDOMIZED, PLACEBO-CONTROLLED, DOUBLE-BLIND TRIAL E. Albrecht, D. Morfey, V. Chan, R. Gandhi, A. Koshkin, K.J. Chin, S. Robinson, P. Frascarolo, R. Brull Department of Anesthesia, Toronto Western Hospital and University of Toronto, Toronto, ON, Canada, Department of Anesthesia, Nottingham University Hospitals NHS Trust, Nottingham, UK, Division of Orthopedic Surgery, Toronto, Toronto, ON, Canada, Department of Anesthesia, Centre Hospitalier Universitaire Vaudois and Unive, Lausanne, Switzerland Background

Femoral nerve blockade (FNB) provides excellent analgesia for patients with total knee arthroplasty (TKA). However, FNB can impair quadriceps muscle strength and mobility (1,2), and may even contribute to falls (3). Previous investigations of FNB for TKA are outdated in the setting of modern accelerated clinical pathways (4,5) and the ideal local anesthetic regime to balance pain relief and mobility is unknown. This randomized controlled double-blind trial examined the effect of varying the concentration and volume of a fixed- dose continuous ropivacaine infusion compared to a conventional single-shot FNB on early and long-term functional outcomes following TKA.

Methods

Sixty-nine ASA I-III patients scheduled for TKA were randomized into three groups. A stimulating perineural femoral nerve catheter was inserted preoperatively under ultrasound and stimulation guidance. Surgery was performed under spinal anesthesia and all patients received standard multi-modal analgesia inclusive of intrathecal morphine (up to 0.1 mg) and single-shot sciatic nerve block. In PACU, patients randomized to Group R2 received a 20 mL bolus ropivacaine 0.2% with epinephrine followed by an infusion of ropivacaine 0.2% at 5 mL/h and patient-controlled bolus 5 mL/30min; Group R1 received a 20 mL bolus ropivacaine 0.2% with epinephrine followed by an infusion of ropivacaine 0.1% at 10 mL/h and patient-controlled bolus 10 mL/30min; and, Group NS received a conventional 30 mL bolus ropivacaine 0.375% with epinephrine followed by an infusion of saline 0.9% at 1 mL/h and patient-controlled bolus 1 mL/30 min. The FNB infusion was discontinued at 06h00 on postoperative day (POD) 2. The clinically relevant primary outcome measure was distance walked (m) on the morning of POD 2 after catheter removal. Secondary outcomes measured twice daily included opioid consumption, pain at rest and during physiotherapy (VRS), incidence of opioid-related side effects, satisfaction (VRS), active and passive knee flexion (degrees), manual quadriceps muscle strength testing (pounds), as well as functional recovery at 6 weeks, 3 months, 12 months (WOMAC, SF36 scores) and duration of hospital stay (min). Statistical analysis included the ANOVA and Pearson tests for continuous and non- continuous data, respectively. Significance was considered at p < 0.05.

Results

Patient characteristics were similar between groups. The distance walked on the morning of POD 2 was similar between groups (R2 41 ± 31, R1 37 ± 32, and NS 41 ± 28 m; p = 0.91). No statistically significant differences were detected between groups at any time during the course of the FNB infusion in any of the secondary outcomes, except for passive flexion on POD1 (Table 1 and 2).

Conclusion

Compared to a conventional single-shot local anesthetic injection, we were unable to demonstrate that varying the concentration and volume of a fixed-dose continuous ropivacaine infusion for FNB influences early or long-term functional outcomes in patients undergoing TKA. Based on our current results, we cannot recommend the use of a continuous perineural catheter infusion over a conventional single-shot bolus for FNB for analgesia following TKA.

References:

1. Ilfeld BM, Ball ST, Gearen PF et al. Ambulatory continuous posterior lumbar plexus nerve blocks after hip arthroplasty: a dual-center, randomized, triple-masked, placebo-controlled trial. Anesthesiology. 2008;109:491-501.

2. Barrington MJ, Olive D, Low K, Scott DA, Brittain J, Choong P. Continuous femoral nerve blockade or epidural analgesia after total knee replacement: a prospective randomized controlled trial. Anesth Analg. 2005;101:1824-1829.

3. Ilfeld BM, Duke KB, Donohue MC. The association between lower extremity continuous peripheral nerve blocks and patient falls after knee and hip arthroplasty. Anesth Analg. 2010;111:1552-1554.

4. Capdevila X, Barthelet Y, Biboulet P, Ryckwaert Y, Rubenovitch J, d´Athis F. Effects of perioperative analgesic technique on the surgical outcome and duration of rehabilitation after major knee surgery. Anesthesiology. 1999;91:8-15.

5. Singelyn FJ, Deyaert M, Joris D, Pendeville E, Gouverneur JM. Effects of intravenous patient-controlled analgesia with morphine, continuous epidural analgesia, and continuous three-in-one block on postoperative pain and knee rehabilitation after unilateral total knee arthroplasty. Anesth Analg. 1998;87:88-92.

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[019_Table2] A4

SAPHENOUS (ADDUCTOR CANAL) NERVE BLOCK VS. FEMORAL NERVE BLOCK FOR TOTAL KNEE ARTHROPLASTY: A NOVEL APPROACH FOR POSTOPERATIVE ANALGESIA D. Kim, J.T. YaDeau, Y. Lin, D. Maalouf, R.L. Kahn, E. Goytizolo, A. Manohar, M. Patt, D. Marcello Anesthesiology, Hospital for Special Surgery, New York, NY, USA Background: Optimal pain relief is essential for functional recovery, especially in patients who undergo total knee arthroplasty. Several studies have noted that femoral nerve blocks (FNB) provide superior pain control and shortened hospital stay, in comparison with epidural or intravenous PCA alone (ref 1-2). However, in recent years, studies have reported a small (2% incidence), but significant risk of falls after prolonged motor blockade from FNB's (ref 3). An anatomical study of the adductor canal (AC) has demonstrated that the resulting sensory changes are not limited to the distribution of the saphenos nerve (ref 4). They noted that medial, anterior, and lateral aspects of the knee showed sensory loss extending from the superior pole of the patella to the proximal tibia, without any noticeable motor effect in the quadriceps muscles. The AC may serve as a conduit for more than just the saphenous nerve, possibly including the medial femoral cutaneous nerve, articular branches from the obturator nerve, as well as the medial retinacular nerve. Using anatomical landmarks and an ultrasound device, the nerve can be easily identified and blocked within the AC (ref 5-7). The question our study attempts to answer is: “does the saphenous nerve block provide equivalent analgesia to the femoral nerve block, while avoiding significant motor blockade?” Methods: This was a prospective, double-blinded (patient and data collector), randomized controlled clinical trial evaluating either a FNB or SNB's effect on quadriceps strength and analgesia after total knee arthroplasty. A dynamometer was used to assess quadriceps strength. Patients were instructed to raise their legs three times. After each leg raise, a NRS pain score was recorded. Both operative and nonoperative legs were assessed preoperatively, and 6-8 hours, 24 hours and 48 hours post-anesthesia administration. A pinprick sensory exam was also performed to confirm successful blockade. Results: 38 patients received FNB, 41 patients received SNB. No significant difference was found in demographics (Table 1). While there was no significant difference in dynamometer readings prior to surgery, patients with a FNB had significantly lower dynamometer readings in the recovery room (6-8 hours) versus the SNB treatment group. For postoperative days (POD) 1 and 2, there was no statistical difference in dynamometer results between the two groups. Analysis of NRS pain scores revealed no difference preoperatively, nor 6-8 hours postoperatively. While the NRS pain scores equalized on POD 2, the difference in pain scores were higher in patients with the SNB on POD 1 (P = 0.0034). Comments: This comparison study shows that while there was no difference in pain control 6-8 hours post-anesthesia administration, quadriceps strength was spared more with use of saphenous nerve blockade at the level of the adductor canal. While our study verified adequate analgesia in the recovery room, duration has yet to be optimized. References

1. Anesthesiology. 1999;91:8-15.

2. Anesth Analg. 1998;87:88-92.

3. The Knee. 2009;16:98-100. 4. RAPM. 2009;32(4):369-70.

5. RAPM. 2009;34:(5):486-89.

6. Knee Surg Sports Traumatol Arthrosc. 2008;16:855-858.

7. RAPM. 2009;34(6):578-80.

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[028_Table3] A5

THORACIC PARAVERTEBRAL BLOCKADE DECREASES LENGTH OF STAY AND REDUCES TRANSITION TIME TO ORAL OPIOIDS IN PATIENTS UNDERGOING BREAST SURGERY G.M. Hanna, S.B. Coopey, M.C. Specht, J.M. Winograd, P. Stefanovich, L. Warren, K. Fleischmann Department of Anesthesia, Critical Care and Pain M, Massachusetts General Hospital, Department of Surgery, Division of Surgical Oncolo, Massachusetts General Hospital, Department of Surgery, Division of Plastic and Rec, Boston, MA, USA Preoperative thoracic paravertebral blockade (TPVB) in patients undergoing breast surgery has been shown to reduce postoperative pain, lower opioid requirements on the first postoperative day, and decrease nausea and vomiting. No prior studies have shown a significant decrease in the length of stay (LOS) of patients receiving TPVB. However, these studies evaluating LOS excluded patients undergoing bilateral procedures as well as immediate reconstruction. We report our institutional experience with the use of TPVB in patients undergoing unilateral or bilateral mastectomy with reconstruction (tissue expander or implant placement). One hundred ninety (190) patients were retrospectively identified who underwent preoperative TPVB prior to mastectomy with immediate reconstruction at a single institution in 2010. This group was compared to a similar group of 154 patients who underwent mastectomy with immediate reconstruction without the use of TPVB in 2008. LOS, transition time to oral opioids, and postoperative nausea and vomiting were compared between groups. Mean LOS for the TPVB group (42 hours, range: 17-101) was significantly less compared to the group that did not receive blocks (47 hours, range: 19-102) (p=0.0015). The mean time from end of surgery to conversion to oral opioids was significantly shorter in the TPVB group (15 hours, range: 0-64) compared to the no block group (20 hours, range: 0- 63) (p< 0.001). The incidence of postoperative nausea in the TPVB group (42.8%) was significantly less than in the no block group (54.7%) (p=0.031). We conclude that preoperative TPVB in patients undergoing mastectomy with reconstruction significantly decreases patient length of stay, shortens transition time to oral opioids, and reduces the incidence of nausea.

A6

AMBULATORY CONTINUOUS INTERSCALENE NERVE BLOCKS FOLLOWING ADHESIVE CAPSULITIS MANIPULATION: A RANDOMIZED, DOUBLE-MASKED, PLACEBO-CONTROLLED PILOT STUDY- FINAL N. Malhotra, S. Madison, S.R. Ward, N. Sandhu, E.R. Mariano, V.R. Loland, B. Ilfeld Anesthesiology, University of California, San Diego, Radiology, Orthopaedic Surgery, Bioengineering, University of California, La Jolla, Anesthesiology, San Diego, San Diego, Anesthesiology, VA Palo Alto Heath Care System, Stanford University, Palo Alto, CA, Anesthesiology, University of Washington, Seattle, WA, USA Background:

Shoulder adhesive capsulitis is often treated with manipulation under anesthesia to physically lyse scar tissue around the joint capsule (1). A critical component of successful treatment includes frequent subsequent range-of-motion exercises to ensure the pathology does not recur. Unfortunately, shoulder motion following manipulation is often painful, greatly limiting adherence to the exercise regimen which can result in a return of capsular adhesions (2). Continuous interscalene blocks have been shown previously to improve rehabilitation outcomes in patients following major shoulder surgery (3). In this randomized, double- masked, placebo-controlled pilot study we tested the hypothesis that a three-day continuous interscalene nerve block in addition to the customary single injection interscalene block for shoulder manipulation improves both analgesia and shoulder range-of-motion. Methods:

Following IRB approval, written informed consent and baseline range-of-motion measurements of passive glenohumeral abduction, subjects undergoing shoulder manipulation for refractive adhesive capsulitis received an ultrasound-guided posterior approach (4) interscalene block using a stimulating perineural catheter. Mepivacaine 1.5% with epinephrine, 2.5µg/mL (40mL), was injected via the catheters. Following shoulder manipulation, subjects were randomized to receive perineural ropivacaine 0.2% or normal saline in a double-masked fashion (basal 8mL/hr, bolus 4mL, lockout 30 min, reservoir volume 1000mL) using an electronic portable infusion pump for three days. Subjects were called nightly for data collection and presented to the surgeon´s office for range-of-motion measurements on postoperative day 1. Because this was a pilot study, statistical analysis was not performed. Results:

Four subjects had successful catheter insertion and interscalene brachial plexus block. Subjects receiving post-manipulation ropivacaine had better pain scores, decreased opiate use during the infusion from POD 0-4 (Figures 1-3), and increased range-of-motion in passive shoulder abduction on POD 1 (Table 1). Conclusions:

The addition of a three-day ambulatory continuous interscalene nerve block to a single- injection brachial plexus interscalene block for patients undergoing manipulation for shoulder adhesive capsulitis provides analgesia during the infusion and may improve shoulder range- of-motion the day after manipulation. The results of this pilot study suggest that a large, randomized clinical trial is warranted. References:

1. Murnaghan JP.Adhesive capsulitis of the shoulder.Orthopedics 1988; 11:153-8.

2. Yamaguchi K, et al.Postoperative pain control following arthroscopic release of adhesive capsulitis.Arthroscopy 2002;18:359-65.

3. Ilfeld B, et al.Joint range of motion after total shoulder arthroplasty with or without a continuous interscalene nerve block.Reg Anesth Pain Med 2005;30(5):429-33.

4. Mariano E, et al.Interscalene perineural catheter placement using an ultrasound-guided posterior approach.Reg Anesth Pain Med 2009;34:60-63.

5. Bure S. et al. Idiopathic adhesive capsulitis of the shoulder. Knee.Surg.Sports Traumatol.Arthrosc.2007;15:1048-54.

6. Shah N. et al.Shoulder adhesive capsulitis. Br.J Gen.Pract.2007;57:662-7.

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A7

PERIOPERATIVE OUTCOMES IN PATIENTS WITH ANXIETY AND DEPRESSION UNDERGOING ORTHOPEDIC SURGERY O. Stundner, M. Kirksey, Y.L. Chiu, M. Mazumdar, L. Poultsides, P. Gerner, S.G. Memtsoudis Department of Public Health, Deparment of Anesthesiology, Department of Public Health, Weill Cornell Medical College, Department of Orthopedic Surgery, Hospital for Special Surgery, Weill Cornell Medica, New York, NY, USA, Department of Anesthesiology and Intensive Care, Salzburg University Hospital, Salzburg, Austria, 6Department of Anesthesiology, Hospital for Special Surgery, Weill Cornell Medica, New York, NY, USA Background: Depression and anxiety are prevalent psychiatric disorders in patients undergoing surgery. However, little is known about their impact on outcomes in the perioperative setting. This study is intended to gain insight into epidemiology and effects on perioperative morbidity, mortality, length of hospital stay, discharge and cost. Methods: We obtained the National Inpatient Sample from the Hospital Cost and Utilization Project for each year between 2000 and 2008. Entries indicating the performance of primary total hip and knee arthroplasty (THA, TKA) were identified and separated into three groups: 1) those with concomitant diagnosis of depression (D) or 2) anxiety (A), respectively, and 3) those without these diagnoses (N). Patient demographics and health care system related parameters were compared. The outcomes of major complications, non-routine discharge, length of hospital stay and hospitalization charges were assessed for all three groups. Regression analysis was performed to identify if the presence of psychiatric comorbidity was an independent risk factor for each outcome. Results: In total, an estimated 5,896,198 THA and TKA were performed in the US between 2000 and 2008. The prevalence of both depression and anxiety significantly increased over time (depression: 4-fold increase, peak of 3.20%; anxiety: 3-fold increase, peak of 3.94%). Patients with either condition had: longer length of stay (D (depression) 4.02 days, A (anxiety) 3.94 days vs. N (none of these diagnoses) 3.93 days, P< 0.0001); higher hospital charges (D $ 14,461, A $ 14,265 vs. N $ 13,981, P< 0.0001); higher rates of non-routine discharges (D 78.95%, A 78.97% vs. N 74.93%, P< 0.0001); higher comorbidity index (D 0.68, A 0.57 vs. N 0.55, P< 0.0001). When controlling for covariates (type of surgery, age, gender, race and comorbidities), the presence of depression or anxiety was associated with significantly decreased odds for major life- threatening complications (D vs. N: 0.89, P< 0.0001; A vs. N: 0.91, P< 0.0001) and in- hospital mortality (D vs. N: 0.48, P= 0.0029; A vs. N: 0.54, P=0.0012). Conclusion: Patients suffering from depression or anxiety require more healthcare resources in a perioperative setting, reflected in longer hospitalizations, fewer routine discharges and higher hospital costs. However, this elevated level of attentiveness may beneficially influence short-term morbidity and mortality

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[001_Table2]

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[001_Figure1] A8

AN IN VITRO STUDY TO EVALUATE THE UTILITY OF THE "AIR TEST" TO INFER PERINEURAL CATHETER TIP LOCATION J.M. Kan, T.K. Harrison, T.E. Kim, S.K. Howard, A. Kou, E.R. Mariano Anesthesiology, VA Palo Alto Heath Care System, Stanford University, Anesthesiology, Palo Alto, Palo Alto, CA, USA Background: Perineural local anesthetic infusion effects can be determined by accurate positioning of perineural catheters. While ultrasound may improve the efficiency of insertion, determining exact catheter tip position remains difficult. The “air test” has been described as a means of inferring this position, but the overall utility, sensitivity, specificity, and positive and negative predictive values of this test have not been previously studied.

Methods: An in vitro model was developed in which a bovine tendon representing a target nerve was laid between the fascial planes of two adjacent muscle groups approximately 4 cm deep in a porcine hind quarter. Thirty catheters (Arrow FlexTip Plus, Teleflex Medical, Research Triangle Park, NC) were randomly assigned to either “correct” (tip directly below the target) or “incorrect” (tip beyond the target) positions. All catheters were inserted by one practitioner with expertise in ultrasound-guided perineural catheter placement using a short-axis, in-plane technique and confirmed by gross visual inspection by an observer. A second expert, blinded to actual catheter location, was then asked to assess catheter position using ultrasound alone (pre-air) and after the injection of 1 ml air via the catheter (post-air). Sensitivity, specificity, and positive and negative predictive values were calculated. Differences in proportions were compared using the z test or McNemars test. P< 0.05 was considered statistically-significant.

Results: One out of 30 catheters was not placed according to the randomization assignment; therefore, there were 16 “correct” and 14 “incorrect” catheter placements. Ultrasound scanning alone (pre-air) identified true catheter location 21/30 times (70%) compared to 26/30 (87%) post-air (p=0.13). Sensitivity, specificity, and positive and negative predictive values are presented in Table 1. Compared to chance (50% success), the air test resulted in a significantly greater area under the ROC curve (0.862; p< 0.01; Figure 1) while ultrasound alone did not (p=0.07). Following air injection, the expert changed his assessment to match actual catheter tip position 6 out of 7 (86%) times.

Conclusions: Based on this in vitro model, the air test may aid the expert clinicians assessment of perineural catheter tip position. It is not yet known whether or not this test has any utility for the novice regional anesthesiologist. Further, the relative benefits and drawbacks of this technique in comparison to other methods remain to be investigated.

References: 1) Anesth Analg 2011;113:904-25; 2) Br J Anaesth 2002;89:254-9

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EPIDURAL CLONIDINE AS A SOLE ANALGESIC AGENT DURING AND AFTER ABDOMINAL SURGERY A.A. Abd-Elsayed, S. Zaky University of Cincinnati, Cincinnati, Anesthesiology, Cleveland Clinic, Cleveland, OH, USA Introduction:

Alpha2-Adrenergic mechanisms of analgesia have been exploited for more than 100 years. Most investigations studying the analgesic effect of alpha2 adrenoceptor agonists after operation included previous or concomitant administration of other analgesic drugs such as local anesthetics or opioids. 1 Because clonidine can potentiate the analgesic effect of these drugs, the importance of its own intrinsic analgesic effect has been difficult to establish. 2 Our study aimed at comparing the intra and post-operative effects of epidural clonidine versus bupivacaine for patients undergoing lower abdominal surgeries.

Patients and methods:

Our study included 40 patients 18-50 years of age and with ASA I or II. All patients were scheduled for elective lower abdominal surgeries. After obtaining an informed consent and IRB approval, patients were randomly divided into two groups each composed of twenty patients. Patients and investigators were blinded to the medication used. Group I (n = 20) received initial dose of epidural clonidine of 10 ug/kg (Max 600 ug) in 7 ml saline in 15 minutes followed immediately by infusion of 6 ug/kg/h (7 ml/h) for 12 hours. Group II (n = 20) received initial dose of 7 ml of bupivacaine 0.5% in 15 minutes followed immediately by infusion of bupivacaine 0.2% (7 ml/h ) for 12 hours.

Results:

Pain scores were significantly lower in the clonidine group compared to the bupivacaine group (1.5 ± 0.5 and 3.4 ± 1, respectively). Sedation scores were significantly higher in the clonidine group. Opioid requirements during intraoperative and postoperative period also showed a significant difference between the two groups. Respiratory rate and hemoglobin oxygen saturation were similar in the two groups. Values for systolic and diastolic blood pressure change from baseline were -21.2 ± 3.9% and -13.3 ± 2.8% in the clonidine group versus -17.1 ± 3.6% and -8.8 ± 3.1% in the bupivacaine group. Lowest mean intraoperative systolic and diastolic blood pressures expressed as a percentage change from baseline were similar. Rate in the clonidine group was reduced -10 ± 3.3%, while it was increased by 22 ±15.1 in the bupivacaine group. Postoperative nausea and vomiting were significantly less in the clonidine group. Urinary retention was significantly higher in the bupivacaine group. Pruritus and shivering were significantly higher in the bupivacaine group.

Conclusion:

Clonidine can be used for intra and post-operative analgesia as a sole agent. Epidural clonidine provided effective intra and post-operative analgesia when given with adequate dose in selected patients. It reduced the need for rescue intravenous pain medications, and had a prolonged action after discontinuation of epidural infusion compared to the more commonly used drug bupivacaine. Further studies on a larger scale are recommended to confirm the findings of our study.

References:

1.Meert TF et al: Potentiation of the analgesic properties of fentanyl-like opioids with a2- adrenoceptor agonist in rats. Anesthesiology 1994; 81:677-88.

2.Eisenach J. et al: a2-adrenergic agonists for regional anesthesia: A clinical review of clonidine (1984-1995). Anesthesiology 1996; 85: 655-74.

A10

CAUDAL ULTRASOUND: A SAFE AND RELIABLE WAY TO IDENTIFY LOCAL ANESTHETIC IN THE INFANT CAUDAL EPIDURAL SPACE BY THE NON-EXPERT ULTRASONOGRAPHER G.R. Lauder, A. Robinson, E. Whyte, N. West Department of Pediatric Anesthesia, Department of Radiology, British Columbia Children's Hospital, Department of Pediatric Anesthesia, Vancouver, Vancouver, BC, Canada Introduction: The Caudal Epidural (CE) regional block technique is firmly established in pediatric anesthesia and provides peri-operative analgesia for infants receiving surgery below the umbilicus. The current standard blind technique of CE analgesia involves the injection of local anesthetic (LA) via the sacral hiatus into the CE space, usually as a test dose followed by a main dose. The test dose is used to confirm correct CE placement, but is unreliable (1). Quoted failure rates for this blind technique are up to 25% (2). LA may be inadvertently injected into a blood vessel, into CSF, subperiosteally, subcutaneously or peri-rectally. This may result in one or more of the following: regional block failure, inability to use alternative LA techniques as maximum LA dose has already been used, the need to use systemic opioids for postoperative analgesia and the potentially devastating consequence of systemic LA toxicity from intravascular injection. Blind CE regional block therefore exposes this vulnerable patient population to the potential for significant morbidity. Ultrasound (US) imaging has been shown by experts to enable direct visualization of the cannula and the LA as it is administered in the CE space (3). We aimed to show that a novice ultrasonographer could use US imaging to reliably confirm placement of LA in the CE space in infants.

Methods: Following ethical approval and informed consent, 40 infants, ASA I & II, less than 6 months of age, undergoing elective surgery with planned CE analgesia, were recruited. Demographic data were collected. Following induction of anesthesia, CE injection was performed with the aid of US control by the studys principal investigator, an experienced anesthesiologist, but a novice in the use of US imaging of caudal injections. Real-time visual identification of the CE space, the cannula and the test dose were noted and cephalad spread (height) of the main dose was estimated where possible. If visualized, the injection of the main dose was tracked. The US images were recorded and subsequently reviewed by an independent expert sonographer. The test and main doses administered were 0.1ml/kg and 0.9ml/kg of 0.25% bupivacaine with 1/200,000 epinephrine respectively.

Results: Figure 1 illustrates typical US images recorded during examination of the CE space and administration of LA. Table 1 demonstrates a learning curve for identification of anatomical structures, cannula and LA doses (9 cases for this investigator). US technique improved with experience and enabled confirmation of test dose placement in all post- learning curve cases.

Conclusion: US imaging is a non-invasive and efficient technique for verifying correct placement of LA in the CE space in infants. There is an associated learning curve. Once mastered, it provides a timely and extremely reliable way to ensure the test dose is correctly placed. We propose that US imaging of CE regional blocks in infants can be adopted by any pediatric anesthesiologist and should become an international standard of care to improve the safety and effectiveness of CE analgesia in infants.

References: 1. Polaner et al, 2010, Anesth Analg, 110:41-5; 2. Chen et al, 2004, Anesthesiology, 101:181-4; 3. Lundblad et al, 2010, Paediatr Anaesth, 21:121-7

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A COMPARISON OF INTRANEURAL AND EXTRANEURAL YOUNGS MODULUS IN THE THIEL EMBALMED HUMAN CADAVER S. Munirama, J. Joyce, R. Eisma, M. Columb, G. Corner, S. Cochran, R. Soames, G. McLeod Anaesthesi, Ninewells Hospital, Medical Ultrasound Group, Institute of Medical Science & Technology, Anatomy, Centre for Anatomy and Human Identification, Dundee, 3Anaesthetics, Manchester, Manchester, Medical Physics, Niewells Hospital and Medical School, Biophysical Science and Engineering, Institute of Medical Science & Technology, Dundee, Anatomy Centre for Anatomy and Human Identification, Angus, Anaesthetics, Institute of Aademic Anaesthesia, Dundee, UK Introduction

Despite the widespread adoption of ultrasound guided regional anesthesia, no evidence yet suggests any reduction in the incidence of inadvertent intraneural injection during peripheral nerve block.

There is a need to develop new technologies in order to measure different tissue properties and, in doing so, differentiate between intraneural and extraneural anatomy and characterize spread of local anaesthetic

Using shear wave technology, Youngs modulus has been measured in a wide range of human tissue including muscle, tendon and bone but not, to our knowledge, in peripheral nerve.

The primary objective of the study was the comparison of Youngs modulus in intraneural and extraneural tissue in Thiel embalmed human cadavers and secondary objectives were comparison of Youngs modulus between nerves and reproducibility of Youngs modulus between raters.

Materials and Methods

The study was conducted on two Thiel-embalmed male human cadavers, donated to medical science according to the Anatomy Act (Scotland) 2006. Two anesthetists experienced in UGRA were responsible for acquiring all measurements.

For each scan, B-mode imaging was used to identify the chosen nerve root or nerve in the cadaver. Once a satisfactory greyscale image was obtained, SWE was initiated and a colour map of Youngs modulus was overlaid on an identical, adjacent B-Mode image. Each anesthetist identified a circular region of interest (ROI) 3 mm in diameter corresponding to the centroid of each nerve or nerve root (C6 for interscalene) and to a specific area out with the nerve, overlapping adjacent muscle.

Using information from a pilot study and a prediction interval approach, it was decided that at least 20-paired measures of each nerve location were needed in order to show a 5% outlier. Therefore, for the main study a total of 240 images were taken (2 cadavers, 3 nerves, 2 anesthetists and 20 repeated measures). The primary endpoint was the measurement of Youngs modulus in kPa, presented as the geometric mean (SD), and the end of study was defined as the last recording of Youngs modulus.

Block randomisation was undertaken to nerve location (interscalene nerve roots, median and sciatic nerves) with equal allocation to cadaver, location and operator.

Distribution of data was assessed using probability plots. Concordance between raters used the intraclass correlation. Geometric means (95% CI) were used to account for positive continuous data then log transformed. Linear mixed models with maximum likelihood estimation (MLE) were used to assess effects such as intraneural and extraneural sites, nerve locations, cadavers and raters. Significance was defined at P < 0.05 (two-tailed).

Results

A total of 167 measurements were eligible for analysis, 117 in the first cadaver and 50 in the second cadaver. Intraclass correlation between raters was 0.73.

Overall, mean (95% CI) Youngs modulus was greater for neural 26.8 (24.6 to 29.2) kPa compared to extra-neural sites 6.2 (5.7 to 6.8 )kPa, p < 0.001 (Table 2). For each location (neural and extra-neural data combined) mean (95% CI) Young†™s modulus was greater for interscalene 25.6 (23.2 to 28.3) kPa and median 24.3 (21.8 to 27.0) kPa locations compared to sciatic 3.5 (3.0 to 4.0) kPa, p < 0.001 (Fig 1).

For both intraneural and extraneural sites, Youngs modulus was greater for interscalene and median compared to sciatic locations (p < 0.001). However, there was no difference between interscalene and median locations (intraneural, p = 0.07; extraneural p = 0.46).

Conclusion

Our study has shown greater Youngs modulus in intraneural tissue compared to extraneural muscle in Thiel-embalmed human cadavers. Youngs modulus was reproducible between raters and greater in interscalene and median nerves compared to sciatic nerves

A12

THE INTEREST OF THE TRANSVERSUS ABDOMINIS PLANE BLOCK FOR POSTOPERATIVE ANALGESIA DURING HYSTERECTOMY M. Ayedi, M. Smaoui, R. Barkia, S. Akrout, H. Bensoltana, A. Derbel, K. Chaabane, M. Guermazi, K. Kolsi Anesthesiology and Intensive Care, Obstetric And Gynecology, Hedi Chaker Hospital, Sfax, Tunisia Background and Goal of Study: The abdominal wall is a significant source of pain af ter abdominal surgery. Several methods are performed to control the pain af ter a total abdominal hysterectomy. The transversus abdominis plane (TAP) block is an expanding regional anesthesia technique that provides analgesia following abdominal surgery. The aim of this study is to evaluate analgesic ef ficacy of the TAP block in patients undergoing total abdominal hysterectomy via laparotomy.

Materials and methods: Thirty-six patients aged between 20 and 65 years with ASA I-II physical status, proposed to elective total abdominal hysterectomy were included in this prospective, randomized, double-blind study. All patients received general anesthesia induction by thiopental 5mg/kg, cisatracurium 0.15 mg/kg and remifentanil 1µg/kg. Then the patients were randomized into two groups, G1: injection of 20 ml bupivacaine0.25% in the plane of the transversus abdominis on each side and G2 : injection of 20 ml saline.

Maintenance of anesthesia with propofol 6mg/kg/h, remifentanil 0.1µg/kg/min set according to the hemodynamic changes and cistracrium. In addition a standard postoperative analgesia by 1g paracetamol, 0,1mg/kg morphine and 100mg ketoprofen was given to both groups. In postanesthesia care unit, complementary analgesia was made by morphine titration 2mg every 5min if the verbal numerical rating scale (VNRS)>3, the first request and total doses of morphine was recorded. VNRS was evaluated at rest and af ter mobilizing the knees for the 48 postoperative hours. Statistical study was performed using

SPSS 18.0 for Windows, the analyses of data by chi-square and t-test , the results were considered as significant for p< 0.05.

Results and discussion: The demographic characteristics and duration of the surgery were comparable between the two groups. The TAP block reduced the VNRS at rest and at mobilizing knees until 48h (p< 0.05), the total doses of morphine (2.56mg vs 7.50mg; p< 0,001) and the intraoperative use of remifentanil (512µg vs 804µg; p< 0.001).There was no dif ference in side ef fects of morphine, except for vomiting af ter 60, 90 and 120min which were lower for G1 (P< 0,05). We didn't observe any complications related to the TAP block.

Conclusion(s): The TAP block with 0,25% bupivacaine significantly reduced pain af ter elective total abdominal hysterectomy. It also reduced perioperative use of opioids

A13

AMBULATORY INTERSCALENE CATHETERS FOR ROTATOR CUFF SURGERY: A CASE SERIES A. DiStefano, L. Asaro, V. Edwin, E. Shepard, J. Haugh, E. Joe, M. Dimino, P. Lee Kernan Anesthesiology, University of Maryland School of Medicine, Baltimore, MD, USA Background: Recent evidence has shown that continuous interscalene catheters can improve analgesia beyond 48 hours after moderately painful shoulder surgery, including arthroscopic rotator cuff repair. Most of these procedures are done on an outpatient basis, therefore these catheters must be effectively managed with patients at home. Not much has been reported about overall patient satisfaction with ambulatory catheters. We sought to compare ambulatory interscalene catheters with single-shot interscalene injections for same-day arthroscopic rotator cuff repair to investigate whether our current practice improves anesthesia care and patient satisfaction.

Methods: As part of an internal quality assurance initiative starting from August through November of 2011, patients scheduled for arthroscopic rotator cuff repair who received interscalene catheters were surveyed. All catheters were placed pre-operatively under the supervision of an attending anesthesiologist with sterile precautions and real-time ultrasound guidance. Local anesthetic, 30ml of 0.5% plain Ropivicaine, was delivered both via the tuohy needle and catheter to visualize correct placement. Both patients and their caretakers were counseled post-op on catheter site care, electronic pump function, and signs of local anesthetic toxicity, along with the number to reach an attending anesthesiologist 24 hours a day. Patients that did not receive catheters had single injection interscalene blocks with either 0.5% Ropivicaine or Bupivicaine +/- adjuvants, depending on anesthesia attending preference. All patients were sent home with written surveys to be completed and mailed back on post-op day #2.

Results: At the time of this writing, 31 completed surveys have been received (22 catheter, 9 single shot). The response rate was 59% (22/37) for the catheter group, 42% (9/21) in single shot group. 2 surveys in the catheter group were not fully completed, leaving 20 surveys for analysis. 16 patients with catheters (80%), rated their satisfaction with their pain control either a 9 or 10 (most satisfied), the average being 9. Of the single shot group, only 4/9 (44%) rated their satisfaction with pain control a 9 or 10, with the average rating a 7. 3 patients (14%) reported ever experiencing a pump malfunction at home. 5 (23%) patients noticed shortness of breath during the infusion, 5 patients (23%) reported distress from the sensation of numbness in the arm. Few patients reported any problem with the catheter, 1 patient reported leakage of fluid, 2 patients (10%) reported any discomfort with removing it at home. Of note, 1 patient reported symptoms that could have been consistent with local anesthetic toxicity (headache, metallic taste in mouth) prior to catheter removal. Despite these few issues, almost all patients (95%) would recommend this technique to others.

Conclusion: This ongoing survey has so far yielded a small number of responses, however there is a trend toward increased patient satisfaction with pain control in the ambulatory catheter group compared with the single injection group. The issues that did arise involving pump malfunctions and symptoms suggestive of toxicity underscores the counseling and close outpatient follow-up this technique necessitates

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A14

THE TRANSVERSUS ABDOMINIS PLANE BLOCK VERSUS SPINAL MORPHINE FOR POSTOPERATIVE ANALGESIA AFTER CAESAREAN DELIVERY M. Ayedi, M. Smaoui, S. Abidi, I. Souissi, A. Derbel, J. Zouari, K. Chaabane, M. Guermazi, K. Kolsi Anesthesiology and Intensive Care, Obstetric And Gynecology, Hedi Chaker Hospital, Sfax, Tunisia Background and Goal of Study: Spinal morphine is an ef fective analgesic technique for analgesia af ter cesarean delivery (CD) [1], but it is punctuatedwith side ef fects. Recently, the transversus abdominis plane (TAP) block hasbeen studied for analgesia af ter CD and was ef fective compared to placebo[2]. The purpose of this study is to compare the analgesic ef ficacy of TAP block to spinal morphine af ter CD.

Materials and methods: In this prospective, double-blind study, six ty women undergoing elective CD were randomized to undergo either subarachnoid morphine (group SAM; n = 30) or TAP block (group TAP; n = 30). Patients received bupivacaine spinal anesthesia combined with morphine 0.1 mg in group SAM and received saline in group TAP. At the end of surgery, bilateral TAP block was performed using saline in group SAM or using bupivacaine 0.25% in group TAP with 20 mL on each side. Postoperative analgesia for the first 48 hours consisted of scheduled oral paracetamol and rectal ketoprofen; IV nefopam were administered up on patient request. The primary outcome was the dif ference in visual analog scale pain scores at rest and on movement during the first 48 postoperative hours. Other outcomes assessed were first analgesic request, analgesic consumption, maternal satisfaction, and incidence of adverse ef fects.

Results and discussion: The demographic characteristics were similar in both groups. The mean visual analog scale pain scores at rest and on movement until 48 postoperative hours were not dif ferent between the 2 groups. Median (range) time to first analgesic request was similar in both groups 24 (12-48) hours in group SAM versus 24 (2-48) hours in group TAP; (P>0.05). Median (range) of nefopam doses received in the first 48 hours was 40 (0-80) mg in group SAM versus 50 (0-80) mg in group TAP (P>0,05). The incidence of nausea and vomiting was significantly higher in group SAM than in group TAP (50% versus 15%; P=0.02 and 33% versus 3%; P=0.03 respectively).

More patients developed pruritus in group SAM than in group TAP (40% versus 3%; P=0,01). There were no complications associated with the performance of the block.

Conclusion(s): As part of a multimodal analgesic regimen, the TAP block provided equivalent analgesic ef ficacy than spinal morphine up to 48 postoperative hours af ter CD, with fewer side ef fects.

References:

[1] Anesthesiology 1999; 91: 1919-27

[2] Anesth Analg 2008; 106: 186 -91

A15

A LESSON IN ANATOMY RELEARNED: ABSENCE OF INVESTING FASCIA UNDER THE STERNOCLEIDOMASTOID MUSCLE - TRANSIENT PARTIAL BRACHIAL PLEXUS BLOCK COMPLICATING ULTRASOUND-GUIDED ACCESSORY NERVE BLOCK PERFORMED FOR DIAGNOSIS AND TREATMENT OF MAYOFASCIAL PAIN IN THE TRAPEZIUS MUSCLE: A CASE SERIES F.W. Abdallah, R. Brull, A.V. Morgan Anesthesia, University of Toronto, Toronto, ON, Canada Background

Myofascial pain syndrome (MPS) is a musculoskeletal non-inflammatory pain refractory to pharmacological treatment frequently affecting the trapezius muscle. Neuropathy of the accessory nerve innervating the trapezius and involuntary trapezius contractions are proposed explanations to this syndrome. Trapezius motor block serves as a diagnostic and therapeutic block that relaxes painful contractions and reduces pain transmission. An ultrasound-guided (USG) accessory nerve block below the posterior edge of the sternocleidomastoid muscle (SCM) has recently been described.1

Methods

Seventy two patients diagnosed with MPS in the SCM following work up that excluded other causes were consented to accessory nerve block. Unilateral USG blocks were performed with a 22G blunt needle. The posterior border of the SCM was scanned to localize nerve, first at the cricoid level and then in a cranial-caudal fashion when nerve was not found. Nerve stimulation eliciting trapezius twitch confirmed needle position and excluded phrenic nerve. Perineural injection targeting circumferential spread was performed using 3 mL of 0.25% bupivacaine mixed with epinephrine 1:200,000. Patients were assessed for pain relief and newly onset sensory or motor deficits at 10 and 20 minutes after injection.

Results

Complete pain relief occurred in 46 patients (64%), significant pain relief in 18 (25%), minor pain relief in 5 (7%), and 3 (4%) reported no change. A high incidence of undesirable nerve blocks was observed. This included partial or complete superficial cervical plexus (SCP) block in 64 patients (89%), overt phrenic nerve paresis in 22 (31%), and, importantly, partial brachial plexus block in 19 (26.4%).

Discussion

While incidence of SCP and phrenic block may be attributed to anastomosis with accessory nerve for the former2 and anatomic proximity to accessory nerve for the former3 and the latter,4 the brachial plexus is a deeper structure theoretically shielded by investing and deep cervical (prevertebral) fascial layers. However, recent anatomic evidence suggests absence of investing fascia between SCM and trapezius muscles.5, 6 Also, potential spaces of fatty connective tissue outside the prevertebral fascia deep to the SCM communicate and are continuous with the subcutaneous tissue via potential channels of fatty tissue between the muscles.7 Additionally, “pores” in the prevertebral fascia where nerves pierce it may allow flow of injectate across and to the deep cervical space.8 As a result, deep and superficial spaces of the neck virtually act as a single space.9 Finally, carotid and SCM sheaths limit anterior spread of injectate while trapezius sheath limits posterior and lateral spread; this phenomenon amplifies the volume spread of injectate by a factor of two and favors a cranio- caudal spread to involving C1-C7 roots.10 This anatomical hypothesis explaining how local anesthetics deposited below SCM diffuse freely into deeper layers of the neck to the brachial plexus roots has also been proposed to interpret the lack of analgesic difference between SCP block and deep cervical plexus blocks,6, 11, 12 as well as SCP and intermediate cervical plexus blocks performed for carotid endarterectomy.13

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EFFICACY EVALUATION OF AN ORALLY INHALED DIHYDROERGOTAMINE(MAP0004) IN TREATING RESISTANT MIGRAINE INCLUDING MIGRAINE WITH ALLODYNIA, MORNING MIGRAINE, DISABLING MIGRAINE AND MIGRAINE TREATED LATE S. Kori, S. Tepper, N. Mathew, J. Saper, P. Winner, F. Freitag, S. Borland, B. Hu, S. Silberstein MAP Pharmaceuticals Inc, Mountain View, CA, Cleveland Clinic Foundation, Cleveland, OH, Houston Headache Clinic, Houston, TX, Ann Harbor, Ann Harbor, MI, Palm Beach Headache Center, West Palm Beach, FL, Baylor University Medical Center, Dallas, TX, 8Thomas Jefferson Headache Center, Philadelphia, PA, USA Background: Triptans are not likely to relieve migraine associated with cutaneous allodynia, morning migraines, and migraine attacks late in their course. Injectable dihydroergotamine (DHE) has been used to treat such nonresponsive migraines for decades; however, this formulation is inconvenient to administer and is often associated with nausea. MAP0004 is a self-administered, novel inhaled form of DHE in development, given at a 1.0 mg nominal (~0.5 mg systemic) dose, with Tmax and AUC similar to those of IV infusion but with markedly lower Cmax.

Methods: This is a post-hoc analysis of a large randomized, double-blind, placebo-controlled, two-arm, multicenter study. The presence of allodynia at the time of drug administration was determined by a standard questionnaire. Time to treatment was determined using an electronic diary. Morning migraine was defined as headache occurring prior to 7 AM.

Results: 903 patients were randomized, and 792 who treated 1 qualifying headache were included in primary analysis (MAP0004 n=395; placebo n=397). Overall, 418 (53%) of patients reported allodynia at the time of treatment (MAP0004 n=216; placebo n=202). Of the patients with allodynia, 57% of patients treated with MAP0004 reported pain relief at 2 hr vs 34% of those who received placebo (P< 0.0001). In those without allodynia at the time of treatment, 2-hour pain relief was achieved in 60% of patients treated with MAP0004 and 35% treated with placebo (P< 0.0001). Two-hour pain freedom was achieved in 30% of MAP0004-treated patients with allodynia (vs 8% with placebo; P< 0.0001) and in 27% of those without allodynia (vs 12% with placebo; P< 0.0002). Pain-free rate at 2 hr with MAP0004 in patients with morning migraine was 21% (4% on placebo; P=0.004) compared with 30% for migraines occurring at times other than the morning (12% on placebo; P< 0.0001). There was no correlation between time to treatment of migraine and pain relief or pain free rates at 2 hr. MAP0004 was equally effective in severely disabled and less disabled migraine patients.

Conclusions: In this trial, MAP0004 was statistically similar in each case in treating migraine with and without allodynia, morning migraine, disabling migraine, and migraine treated late in its course. MAP0004 has the potential to treat migraines that often are resistant to other acute migraine therapies.

A17

ARE WE FOLLOWING THE PARTY LINE? S. Patel, A. Lansdown, P. McHardy, C. McCartney Anesthesia, Sunnybrook Health Sciences Centre, Anesthesia, Toronto, Toronto, ON, Canada Introduction The first Guidelines for Fellowship Training in Regional Anesthesiology (RA) and Acute Pain Medicine were first published in 2005 by ASRA. The guidelines are reviewed every 3 years and the most recent revision was published in 2011. The purpose of this collaboration is to recommend a framework to develop modern and comprehensive fellowship training in RA and pain medicine. The guidelines are not meant for accreditation and there is no assurance that all RA fellowship programs meet these standards. We performed a survey of ASRA affiliated RA fellowship directors to gauge the extent that their programs adhere to the guidelines educational program and evaluation process recommendations.

Methods An online questionnaire was sent to all RA fellowship directors in USA and Canada over 2months in late 2011. Potential recipients were identified by contact details available on the ASRA website and by Internet searches. Fellowship directors were asked to rate how well their program met various (1) educational objectives, and; (2) evaluation recommendations, on a 7-point Likert scale. Information on program organization and resources were not sought.

Results Overall there were a total of 27 respondents (53% response rate) with 21 (78%) from the USA and 6 (22%) from Canada. All respondents were aware of the recently published 2011 guidelines. Almost all fellowships directors rate their adherence to the educational aims of the objectives favorably, particularly in the area of Patient Care (IIc) with 15 (57.7%) rating 7/7 (fully meets) [See figure 1 for full details]. In contrast, a significant proportion of fellowship directors reported poor adherence to the recommendations for fellow assessment. Written evaluation for fellows by faculty was rated 1/7 (not at all meets) in 6 (23%), biannual review was rated 1/7 in 6 (23%) and use of broad peer appraisal in fellow evaluation was rated 1/7 in 9 (35%) [See figure 2 for further details].

Conclusion Curriculum guidelines have been shown to improve outcomes within medicine both clinically and for training. Overall, ASRA affiliated Fellowship programs appear to place significant importance on meeting the educational objectives of the 2011 ASRA fellowship guidelines. In a significant number of programs, however, there may be scope to improve the frequency and transparency of evaluation processes, particularly by gathering written feedback on fellow performance from faculty and including a wider range of allied health and other staff members in the appraisal process. While the results are reassuring, a survey of fellow candidates might draw more frank assessment of the quality of the available programs. Local factors will always make for a wide variety of educational opportunities and experiences in RA fellowship programs. Fellowship directors and associated faculty are responsible for ensuring that their programs, as much as possible, meet ASRA standards. In the future, approaches to standardize fellowship program education and experience could include the completion of compulsory coursework, submission of a logbook of experience or examination of RA fellows.

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A18

PERIOPERATIVE TRANSFUSION REQUIREMENTS AFTER HEPATIC RESECTION: A COMPARISON OF EPIDURAL ANALGESIA VERSUS ON-Q LOCAL ANESTHETIC INFILTRATING CATHETERS J.M. Soliz, R. Gebhardt, L. Feng, W. Dong, A. Holmes, M. Reich, S. Curley Anesthesiology and Perioperative Medicine, Pain Medicine, Biostatistics, M.D. Anderson Cancer Center, Houston, Medical School, UTSA-Health Science Center, San Antonio, Surgical Oncology, M.D. Anderson Cancer Center, Houston, TX, USA Introduction: Hepatic tumor surgery is associated with the possibility of significant perioperative blood loss. Intraoperative and postoperative blood transfusions are often required.[1][2] The choice of pain management technique may affect transfusion requirements following hepatic surgery.[2] Our study retrospectively compares perioperative transfusion requirements in patients undergoing hepatic resection who received epidural analgesia or On-Q local anesthetic infiltrating catheter for postoperative analgesia.

Methods: After approval from the Institutional Review Board (University of Texas M.D. Anderson Cancer Center, Houston, TX), we reviewed data on 143 patients undergoing hepatic resection. The study groups included consecutive patients who received either epidural analgesia or On-Q infiltrating catheters for postoperative pain control. All patients received unilateral or bilateral subcostal incisions for hepatic tumor resection. Patients who received an On-Q catheter for postoperative pain control also received intravenous patient controlled analgesia (PCA). Patients demographic data, preoperative hemoglobin/hematocrit, length of surgery, and estimated intraoperative blood loss were collected and analyzed. Blood component transfusion data was collected for each patient from time of surgery until discharge. Transfusion data collected included number of packed red blood cells (PRBC), fresh frozen plasma (FFP), and platelets. A chi-squared test was used to evaluate the association between two categorical variables. A wilcoxons rank sum test was used to analyze continuous variables.

Results: Patient demographic data, the length of surgery (p=0.22), estimated blood loss (p=0.98), and preoperative hemoglobin/hematocrit (p=0.48, p=0.35 respectively) were similar between the study groups (TABLE A). TABLE B reflects the number of patients in each study group who required at least one blood component transfusion. Transfusions of FFP (p=0.89) and platelets (p= 0.43) were not significantly different. Transfusions of PRBCs in the epidural group (0.4 ± 1 unit) was significantly less (p=0.0066) than the On-Q group (1.1 ± 1.8 unit) over the course of the hospital stay (TABLE C).

Conclusions: Patients who received epidural analgesia for postoperative pain control received less PRBC transfusions compared to patients receiving an On-Q local anesthetic catheter with IV PCA. There was not a significant difference between the two study groups in the transfusion of FFP and platelets. Future prospective randomized trials comparing these analgesic methods will be required to further evaluate transfusion requirements after hepatic surgery.

References:

1. Revie EJ, Massie LJ, McNally SJ, et al. Effectiveness of epidural analgesia following open liver resection. HPB (Oxford) 2011 Mar;13(3):206-11

2. Page A, Rostad B, Staley C, et al. Epidural Analgesia in Hepatic Resection. J Am Coll Surg 2008: 1184-1192

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A19

MINIMUM CONCENTRATION OF ROPIVACAINE TO ACHIEVE SURGICAL ANESTHESIA IN SUPRACLAVICULAR BLOCKS N.C. Lam, V. Chan, C. Amdt, R. Rosett, F. Vagh, A. Zolyomi, T. Yen, N. Doran, E. Baker Anesthesiology, University of New Mexico, Albuquerque, NM, USA, Anesthesia, University of Toronto, Toronto, ON, Canada, Anesthesiology, Albuquerque, Albuquerque, NM, USA Purpose:

This is a sequential allocation dose finding study for the minimum effective anesthetic concentration of ropivacaine to produce surgical anesthesia in supraclavicular blocks.

Background:

The use of ultrasound for peripheral nerve blocks has been shown to reduce the volume of local anesthetic required for a successful nerve block. (1) Indeed, the minimum effective volume for ultrasound (US)-guided supraclavicular block (SCB) has been recently studied and found to be 40 mL (MEAV95) using a combination of 2% lidocaine and 0.5% bupivacaine. (2)However, the minimum effective concentration required to produce a successful supraclavicular block is unkown . We hypothesize that effective surgical anesthesia can be achieved with dilute ropivacaine, i.e., a lower concentration than is commonly recommended, which could result in greater patient safety.

Inclusion criteria:

Patients that were ASA I-III, BMI< 35 and 18 years and above who presented for upper limb surgery not involving the shoulder were recruited.

Technique

All blocks were performed by 1 of 5 regional anesthesiologists with expertise in US-guided SCB block and who were blinded to the concentration of the local anesthetic.

Patients were sedated with midazolam and fentanyl to achieve anxiolysis while maintaining verbal contact. SCB were performed with the patient lying supine. A 22-gauge, 80 mm Touhy needle was inserted at the lateral border of the probe using an in-plane technique towards the “corner pocket” (3). 40 ml of LA was injected to achieve circumferential spread around the brachial plexus. Care was taken never to inject intraneurally as indicated by US evidence of nerve swelling or pain/pressure on injection. Nerve stimulation was not used. The first patient received a concentration of 0.5% ropivacaine. The ropivacaine concentration for the subsequent patient was determined by the anesthetic response of the previous patient. The concentration was adjusted upward (in the case of failure) or downward (in the case of success) by 0.05%.

Sensation to ice was tested by a blinded assessor in the median, ulnar, radial and musculocutaneous nerve distributions every 5 minutes. Block success was defined as complete loss of sensation to ice in all 4 nerve distributions within 30 minutes. These patients proceeded with surgery under monitored anesthetic care (MAC). The next patient would receive a lower concentration of ropivacaine by 0.05%. Any patients with sensation of cold (even if it was reduced) in any of the 4 distributions within 30 minutes were deemed unsuccessful. The next patient would receive a higher concentration of ropivacaine by 0.05%.

Results:

We applied Dixon and Massey's up-and-down statistics with small sample size, stopping the study at 4 data points after the first failure. (4) We completed 13 patients with the first failure at 0.1% ropivacaine. As such, our ED 50 was 0.107%; 95% CI (0.081,0.132) and the ED95 was found to be 0.138%.

All patients were followed up within 48 hours and sensation had returned to normal.

Conclusion:

40 ml of 0.138% ropivacaine is sufficient to produce surgical anesthesia in 95% of the population with US-guided SCB.

References:

1) Williams SR, Chouinard P, Arcand G, Harris P, Ruel M, Boudreault D, et al. Ultrasound guidance speeds execution and improves the quality of supraclavicular block. Anesth Analg. 2003;97:1518-1523.

2) Edel Duggan, MB, FCARCSI, Hossam El Beheiry, MB, BCh, PhD, FRCPC, Anahi Perlas, MD, FRCPC, Mario Lupu, MD, Alina Nuica, MD, Vincent W.S. Chan, MD, FRCPC, and Richard Brull, MD, FRCPC. Minimum Effective Volume of Local Anesthetic for Ultrasound-Guided Supraclavicular Brachial Plexus Block. Regional Anesthesia and Pain Medicine & Volume 34, Number 3, May-June 2009 34(3):215-8.

3) Soares LG, Brull R, Lai J, Chan VW. Eight ball, corner pocket the optimal needle position for ultrasound-guided supraclavicular block. Reg Anesth Pain Med. 2007;32:94-95.

4) Dixon WJ, Massey FJ. Introduction to Statistical Analysis. 4th ed. New York, NY: McGraw-Hill; 1983:377-394.

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SONIXGPS FOR ULTRASOUND-GUIDED BRACHIAL PLEXUS BLOCKS: A VALIDATION STUDY K. Umbarje, R. Tang, R. Randhawa, A. Sawka, H. Vaghadia Anesthesiology, Vancouver General Hospital, Vancouver, BC, Canada Introduction:

A limitation with current ultrasound technology is the difficulty of consistent needle tip visualization during block performance.We describe our experience with the SonixGPS™ system which provides a real-time display of the needle and tip using transmitters in the needle and transducer.

We present a cadaveric and clinical series of real-time ultrasound guided performance of interscalene, supraclavicular and infraclavicular brachial plexus blocks using an out-of-plane technique with the SonixGPS™ system.

Methods:

With institutional ethical approval, 3 unembalmed cadavers were selected.

Blocks in the Cadavers:

Interscalene, supraclavicular and infraclavicular blocks were performed bilaterally with methylene blue dye using an out of plane approach with 5-14 MHz Sonix GPS™ enabled linear transducer (Ultrasonix, Richmond, BC, Canada). All block were performed using a SonixGPS™ 19g 80mm needle utilizing the needle guidance system. At each site, 1 ml of methylene blue was injected at the target. A blinded anatomist then dissected each region layer by layer to confirm correct placement of dye along the brachial plexus. For each procedure the location of the needle tips were identified, spread of the dye noted and photographed.

Blocks in patients:

With written informed consent 15 patients were selected into each of 3 groups: interscalene (ISB), supraclavicular (SCB) and infraclavicular (ICB). Following the same techniques as on the cadavers, blocks were performed on the patients using local anesthetic. Patients were assessed for sensory and motor block every 5 minutes until complete blockade necessary for the proposed procedure was achieved. All patients were contacted afterwards for information on block resolution, complications and patient satisfaction.

Results:

In the cadaveric study, dissection confirmed the correct deposition of methylene blue around the brachial plexus in all 3 cadavers bilaterally for the ISB, SCB, and IFB.

In the clinical study, successful sensory blockade necessary for surgical anesthesia was achieved in all the patients. All the patients were pain free in the recovery and rated their satisfaction as very satisfied with the anesthetics. No complications were observed during the procedure nor reported during telephone follow up. In all the cases, the needle guidance system was easily aligned with the target structure and the calculated trajectory of the needle corresponded to the actual needle path at any angle.

Conclusion:

Successful nerve blockade is dependent on image acquisition and good visualization of needle tip position which is impaired at steep insertion angles. The SonixGPS™ system, with sensors in the probe and needle, allows for the accurate extrapolation of needle position relative to the ultrasound plane, regardless of angle. Successful blocks of the upper limb were achieved with an out-of-plane approach in all cadavers and patients

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IMPACT OF PERFORMING BREAST SURGERY WITH ULTRASOUND GUIDED PARAVERTEBRAL BLOCK WITH SEDATION VERSUS GENERAL ANESTHESIA K. Schroeder, M.P. Ford, J.M. Blake, B.M. Anderson, M.J. Donnelly Department of Anesthesiology, University of Wisconsin School of Medicine and Pub, Madison, WI, USA Introduction: Anesthetic technique can have a profound impact on the perioperative course of patients undergoing breast surgery. Previous research has demonstrated that a paravertebral block (PVB) for breast surgery can decrease postoperative pain with movement and at rest, areal distribution of pain, opioid consumption and nausea. Preincisional PVB has also been reported to decrease the incidence of chronic pain and cancer recurrence following breast surgery. Previous reports have focused on the benefit of traditional approaches to PVBs. Recent advances in ultrasound (US) imaging have allowed PVBs to be performed under US guidance. We hypothesized that US guidance would allow us to perform PVBs that would function well and allow us to perform simple breast surgery effectively with sedation alone. Methods: We performed a retrospective chart review of 300 consecutive patients presenting for breast surgery. Patients were then divided by surgical type resulting in 151 patients presenting for lumpectomy surgery. Of these patients, 27 patients received an US guided PVB with general anesthesia (GA), 116 received an US guided PVB with sedation (SED) and 8 patients received GA alone. US guided PVBs were typically performed at levels T1, 3, and 5 with 10 ml of either 0.5% ropivacaine or 0.5% bupivacaine injected at each level. GA was typically accomplished with IV propofol induction and inhalational maintenance. SED was typically provided with IV propofol +/- ketamine. Opioids were provided at the discretion of the anesthesia team caring for the patient. Via retrospective review, we examined multiple perioperative outcome measurements. Data analysis was accomplished with either a t-test or chi-squared test as appropriate. Results: Baseline patient characteristics were similar between different anesthesia technique groups (table 1). Patients in the block with SED group required unplanned conversion to GA in 6.9% of cases. PACU Phase I data was similar between the different anesthesia techniques likely secondary to 85.3% of block with SED patients bypassing PACU Phase I. PACU Phase II immediate, peak and mean pain scores were all significantly less in the block with SED group. Interestingly, PACU Phase II opioid consumption was significantly greater in the block with SED group compared to block with GA and GA alone. Rates of nausea in PACU Phase I and II were low and similar regardless of anesthetic technique. Hospital admission occurred much more frequently in those patients receiving a block with GA and in those with GA alone. In those patients requiring hospital admission following their outpatient breast surgery (18 in block with GA group and 18 in block with SED group), POD #1 nausea and 24 hour opioid consumption were similar(table 2). Discussion: Our results indicate that US guided PVBs can be effectively used to avoid GA. Our results also indicate that there may be substantial benefits to patients if GA is avoided in the setting of US guided PVBs. Given that this is a retrospective study, selection bias and varying intraoperative management strategies exist. Therefore, future randomized controlled studies that evaluate US guided PVBs are necessary

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A22

REAL-TIME ULTRASOUND GUIDED SUBARACHNOID BLOCK S. Patel, A. Lansdown, P. Conroy, P. McHardy, C. McCartney Anesthesia, Sunnybrook Health Sciences Centre, Toronto, ON, Canada INTRODUCTION

When performing spinal anesthesia accurate identification of the subarachnoid space is paramount. Complications such as paresthesia, dural puncture headache and infection, are associated with the puncture technique. Landmark based approaches may not take into account anatomical variations and frequently leads to incorrect identification of a given lumbar inter space.1

“Pre-puncture” ultrasound guided central neuraxial blockade has become a popular technique in recent years, allowing demonstration of anatomy and the appropriate insertion point for needle placement.

Real time ultrasound (RTUS) guided needle insertion for neuraxial block placement has already been shown for epidural 2. There has also been a series of 10 patients where RTUS guided subarachnoid block (SAB) has been successfully employed.3

METHODS

In our institution we have developed and refined a technique using RTUS. A series of 100 patients undergoing hip or knee surgery received SAB using a standard protocolized RTUS technique.

Data was collected and compared with a previous cohort of 100 patients where traditional landmark +/- pre-puncture ultra sound was used

RESULTS

Data was compared between the two groups (non-RTUS and RTUS) and analyzed for using Wilcoxon Rank Sum test. There were 2 patients in the RTUS group who required conversion to general anesthetic.

When comparing number of skin punctures to perform successful SAB no significant reduction was found when using RTUS, however there was a significant reduction in number of needle passes.

DISCUSSION

Despite its growing popularity the practice of pre-puncture ultrasound in neuraxial anesthesia is limited as the angle spinal needle is inserted may differ from that used at scanning. This may result in multiple needle insertions and/or passes.

Multiple attempts may lead to discomfort for the patient, block failure, and complications such as nerve injury, frustration for the anesthesiologist, and poor patient satisfaction. Multiple needle passes are an independent predictor of complications, such as inadvertent dural puncture, vascular puncture, and paresthesia. Elicitation of paresthesia has been shown to be a risk factor for persistent neurological deficit after spinal anesthesia. 4

This case series demonstrated that the use of a RTUS technique for performing SAB reduced the number of needle passes.

It must be noted that this study had a number of drawbacks. The two groups compared were unmatched. Techniques in the non-RTUS group were non standardized and no follow up data was collected

Despite these limitations this study suggests that a RTUS technique may have some value over other techniques. There is need for further validation and comparison with pre-puncture and landmark based techniques.

REFERENCES

1 Chin K, et al. Ultrasonography of the Adult Thorcic and Lumber Spine for Central Neuroaxial Blockade. Anesthesiol 2011; 114:1459 - 85 2 Karmakar, M wt al. Real-time ultrasound-guided paramedian epidural access: evaluation of a novel in-plane technique. BJA. 2009 845-854

3 Lee PJ et all. Real-Time Ultrasound-Guided Spinal Anesthesia Using Taylor's Approach. Anesth Analg. 2011 3

4 Chin et al, Ultrasound Imaging Facilitates Spinal Anesthesia in Adults with Difficult Surface Anatomic Landmarks. Anesthesiol 2011; 115: 1-8

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ULTRASOUND-GUIDED MID-FOREARM BLOCK OF RADIAL, ULNAR AND MEDIAN NERVES AS PRIMARY ANESTHETIC FOR HAND SURGERY V.H. Nguyen, A.M. Shilling, A. Morman, K. Beers Department of Anesthesiology, University of Virginia, Charlottesville, VA, USA Background and objectives: At the University of Virginia Medical Center, ultrasoundguided forearm blockade of the radial, ulnar and median nerve is routinely used for hand surgery distal to the radio carpal joints with tourniquet time less than 60 minutes. This retrospective case series looks at the analgesic and anesthetic effectiveness of this type of block.

Methods: We reviewed the anesthetic records of patients who received forearm blockade of the radial, ulnar and median nerve over a 9 month period. Our data collection included patient demographic, type of surgery, presence/duration of tourniquet, intra-operative anesthetic management, total anesthetic and analgesic drugs, and post-operative verbal rating scale (VRS) pain score. Analgesic block success was defined as documented lack of sensation over distribution of the blocked nerves resulting in VRS pain score of 0. Surgical block success was defined as usage of the block as the primary anesthetic without the need for general anesthesia (GA).

Results: We performed 32 ultrasound-guided forearm blocks. Blocks were used as the primary anesthetic in 84% of patients (27 out of 32). Of the five patients with blocks who received GA, four met the criteria of analgesic block. Analgesic block success rate was 91% (29 out of 32 patients). This rate increased to 97% if two patients with unplanned surgical involvement of the radio-carpal joints were excluded from analysis.

Conclusions: Ultrasound-guided forearm blocks of individual radial, ulnar and median nerve can be highly effective for hand surgery. They are most suitable for surgery distal to the radio-carpal joints with limited tourniquet time.

A24

INTERNATIONAL PUBLICATION TRENDS IN REGIONAL ANESTHESIA AND PAIN MEDICINE J. Groth, K.M. Schroeder Department of Anesthesiology, University of Wisconsin School of Medicine and Pub, Madison, WI, USA Introduction: Regional Anesthesia and Pain Medicine (published under the name Regional Anesthesia until 1998) has been in publication since 1976. The journal was originally distributed freely to all ASRA and ASA members. The first issue contained only ten pages and subsequent editions were published quarterly. From this humble beginning, Regional Anesthesia and Pain Medicine has evolved into a bi-monthly publication with an increasing impact factor and status within the anesthesia community. This study investigated the changing contributions to Regional Anesthesia and Pain Medicine throughout the years.

Methods: The journal Regional Anesthesia and Pain Medicine (formerly Regional Anesthesia) was reviewed at 5 year intervals between 1985 and 2010. For each primary research article contained within the journal, the country of origin of the first author was documented. Countries were then grouped into geographic regions (North America, South America, Europe, Asia, and Africa). Articles were assigned by one evaluator (JG) and primary research was grouped into five categories (animal studies, controlled clinical trial, laboratory, randomized control trial and other design).

Results: The USA has had a strong record of publication of primary research in Regional Anesthesia and Pain Medicine throughout the years. While the percentage of articles originating from the USA has remained high, it has decreased substantially from its high of nearly 70% in 1985 to 57% in 2010. Other countries with high rates of publication of primary research included Canada (6.9% of publications), France (5.1% of publications), Japan (3.7%), Finland (2.9%) and the Netherlands (2.9%). Canada experienced a large increase in the proportion of primary research publications increasing from 4.3% in 1985 to 14.9% of publications in 2010. When geographical regions are analyzed, North America (64.4%) and Europe (25.3%) dominate publication in Regional Anesthesia and Pain Medicine. Africa is the only populated continent without primary research representation in the time periods analyzed.

Discussion: Anesthesiologists interested in pain management are fortunate to have a quality publication like Regional Anesthesia and Pain Medicine to showcase high quality developments within the field. Our research demonstrates that publications originated from throughout the world with 31 nations represented in this sample. With the exception of a noticeable increase in publication of primary research originating from Canada, the contributions from the various nations and regions have remained relatively stable throughout the years. While this data does represent only snapshots in time over the last 25 years of publication of Regional Anesthesia and Pain Medicine, it does illustrate regional variations.

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A SELF-PAIRED COMPARISON OF PERIOPERATIVE OUTCOMES, PATIENT SATISFACTION AND INSTITUTIONAL COSTS WITH AND WITHOUT THE USE OF A CLINICAL PATHWAY IN PATIENTS UNDERGOING TOTAL KNEE ARTHROPLASTY A. Oviedo Baena, C. Duncan, J. Hebl, T. Horlocker, S. Moeschler, A. Hanssen Mayo Clinic, Rochester, MN, USA Introduction:

Total knee arthroplasty (TKA) is one of the most commonly performed surgical procedures in the USA with continued surgical growth expected until the year 2030.1 The use of clinical pathways has been shown to enhance the quality, improve the safety, and reduce the cost associated with joint replacement surgery.2 However, confounding variables often make comparison between clinical studies difficult. Therefore, the current investigation examines the impact of implementing a clinical pathway on perioperative outcomes, patient satisfaction, and institutional costs for patients undergoing TKA using a self-paired cohort study design to minimize the impact of confounding variables.

Methods:

After IRB approval, the medical records of patients >18 years that have undergone both a right and left TKA were retrospectively identified using the Mayo Clinic Total Joint Registry. Study inclusion was restricted to patients who underwent their first primary TKA without the use of the Mayo Clinic Total Joint Regional Anesthesia (TJRA) Clinical Pathway; and their second (contralateral) primary TKA with the use of the TJRA Clinical Pathway. Each patient functioned as their own matched control with regard to patient demographics, associated comorbidities, surgeon and surgical technique. The first primary TKA was performed using traditional surgical and anesthetic (non-TJRA) techniques. The contralateral TKA was performed using the TJRA Clinical Pathway.3 Patient outcomes (pain scores, opioid requirements, rehabilitation milestones, side- effects, perioperative complications), patient satisfaction surveys, and institutional direct medical costs were evaluated and compared for each surgical episode of care.

Results

Fifty-four patients were identified for study inclusion with an equal number of males (n=27) and females (n=27). Mean age at the time of surgery was 64.6 years for the first TKA and 69.2 years for the contralateral TKA.

PATIENT Outcomes: Patients undergoing their TKA with the Mayo Clinic TJRA Clinical Pathway had significantly better perioperative analgesia with lower verbal analog pain scores and lower opioid requirements during the first 48 hours (Table 1). TJRA patients also had significantly shorter hospital length-of-stays (TJRA 3.8 days vs. non-TJRA 4.4 days; P< 0.001). There were no differences in perioperative complications.

SURVEY Outcomes: Forty-five (83%) patients completed the patient satisfaction survey. Patients reported significantly less postoperative pain, less postoperative confusion, and an easier time participating in physical therapy sessions after their second (TJRA Clinical Pathway) TKA (Table 2). The majority of patients (60%) reported that they resumed their normal daily activities significantly sooner after their second TKA as well.

ECONOMIC Outcomes: Total direct medical costs were $956 lower when the TJRA Clinical Pathway was used during the surgical episode of care (P=0.02; 95% C.I. $233-$1785). The majority of the cost savings was found to be Medicare Part A supply costs (Table 3).

Conclusions: The development and implementation of a comprehensive clinical pathway that emphasizes peripheral nerve blockade may improve patient outcomes, enhance patient satisfaction, and reduce direct medical costs for patients undergoing TKA.

References

1. Kurtz S, et al. J Bone Joint Surg 2007;89:780.

2. Barbieri A, et al. BMC Med 2009;7:32.

3. Hebl JR, et al. Reg Anesth Pain Med 2008;33:510.

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[023_Table3] A26

A COMPARISON OF FEMORAL NERVE BLOCK, FEMORAL SCIATIC NERVE BLOCK AND INTRAJOINT INJECTION IN POSTOPERATIVE ANALGESIA AFTER TOTAL KNEE ARTHROPLASTY H. Pang, S.C. Hofmann Anesthesiology, University of Nebraska Medical Center, Omaha, NE, USA Background. Capacity to ambulate represents an important milestone in the recovery process after total knee arthroplasty (TKA). The purpose of this study was to determine the analgesic effect of two analgesic techniques and their impact on functional walking capacity as a measure of surgical recovery. Methods. Forty ASA II-III subjects undergoing TKA were enrolled in a randomized, doubleblind, single-centre study receiving 48 h postoperative analgesia with either periarticular infiltration of local anaesthetic (Group I) or continuous femoral nerve block (Group F). Breakthrough pain relief was achieved with patient- controlled analgesia (PCA) morphine. The main outcome was postoperative morphine consumption. Early (postoperative days 1-3) and late (6 weeks) functional walking capacity (2 and 6 min walk tests, 2MWT and 6MWT, respectively), degree of physical activity (CHAMPS), health-related quality of life (SF-12), and clinical indicators of knee function (WOMAC, Knee Society evaluation, and range of motion) were measured. Results. Patients in Group F used the PCA less (P¼0.02) to achieve adequate analgesia. Postoperative 2MWT was similar in both groups (P¼0.27). Six weeks after surgery, recovery of 6MWT, physical activity, and knee function were significantly improved in

Group F (P,0.05). Preoperative walking capacity, physical activity and early total walking time were the independent predictors of early recovery. Distance and time spent walking were the predictors of functional walking exercise capacity at 6 weeks after surgery. Conclusions. Femoral block is associated with lower opioid consumption and a better recovery at 6 weeks than periarticular infiltration. Early postoperative activity measures (2MWT and walking time) were proved to be possible indicators of knee function recovery at 6 weeks after surgery.

A27

TRANSVERSUS ABDOMINIS PLANE BLOCK: CAN TAP BLOCK SURVIVE THE CHALLENGE OF MULTIMODAL ANALGESIA? A SYSTEMATIC REVIEW F.W. Abdallah, R. Brull Anesthesia, University of Toronto, Toronto, ON, Canada Abstract

Background: The role of TAP block in providing postoperative analgesia in various surgeries remains unclear. Some trials indicated significant analgesic advantages to TAP block, while others simply found no benefit to it. The heterogeneity of surgical procedures studied, the diversity of surgery-specific regimens, and the components of multimodal analgesic regimens used in these trials contributed to the ambiguity surrounding the potential role of TAP block in postoperative analgesia. This systematic review examines whether incorporating TAP block into surgery-specific multimodal analgesic regimens is advantageous.

Methods: We performed a systematic search of MEDLINE, EMBASE, Excerpta Medica, and Cochrane Central Register of Controlled Clinical Trials (from January 2005 to June 2011) to identify randomized controlled trials comparing the effects of TAP block to placebo or systemic analgesia or any other analgesic modality on analgesic outcomes.

Results: Twenty intermediate to good quality randomized trials that included diverse surgical procedures were identified. When a multimodal regimen inclusive of neuraxial morphine was used, the role of TAP block in cesarean deliveries was confined to reduction of opioid-related side effects. Despite the paucity of trials examining its role in major abdominal surgeries as colorectal surgery and hepato-biliary procedures, TAP block seems to be of minor benefit when epidural analgesia is part of the analgesic regimen. Comparative trials involving other surgical procedures such as total abdominal hysterectomy, appendectomy, inguinal hernia repair, and laparoscopic cholecystectomy produced limited evidence supporting the incorporation of TAP block into the multimodal regimen or using it as a substitute of one of its components.

Conclusion: We were unable to definitively identify a benefit to TAP block in the context of modern multimodal analgesic practices. This review suggests that the role of TAP block in contemporary practice remains limited. Future research is needed to support this role of TAP block and to investigate its potential role as a second-line or rescue analgesic

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[025_Table1_5]

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POSTOPERATIVE PAIN CONTROL AND BLOCK SATISFACTION FOLLOWING BRACHIAL PLEXUS BLOCK FOR AMBULATORY SHOULDER SURGERY S.C. Haskins, R.L. Kahn, P.M. Shaw, S.C. Reid Anesthesiology, Hospital for Special Surgery, Anesthesiology, New York, New York, NY, USA Introduction

Brachial plexus block (BPB) provides better post-operative pain control compared to general anesthesia or suprascapular block for arthroscopic shoulder surgery. [1,2] There is limited data evaluating specific aspects of BPB and their correlation with post-operative pain and patient satisfaction.

Methods

After IRB approval, a prospective cohort trial was conducted on 100 patients undergoing ambulatory arthroscopic shoulder surgery under BPB. Exclusion criteria included the inability to speak English, ASA>3, age< 18, patients discharged directly to a rehab facility, and patients on regular opioid therapy (>7 days). Patients completed a survey on POD2 or early on POD3 using the internet (REDCap)[3] or via telephone. Post-operative pain was assessed using a numeric rating scale (0-10), and satisfaction with analgesia, block duration and pre-op education was measured using a Likert scale (1-5).

Results

In the 48 hours following surgery, moderate to severe pain (4-10) was relatively common for both SCB and ISB (at rest: SCB 42%, ISB 26%; with movement: SCB 84%, ISB 96%), but no difference in mod-severe pain was seen between ISB and SCB. Further, there was no significant difference in the average pain score between the two blocks at rest (SCB 3.4 ± 2.1 vs. ISB 3.2 ± 1.4, p=0.5) or with movement (SCB 5.8 ± 2.2 vs. ISB 5.9±2.1, p= 0.91), and no difference in average satisfaction with post-operative pain management (SCB 4.2 ± 0.7 vs. ISB 4.0± 0.6, p=0.89). Block duration was longer when a long acting local anesthetic was added to mepivacaine (Mep/Bup 12.9 ± 6.2 hr vs. Mep 9.6 ± 5.3 hr, p=0.02), but there was no difference in pain scores at rest or with movement, and no differences in patient satisfaction between these 2 groups. Education regarding the block and post-operative pain control was also calculated as a secondary outcome. There was no difference in patient satisfaction regarding the block education and post-op pain education (4.0±0.9 vs. 4.2±0.7, p=0.26). However, patients were significantly less aware of the expected duration of the block (3.4±1.4) than they were aware of how to treat pain once the block wore off (4.2±0.8, p< 0.001). Conclusion

The results suggest that there is no perceived difference in post-operative pain control and satisfaction based on the type of brachial plexus block (SCB vs ISB) following shoulder arthroscopy. SCB may be preferred, since it appears to have less effect on hemidiaphragm function. [4,5] Simply extending block duration by 3 hours didn't influence outcome; the effects of longer durations are unknown. Further study is needed to determine if improved pre-op education impacts patient satisfaction regarding block duration.

References

1. Hadzig et al. Anesth 2005; 102: 1001-7

2. Singelyn, F et al. Anesth Analg 2004; 99:589-92

3. Harris PA et al. J Biomed Inform 2009; 42:377-81

4. Renes, SH et al. RAPM 2009 34(6): 595-9

5. Neal JM et al. Anesth Analg 1998 86(6):1239-44

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[026_Table2] A29

THE ANALGESIC EFFICACY OF TRANSVERSUS ABDOMINIS PLANE (TAP) BLOCKADE IN DONOR SITE PAIN FOLLOWING FREE DIEP AND MS-TRAM BREAST RECONSTRUCTION: A PROSPECTIVE COHORT STUDY T. Zhong, K. Wong, H. Cheng, M. Ojha, C. Srinivas, S.A. McCluskey, H. Clarke, L. Jacks, S. Hofer University Health Network, University of Toronto, Toronto, Toronto, ON, Canada The Analgesic Efficacy of Transversus Abdominis Plane (TAP) blockade in donor site pain following Free DIEP and MS-TRAM breast reconstruction: A Prospective Cohort Study

Toni Zhong, MD, MHS, Karen Wong, MD, Homan Cheng, MD (Candidate) , Marie Ojha, MN, Coimbatore Srinivas, MD, Stuart A. McCluskey,MD, PhD, Hance Clarke, MSC, MD , Lindsay Jacks, MSc, Stefan O.P. Hofer, MD, PhD

Introduction:

Autologous breast reconstruction by free deep inferior epigastric perforators (DIEP) flap or free Muscle Sparing-Transverse Rectus Abdominis Myocutaneous (MS-TRAM) flap can cause significant postoperative pain at the abdominal donor site. The TAP block is an expanding regional anaesthesia technique that provides analgesia following major abdominal surgery1, 2, 3, and 4. The deposition of local anaesthetic between the internal oblique and transversus abdominis muscle layers can result in sensory blockade from T7 to L15. Our organization investigated the analgesic efficacy of intermittent TAP blockade in abdominal donor site pain in the first two postoperative days following autologous breast reconstructive surgery.

Material and methods:

Patients

Study Group (TAP block)

All patients undergoing microvascular breast reconstruction using the free MS-TRAM or DIEP flap techniques with two plastic surgeons (TZ, SH) were invited to participate in this study. Between June 12, 2010 and March 20, 2011 signed informed consent was obtained from 45 consecutive patients to undergo TAP catheter(s) insertion for the investigation of postoperative analgesic control. Intraoperatively, a multi-orifice epidural catheter was inserted under direct vision into the TAP. Then 10 mLs of 0.25% bupivacaine was injected into each TAP catheter every 12 hours until removal on the morning of postoperative day 3.

Control Group (No TAP block)

The control group was composed of a retrospective cohort of 80 consecutive patients who underwent free MS-TRAM or DIEP flap breast reconstruction with the same two plastic surgeons between January 9, 2009 and May 20, 2010. This group was selected since they were temporally closest to the TAP block group.

Postoperatively, both groups had intravenous (IV) patient controlled analgesia (PCA) for the first 48 hours after surgery. The primary outcome measured in the study was IV-PCA consumption in the first 48 hours.

In both groups, patients were excluded from analysis if they had a body mass index greater than 40, history of chronic pain with daily opioid use greater than 50mg of oral morphine or equivalent, or if they had a major postoperative complication requiring a second surgery.

Results

There were no complications associated with using TAP catheters and the delivery of intermittent anaesthetic blockade. The 48-hour IV PCA delivered opioid requirement was significantly less (p< 0.001) in the TAP block group (17.10 +/-17.23 mg IV morphine equivalent) compared to the control group (48.44 +/-39.53 mg). When self-reported pain scores at rest were compared, it was found that the median pain scores on each postoperative day was lower in the TAP block group than control group, although not statistically significant. Median self-reported pain scores with movement was reduced for the TAP block group and approached statistical significance (p=0.07) on postoperative day 2.

Conclusion

Intermittent delivery of 0.25% bupivacaine through the TAP significantly reduced parenteral opioid requirements in the first two postoperative days following MS-TRAM or DIEP flap reconstruction of the breast. Donor site abdominal pain was reduced in the TAP block group, however did not reach statistical significance.

References

1. Carney J, McDonnell JG, Ochana A, et al: The transversus abdominus plane block provides effective postoperative analgesia in patients undergoing total abdominal hysterectomy. Anaesth Analg 107:2056, 2008

2. Petersen PL, Mathiesen O, Torup H, et al: The transversus abdominis plane block: A valuable option for postoperative analgesia? A topical review. Acta Anaesthesiologica Scandinavica 54:529-535, 2010

3. McDonnell JG, Curley G, Carney J, et al: The analgesic efficacy of transversus abdominis plane block after cesarean delivery: A randomized controlled trial. Anesthesia and Analgesia 106:186-191, 2008

4. Niraj G, Searle A, Mathews M, et al: Analgesic efficacy of ultrasound-guided transversus abdominis plane block in patients undergoing open appendicectomy. British Journal of Anaesthesia 103:601-5, 2009

5. Mukhtar, K. Transversus abdominis plane (TAP) block. The Journal of New York School of Regional Anesthesia, 12, 28-33, 2009.

[029_Table1] A30

INTEGRATED ANALYSIS OF EFFICACY AND SAFETY OF A ONCE-DAILY GASTRORETENTIVE FORMULATION OF GABAPENTIN IN PATIENTS WITH POSTHERPETIC NEURALGIA M. Milane Depomed, Inc., Menlo Park, CA, USA Background: The immediate-release formulation of gabapentin (gabapentin TID) is approved for treatment of postherpetic neuralgia (PHN). Although gabapentin TID has a low propensity for drug-drug interactions, it requires multiple daily dosing and is associated with a high frequency of dizziness and somnolence. A once-daily gastroretentive formulation of gabapentin (G-QD) has been approved for the management of PHN. The G-QD formulation employs gastroretentive technology to provide prolonged and gradual release of gabapentin to its site of absorption in the proximal small intestine.

Methods: Integrated analyses were performed on two controlled PHN studies including 333 patients randomized to receive 1800 mg G-QD gastroretentive gabapentin and 340 to receive placebo with the evening meal. The primary efficacy assessment was the change in “average pain for the past 24 hours” Numeric Pain Rating Scale (NPRS) score, recorded every morning, from Baseline to Week 10. Secondary efficacy assessments included Patient Global Impression of Change (PGIC) at Week 10 and change in average daily sleep interference score (SIS) from Baseline to Week 10. An Institutional Review Board approved both protocols.

Results: The mean absolute last observation carried forward (LOCF) change in NPRS score was significantly greater with G-QD than with placebo (−2.3 vs. −1.8; p=0.001). A greater proportion of G-QD patients achieved a ≥50% response compared with placebo (35.7% vs. 25.4%; p=0.003). At Week 10, significantly more G-QD patients felt very much/much improved compared with placebo (42.3% vs. 30.3%; p=0.001) and the mean absolute LOCF change in SIS was significantly greater with G-QD than with placebo (−2.6 vs. −1.8; p< 0.001). G-QD was generally well tolerated; 96.4% of patients taking G-QD completed the titration period; 83.6% completed the study. Dizziness (10.9%) and somnolence (4.5%) were the most common adverse events.

Conclusions: G-QD can be an effective, well tolerated treatment option for PHN.

A31

OUTPATIENT MANAGEMENT OF CONTINUOUS PERIPHERAL NERVE CATHETERS FOLLOWING ORTHOPEDIC SURGERY: A RETROSPECTIVE REVIEW OF EXPERIENCE OF A UNIVERSITY-BASED TEACHING HOSPITAL J.R. Bracken, M.L. De Ruyter, M.A. Rockford, G. Horton Anesthesiology, University of Kansas Medical Center, Orthopedic Surgery, Kansas City, KS, USA Introduction: Continuous peripheral nerve block (CPNB) can provide satisfactory analgesia for multiple days following many orthopedic procedures (1). While successes have been reported (2), CPNB is less commonly used for outpatient surgical patients. One may hypothesize that this is primarily because of concerns regarding catheter related complications, difficulty providing adequate physician-access to patients outside of the hospital, and the potential impact on the anesthesiologist managing CPNB care for outpatients. We present the findings on 510 consecutive outpatients who were treated at our institution with CPNB over a three-year period. Methods: Between 1/1/08 and 10/31/11 adult patients undergoing foot and ankle surgery were offered a home CPNB analgesic therapy. Following consent, preoperatively the anesthesiology physician placed a popliteal non- stimulating catheter employing a nerve stimulation technique or ultrasound guidance. 30 ml 0.5% ropivacaine was injected followed by catheter insertion. Patients received general anesthesia. In PACU, the block was assessed and a continuous infusion of 0.2% ropivacaine was initiated. At discharge, an anesthesiologist assessed the surgical pain and if adequately controlled initiated the home CPNB (500 ml 0.2% ropivacaine, 5ml/hr with 5 ml/h patient bolus, On-Q Pump®, Iflow Corp, Lake Forrest, CA) and discussed in detail the written instructions with the patient. Patients were provided telephone access to an on-call anesthesiologist during the postoperative period. The anesthesiologist contacted each patient daily while the CPNB was in place to assess the efficacy and safety of the block. These results were analyzed retrospectively following IRB approval. Results: Of the 510 patients, 40 (7.8%) patients were lost to follow-up. The average duration of catheter infusion of 2.3 days. Beyond the protocol of daily calls by the anesthesiologist, 9 (1.7%) patients additionally accessed the on-call anesthesiologist. Four patients visited their local ER related to pain and/or CPNB malfunction (0.8%). Other complications included symptoms concerning for local anesthetic toxicity (metallic taste) occurred in 3 (0.5%), 1 local site infection (0.2%), and 1 patient reported hives (0.2%). No patients reported falls or difficulty in removing their home PNC. Discussion: Discharging patients with lower extremity blocks remains controversial as adverse events, such as falls, have been reported with ambulatory femoral nerve CPNB (3). Our series is a unique report of 470 outpatients treated with popliteal CPNB following orthopedic surgery. We observed few CPNB-related complications. Once daily telephone contact with patients was adequate, there was minimal impact on the anesthesiology care team, and patients or caregivers were able to reliably remove their catheters at home. This review suggests that with adequate discharge instructions and telephone access to physicians, patients can easily and reliably manage CPNB in the outpatient setting with minimal risks and little impact on the anesthesiologist. Reference:

1. Anesth Analg 113(4):904-925, 2011

2. Anesthesiology 97(4):959-965, 2002

3. Anesthesiology Clin 29:193-211, 2011

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ULTRASOUND GUIDED BRACHIAL PLEXUS BLOCK: THE ONSET OF SENSORY BLOCKADE IS FASTER AFTER AN AXILLARY APPROACH THAN WITH THE SUPRACLAVICULAR APPROACH M. Karmakar, S. Winnie, K. Wing-Hong, J. LI Anaesthesia and Intensive Care, Hong Kong, The Chinese University of Hong Kong, Hong kong, The Chinese University of Hong Kong, Hong Kong, Hong Kong S.A.R. Background: Ultrasound (US) guidance results in faster onset of sensory and motor blockade after brachial plexus block (BPB).1 Currently there are limited data comparing block dynamics after different US guided (USG) BPB techniques. We hypothesized that an axillary approach would produce faster onset of BPB than a supraclavicular approach. Method: After ethical approval and written informed consent, 31 patients scheduled for elective hand surgery were randomized to receive either an USG axillary (n=15) or a supraclavicular (n=16) BPB. All the USG BPB's were performed by a single investigator using a Philips HD11XE ultrasound system and ropivacaine 0.5% (plain, total volume 20 ml). The USG axillary BPB was performed using a multiple injection technique previously described.2 In the USG supraclavicular BPB group the local anesthetic was injected posterior to the subclavian artery after eliciting a distal motor response in the hand using nerve stimulation.3 The end of local anesthetic injection was defined as the time when the BPB was completed (time = 0). Loss of sensation to cold (ice) in the cutaneous distribution of the median, ulnar, radial and musculocutaneous nerves in the forearm and hand was assessed by a research nurse at regular intervals (5 min, 10 min, 20 min, and 30 min) after the block using a verbal rating scale (VRS, 100 = normal sensation to 0 = no sensation). Motor blockade of each individual nerve in the anesthetized upper extremity was tested using a 3-point scale: 0 = normal movement and power, 1 = motor weakness or paresis, and 2 = paralysis. Success of the block was defined as the absence of cold sensation 30 minutes after the block. An overall sensory score was also calculated, for each patient, by averaging the VRS in the distribution of the four nerves. Onset of sensory block (onset time) was defined as a 70% reduction (VRS ≤ 30) in sensation to cold.4 Independent samples t-test or Mann-Whitney U test were used for statistical comparison. A p value < 0.05 was considered statistically significant. Results: The USG BPB was successful and it was effective for surgical anesthesia in all the patients studied. The mean VRS for loss of sensation to cold in the distribution of the median, radial and ulnar nerves was significantly lower (p≤0.05) in the axillary group (Fig 1). Onset of sensory block in the distribution of the median (p=0.03), radial (p=0.01) and all the four nerves considered together (i.e. the overall onset time, p=0.006) was also significantly faster in the axillary group compared to the supraclavicular group (Table 1). There were more patients [n (%)] in the axillary group with a VRS ≤ 30 at 5 minutes [axillary, 12 (80%) and supraclavicular, 4 (25%), p=0.002] and 10 minutes [axillary, 15 (100%) and supraclavicular, 11 (69%), p=0.04] after the BPB. There was no difference in motor blockade between the study groups (data not provided). Conclusion: During ultrasound guided brachial plexus block the onset of sensory blockade is faster after an axillary approach than with the supraclavicular approach. References 1.Abrahams MS et al.BJA 2009;102:408-17 2.Casati A et al. Anesthesiology 2007;106: 992-6 3.Chan VWS et al. Anesth Analg 2003;97: 1514-7 4.Marhofer P et al. Anesth Analg 1997;85: 854-7

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EFFECTS OF A PAIN SERVICE ON PAIN SCORES IN SELECTED ORTHOPEDIC PATIENTS V. Mihaela, K. Boretsky, A. Chen, J. Roach, A. Cassara, F. Cladis, K. Boretsky Childrens Hospital of UPMC, pittsburgh, University of Pittsburgh Medical Center, Pittsburg, University of Pittsburgh Medical Center, pittsburgh, PA, USA Introduction: Orthopedic procedures are among the most painful surgeries performed in Pediatric Hospitals. Traditionally, most orthopedic postoperative pain was managed by the sole administration of narcotic analgesics. Twelve months ago, the Childrens Hospital of Pittsburgh implemented a dedicated perioperative pain service for the performance of interventional nerve blocks to decrease the amount of pain experienced by children in the postoperative period. Optimal pain control is crucial as it can result in less suffering, fewer psychological sequellae, shorter hospital stays, more rapid return to activities of daily living, and lower incidence of the development of chronic pain. It is hypothesized that a pain service with the ability to perform nerve blocks as a component of multimodal techniques will improve pain related outcomes in pediatric patients.

Methods: The investigators conducted a retrospective chart review of 80 patients who had undergone pelvic and femoral osteotomies and hip reconstructive procedures from August 1, 2006 through September 19, 2011 and compared outcomes to age matched, procedure matched groups with and without nerve block catheters (40 in each group). The following data were collected: pain scores, length of stay, opioid consumption in morphine equivalents, time to first opioid administration, antiemetic consumption, heart rate, and details of infusions of local anesthetics if used.

Results: The results are shown in figures 1-3. Pediatric patients who had continuous lower extremity nerve block catheters used less narcotic analgesic medications in the first 24 hours (0.28 vs. 0.57 mg/kg), had a longer time to administration of the first rescue pain medication (292 vs. 81 minutes) and had a reduced need for antiemetic rescue (23 vs. 11 total doses) compared to children who received only narcotic analgesics. There was no difference in pain scores, heart rate, or length of hospital stay.

Discussion: The use of regional anesthesia in infants and children has increased dramatically over the past 30 years as a means of treating pain. It has been unclear what impact the implementaion of a pain service with expertise in this area may have on patient pain outcomes. This study demonstrates less opiod use, and less use of antiemetics which can be a surrogate marker for nausea and vomiting. Studies show that better pain management and less nausea and vomiting improves patient rehabilitation and patient satisfaction.

Conclusion: The addition of a pediatric acute perioperative pain service that can offer continuous perineural lower extremity catheters results in lower opioid consumption and decreased use of antiemetics.

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A PROSPECTIVE RANDOMIZED CONTROLLED TRIAL COMPARING THE EFFICACY AND SAFETY OF DEXMEDETOMIDINE VERSUS PROPOFOL TIVA IN CONJUNCTION WITH REGIONAL BLOCK FOR SHOULDER SURGERY IN BEACH CHAIR SITTING POSITION O.M. Wellisch, M. Kronenfeld, D. Saberito, M. Pagala, J. Choueka, P. Gupta Maimonides Medical Center, Brooklyn, NY, Maimonides Medical Center, Brooklyn, NH, Anesthesiology, Brooklyn, NY, USA Introduction: Operative shoulder arthroscopy in beach-chair sitting position presents with airway management and hemodynamic challenges. Regional techniques are especially useful in patients for whom airway instrumentation and endotracheal intubation is undesired. Dexmedetomidine (DEX) has been shown to simulate natural sleep with minimal respiratory depression, and is widely used for total intravenous anesthesia (TIVA). Nevertheless, evidence of profound bradycardia and hypotension have limited its utility, particularly in the settings of hypovolemia, DM, chronic HTN, heart block, ventricular dysfunction and in the elderly, as well as, in surgery performed in the head-up or sitting positions. We set out to compare intra- and post-op hemodynamics, adequacy of anesthesia as well as requirement for airway intervention and supplemental anesthetics using DEX versus propofol based TIVA in conjunction with interscalene brachial plexus block for shoulder surgery in beach chair sitting position. We also assessed whether the type of anesthetic agent accounted for other differences in intra- and post-op outcome measures. Methods: This was a prospective randomized controlled trial. Fifty patients for shoulder arthroscopy in beach chair sitting position were randomly assigned into 2 groups to receive DEX or propofol TIVA. All pts received interscalene brachial plexus block preop. Standard ASA monitors and BIS were applied. Nasal cannula (2 l/min) provided capnographic monitoring. DEX bolus (1 mcg/kg over 10 min) was given during positioning with subsequent maint infusion (0.7-1.0 mcg/kg/hr). Propofol was titrated to effect (50-150 mcg/kg/min). IV Midazolam 0.5 mg was dosed at beginning of case and every 30 min as needed. We analyzed for demographics, anthropometric data, and incidence of hypoxia (SpO2< 93), hypotension (SBP< 90), profound bradycardia (HR< 45) and apnea (< 10 sec) as well as post-op parameters. Results: Demographics, anthropometric data (Table 1) and ASA class distribution (Table 2) did not differ significantly between the two groups. Pts in DEX group received significantly less fentanyl IV (53.6 vs 75.0, p< 0.05) during preop nerve blockade. There was a non- statistically significant trend towards DEX group receiving more intraop midazolam IV (1.89 vs. 2.69 mg, P=0.067). There were no significant differences in volume of local anesthetic or incidence of respiratory or hemodynamic instability both intra- or post-op. Intraop awareness, time in PACU, PONV and post-op pain did not differ significantly between the groups. Discussion: In our hands, DEX failed to elicit any profound hemodynamic changes while providing a particularly favorable respiratory profile. Therefore, we propose the use of DEX in conjunction with regional blockade in sitting position as a viable anesthetic option in patients with difficult airway presenting for shoulder surgery. Interestingly, our results also demonstrate no significant residual sedation with DEX as compared with propofol, even as a trend exists towards more liberal dosing of midazolam in the DEX group. Taken together, our results demonstrate safe and effective anesthesia with DEX in conjunction with regional blockade in the sitting position without any effect on post-operative parameters.

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ANATOMIC STUDY TO ASSIST IN ANKLE BLOCKS P. Ryan, H.T. Benzon, K. Mark, E.(. Yaghmour Northwestern University Feinberg School of Medicin, Anesthesiology, Chicago, IL, USA Background: The relationship of blood vessels and nerves being blocked for surgery of the foot is not definitely known. In blocking the saphenous nerve, a paravenous technique was described wherein local anesthetic was injected on both sides of the saphenous vein (1). Injection “anterior and posterior” to the vein is being recommended for blockade of the saphenous nerve just cephalad to the medial malleolus. Injection “circumferentially around” the short saphenous vein has been recommended for blockade of the sural nerve cephalad to the lateral malleolus (2). In a study, the deep peroneal nerve was noted to be lateral and anterolateral to the anterior tibial artery (3). In this study, we looked at the relationship of the saphenous, sural, and deep peroneal nerves to blood vessels.

Methods: We looked at atlases and recorded the following relationships: a) saphenous nerve and long saphenous vein distal to patella; b) saphenous nerve and long saphenous vein proximal to medial malleolus; c) sural nerve and short saphenous vein at the level of lateral malleolus; d) deep peroneal nerve and anterior tibial artery at the level of malleoli. We dissected 14 lower extremities of cadavers and looked at the stated anatomical relationships and noted the level where the posterior tibial, deep peroneal, and superficial peroneal nerves branch off, in relation to the malleoli.

Results: Three of 4 books noted the saphenous nerve to be posterior to saphenous vein below the patella (4-7). Proximal to the medial malleolus, the saphenous nerve was either anterior (4,6,7) or posterior (5) to long saphenous vein (4-7). Just cephalad to lateral malleolus, the sural nerve was noted to be either anterior (4-6) or posterior (5,7) to short saphenous vein. At the level of malleoli, the deep peroneal nerve was noted to be lateral to anterior tibial nerve (4-7). The level where the superficial peroneal nerve branches off, in relation to the malleoli, was either proximal (4,5,7) or distal (6) to malleoli. Our cadaver studies showed the following: a) below patella: saphenous nerve was posterior to vein; b) above medial malleolus: saphenous nerve runs alongside but posterior to long saphenous vein, occasionally there were branches of the vein that surrounded the nerve; c) proximal to lateral malleolus: sural nerve runs alongside posterior to short saphenous vein; d) level of lateral malleolus: nerve posterior/deeper and immediately behind vein, branches of vein occasionally wraps around nerve ; e) level of malleoli: deep peroneal nerve was lateral artery; f) posterior tibial nerve branched off up to 5 cm proximal, at level of, and 1 cm distal to medial malleolus; g) deep peroneal nerve branched off at level of malleoli; f) superficial peroneal nerve was superficial and branched off 1-12 cm proximal to level of malleoli.

Discussion: The lack of uniformity among atlases explains the injection of the local anesthetic on both sides of the blood vessel in ultrasound-guided blocks (1-3). The occurrence of venous plexuses around the sural and saphenous nerves at the level of the malleoli is the rationale for the recommendation of injecting local anesthetic around the vein when these nerves (2,3). The relationship between the deep peroneal nerve and artery was used as basis for deep peroneal nerve blocks (3,8). The proximal branching of the posterior tibial nerve is the basis for the recommendation of blocking the nerve 5-7 cm proximal to the medial malleolus (9).The superficial peroneal nerve should be blocked proximal to the level of the malleoli.

References: 1. De May JC. Reg Anesth Pain Med 26:504-506, 2001 2. Redborg KE. Reg Anesth Pain Med 2009;34:24-28

3. Antonakakis JG. Reg Anesth Pain Med 2010;35:217-221 4. Gray H, et al. Gray´s Anatomy. 2005:1480-1525, 5.Abrahams PH. McMinns Color Atlas of Human Anatomy. 2003:329-347. 6. Rohen J. Color Atlas of Anatomy. 1998:470-483. 7. Putz R. Atlas of Human Anatomy. 1997:362-372 8. Benzon HT. Anesth Analg 2009;109;2022-2024 9. Doty, R. Anesth Analg 2006;103:1300-5

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CURRENT STATUS OF RESIDENT EDUCATION AND CONFIDENCE LEVEL IN PERIPHERAL NERVE BLOCKS: A NATIONWIDE SURVEY OF GRADUATING ANESTHESIA RESIDENTS T. Sun, E. Lim, S. Kinjo Purdue University, West Lafayette, IN, UCSF, San Francisco, CA, USA Background and objectives: Peripheral nerve blocks have gained popularity over the past fifteen years due to advantages such as avoidance of airway manipulation, sparing of opioid side effects, and superior postoperative pain control. Accordingly, resident education and exposure to peripheral nerve blockade has increased and has been enhanced by advancements in technology and techniques. The Accreditation Council for Graduate Medical Education (ACGME) requires that residents perform forty peripheral nerve blocks by graduation. However, many educators have argued that this may not be adequate for competency. The aim of this nationwide on-line survey was to assess the level of exposure and confidence that graduating residents have with selected peripheral nerve blocks.

Methods: Program directors of all one hundred and thirty ACGME-accredited anesthesiology programs were contacted by email and asked to distribute an on-line survey link to residents in the CA-3 class. Information was gathered on the total number of each type of nerve block performed, technique(s) utilized, perceived comfort level in performing nerve blocks independently upon graduation from residency, perceived quality of regional anesthesia teaching during residency, and suggested areas for improvement.

Results: One hundred and seven residents from across the USA completed the survey. Almost all residents (91%) met the ACGME requirement for at least forty peripheral nerve blocks. Additionally, 74% performed over sixty blocks. Femoral and interscalene blocks were the two most frequently performed blocks, with 59% and 41% of residents performing more than twenty of each, respectively (Table 1). Most residents reported that upon graduation from residency, they would feel "very comfortable" independently performing interscalene, femoral, and popliteal blocks but not axillary, sciatic, or lumbar plexus blocks (Table 2). The vast majority of peripheral nerve blocks were done with ultrasound guidance and/or nerve stimulation (Figure 1). Overall, 79% of graduating residents were "mostly" to "very" satisfied with the quality of education received on peripheral nerve blocks during residency, leaving 9% of residents "somewhat satisfied" and another 12% who were "not satisfied."

Conclusions: Resident experience with peripheral nerve blocks has grown immensely in the last decade. Accordingly, the confidence level of graduating residents has increased dramatically and more anesthesia providers will be equipped to provide these services to their patients. Although most residents meet the ACGME requirement for forty peripheral nerve blocks, many do not feel competent in performing certain blocks upon completion of residency. Increasing resident exposure to peripheral nerve blockade through dedicated regional anesthesia rotations, as well as incorporating simulation and more didactic lectures, will further increase the confidence and competence of residents.

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IMPACT OF CYP2D6 AND CYP3A4 INDUCERS, INHIBITORS, AND SUBSTRATES ON URINARY HYDROCODONE AND METABOLITE MOLE FRACTIONS IN PATIENTS WITH PAIN N.H. Barakat, R.S. Atayee, J.D. Ma, B.M. Best, A.J. Pesce University of California, University of California, San Diego, Skaggs School, San Antonio Military Medical CenterDiego, Millennium Research Institute, San Diego, CA, USA Background: Hydrocodone combined with acetaminophen is commonly used for moderate pain. Hydrocodone is metabolized by cytochrome P450 (CYP) 2D6 into hydromorphone and by CYP3A4 into norhydrocodone. The study objective was to evaluate the effect of CYP2D6 and CYP3A4 inducers, inhibitors, and substrates on hydrocodone metabolism in patients with pain. Method: This was a retrospective analysis of urinary excretion data from specimens collected during routine office visits and analyzed at Millennium Laboratories by LC- MS/MS. IRB-exempt status was granted by the UCSD Human Research Protection Program. Two-sample t-tests and graphical analyses were conducted on first and single visits. Analyses compared hydrocodone metabolite mole fractions in the presence of CYP2D6 and CYP3A4 inducers, inhibitors, and substrates. Results: Hydromorphone mole fractions in the presence of CYP2D6 inducers (n=14) did not change (~1%, p>0.05) however, with CYP3A4 inducers (n = 1472) it decreased (16%, p< 0.00001). Hydromorphone mole fractions decreased in the presence of CYP2D6 inhibitors (50%, p< 0.00001) and substrates (16%, p< 0.00001). Norhydrocodone mole fractions increased in the presence of CYP2D6 inhibitors (10%, p< 0.00001) and decreased in the presence of CYP3A4 inhibitors (15%, p< 0.00001). Norhydrocodone mole fractions in the presence of CYP2D6 and CYP3A4 inducers significantly increased (10%, p< 0.00001). Conclusion: The mole fraction of the metabolites, hydromorphone and norhydrocodone, increased in the presence of CYP 2D6 and/or CYP 3A4 inducers and decreased with enzyme inhibitors. Furthermore, the presence of CYP2D6 substrate also increased the mole fraction of hydromorphone suggesting pathway saturation. Detecting CYP2D6 and CYP3A4-mediated drug-drug interactions are possible with urinary hydrocodone metabolites.

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STEADY STATE PHARMACOKINETICS (PK) OF BUPIVACAINE FOLLOWING CONTINUOUS FEMORAL NERVE CATHETER PLACEMENT IN CHILDREN AND ADOLESCENTS UNDERGOING ACL REPAIR: A SIMPLE 'FINGER STICK' TECHNIQUE! S. Suresh, A. Cambic, J. Galinkin, M. Logan, Y. Asher Children's Memorial Hospital, Chicago, IL, Children's Hospital Colorado, Aurora, CO, Anesthesiology, Chicago, IL, USA Aim: The aim of this study was to determine the pharmacokinetics of bupivacaine following nerve blocks and continuous femoral nerve catheter infusions for adolescents undergoing ACL reconstructive surgery.

Methods: After IRB approval, as well as parental permission and adolescent assent, were obtained, 5 adolescents undergoing ACL reconstructive surgery were enrolled in the study. After induction of general anesthesia, femoral and popliteal nerve blocks under ultrasound guidance, using bupivacaine 0.25% before the commencement of surgery were placed by one of the authors (AC, SS, YA). The dose of bupivacaine administered was based on the weight of the patient and approximately 0.3 mL/kg not to exceed 20 mL for each individual injection, followed by a femoral nerve catheter with continuous infusion of 4 mL/hr of 0.1% bupivacaine that was initiated in the post anesthesia care unit (PACU).. Whole blood samples were collected on a piece of Whatman Protein Saver 903 filter paper from a peripheral venous line at baseline, 5, 15, 30, 60, 120, 240 minutes by one of the authors (AC, YA, ML) and at home by the patient with simple finger stick at 24 hours and 48 hours. Subjects were considered evaluable if they had a total of 5 samples collected. The extract from the dried blood samples (DBS) collected on the Whatman Protein Saver 903 filter paper were analysed using a LC-MS/MS system in combination with online extraction at a lab based in Denver Childrens Hospital under the supervision of one of the authors (JG). The analyte was detected using the mixed reaction mode (MRM).

Results: We have been able to collect samples from 5 adolescents at the time of this abstract submission, and we plan on collecting data on a total of 10 patients. There were 4 males; 2 females; the mean age of the patients was 16 years. The mean maximum concentration noted was 135ng/ml with a range of 104-180ng/mL. The steady state level of bupivacaine during continuous nerve block infusion was 80.5ng/ml. These are well below published toxic levels and aligned with the concentrations of bupivacaine in other blocks including caudal and peripheral nerve blocks previously published. No adverse effects were noted with the performance of the blocks.

Discussion: This is, to our knowledge, the first report looking at the steady state pK of bupivacaine in children and adolescents, with continuous femoral nerve catheters. It is important that the bupivacaine levels be below toxic levels particularly when used in the catheters as these patients are using them at home, away from direct medical supervision. A novel method using a simple finger stick technique at home was utilized in this cohort.

REFERENCES

1. Antimicrob Agents Chemother. 2007; 51:2668-73

2. Anesth Analg. 2010; 1 10(2):630-4.

3. J Chromatogr B Biomed Sci Appl. 2000; 748:41-53.

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EFFECTIVENESS OF COMPUTER-BASED VIDEO AND SIMULATION IN ULTRASOUND-GUIDED REGIONAL ANESTHESIA TRAINING G. Woodworth, E. Chen, J.-L. Horn 1Oregon Health & Science University, Oregon Health & Science University, Portland, OR, USA Background: The recent surge in ultrasound (US) guided regional anesthesia brings into question how to effectively educate anesthesia providers and adequately assess knowledge and skills. The purpose of this prospective, randomized study sought to determine the effectiveness of a short educational video and simulation to teach key anatomic relationships and improve US image acquisition and interpretation, as well as determine whether a written knowledge test and a live US scanning test would be valid assessment tools for US guided regional anesthesia skills.

Methods: Twenty-eight anesthesia residents, fellows, and community anesthesiologists with varied ultrasound experience were randomized to teaching video with interactive simulation or sham video groups. Participants were assessed pre and post-educational video and simulation on their ability to identify the sciatic nerve and other anatomic structures on static US images, as well as their ability to locate the sciatic nerve with US on live models.

Results: Pretest written test scores correlated with reported ultrasound block experience and with live US scanning scores (Kendall´s Tau = 0.47 and 0.62, respectively). The teaching video and simulation significantly improved scores on the written exam compared to the control group (p< 0.001); however, it did not significantly improve live US scanning scores.

Conclusions: A short educational video with interactive simulation significantly improved knowledge of US anatomy in the sciatic region, but failed to improve hands-on performance of ultrasound scanning to localize the nerve. This provides further evidence that simple educational tools that can be delivered over the Internet can impart explicit knowledge, but may by insufficient to significantly improve technical skills. It also provides preliminary data on the validity of written and live scanning tests for assessment of ultrasound image acquisition and interpretation skills.

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PREOPERATIVE ULTRASOUND FINDINGS IN PATIENTS UNDERGOING BRACHIAL PLEXUS REPAIR R.R. Johnathan, S. Clendenen Mayo Clinic Florida, Jacksonville, FL, USA Preoperative Ultrasound Findings in Patients Undergoing Brachial Plexus Repair

Background: The utility of ultrasound for performing brachial plexus blocks has been well established. The objective of this investigation was to apply this imaging modality for preoperative surgical planning and explore interesting sonographic findings in patients that have experienced various brachial plexus injuries.

Methods: The authors performed transcutaneous ultrasound of five patients in the holding area prior to undergoing brachial plexus repair. Both the operative and nonoperative sides were imaged and the findings shared with the surgical team.

Results: One patient sustained preganglionic C5, 6, 7 nerve root avulsions and ultrasound demonstrated a pseudomeningocele in the proximal brachial plexus region (Image 1) where these nerve roots would be expected. The absence of these nerve roots was confirmed intraoperative as the initial supraclavicular incision did not isolate the nerve roots and a second, infraclavicular incision had to be performed to locate these damaged nerve endings which had migrated distally. Of the three patients that sustained postganglionic nerve injuries, ultrasound demonstrated the C5,6,7 nerve roots and did not reveal significantly altered anatomy. The transverse cervical artery was easily identified with color Doppler (Image 2) in these patients. One patient underwent brachial plexus exploration with first rib resection for thoracic outlet syndrome. Ultrasound demonstrated this pathologic first rib compressing the brachial plexus medially.

Conclusions: Ultrasound is a useful tool to define neurovascular anatomy for patients undergoing brachial plexus repair and may be helpful in preoperative surgical planning.

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FIBRINOGEN CONCENTRATION AND POSTOPERATIVE BLEEDING IN TOTAL HIP REPLACEMENT ARTHROPLASTY H.-S. Na, M.-H. Kim, Y.-T. Jeon, S.-H. Do Seoul National University Bundang Hospital, Anesthesiology and Pain Medicine, Seongnam, Republic of Korea Background

Total hip replacement arthroplasty (THRA) is associated with the intra- and postoperative substantial blood loss and increased transfusion requirement. We examine the relation of the hematologic variables and FIBTEM with postoperative blood loss (PBL).

Methods

In 23 patients undergoing THRA due to the avascular necrosis of femoral head, pre- and postoperative FIBTEM test and hematologic examination (hematocrit, platelet, fibrinogen, activated partial thromboplastin time, prothrombin time) were performed. PBL via closed suction drain was recorded, and we analyzed the correlation among those factors.

Results

PBL was greater in patients who had lower pre- and postoperative fibrinogen concentration (PBL = −0.92 × preop-fib + 653.6, r2 = 0.572, P < 0.001; PBL = −1.1 × postop-fib + 632.5, r2 = 0.616, P < 0.001). Low MCF of FIBTEM was also associated with greater PBL (PBL = −22 × preop-MCF + 722.0, r2 = 0.635, P < 0.001; PBL = −19.2 × postop-MCF + 553.9, r2 = 0.443, P = 0.001).

Conclusion

In this preliminary study, low fibrinogen level and low FIBTEM MCF parameter was related with greater blood loss in patients undergoing THRA.

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COMPARATIVE PERIOPERATIVE OUTCOMES ASSOCIATED WITH NEURAXIAL VERSUS GENERAL ANESTHESIA FOR ORTHOPEDIC SURGERY S.G. Memtsoudis, X. Sun, Y.-L. Chiu, S.S. Liu, O. Stundner, M. Mazumdar, S.E. Nigel 7Hospital for Special Surgery, Department of Anesthesiology, Weill Cornell Medical College, 1Department of Public Health, Weill Cornell Medical College, 2Department of Public Health, Weill Cornell Medical College, 3Hospital for Special Surgery, Department of Anesth, New York, NY, USA, 4Department of Anesthesiology and Intensive Care, Salzburg University Hospital, Salzburg, Austria, 5Department of Public Health, Weill Cornell Medical College, 6Hospital for Special Surgery, Department of Anesth Weill Cornell Medical College, New York, NY, USA I: The impact of anesthetic technique on perioperative outcomes remains controversial. Despite some suggestions that neuraxial anesthesia may offer benefits in perioperative outcome (1, 2), a paucity of data exists regarding this issue, particularly because large enough trials with sufficient power are unavailable and infeasible. Therefore, we studied a large national sample of primary joint arthroplasty recipients and hypothesized that neuraxial anesthesia would favorably impact on perioperative outcomes including mortality, complications, cost and length of stay.

M+M: Data collected from approximately 350 hospitals in a national database between 2006 and 2010 was accessed. Patients who underwent primary hip or knee arthroplasty (THA, TKA) were identified and included in our analysis. Utilizing billing codes, patients were divided into three anesthesia type categories: general (G), neuraxial (N), or combined general and neuraxial (GN) anesthesia. Patient and health care system related demographics and the incidence of postoperative complications were compared between groups. Differences in outcomes such as mortality, disposition status, length of hospital stay and hospital charges were analyzed.

R: We identified 382,236 records of patient undergoing primary THA and TKA. Of those, 10.5% were performed under N, 76.6% under G, 12.9% under G+N anesthesia, respectively. Patients undergoing their surgery under N or N+G were on average older than those operated on under G (66.9 years, 65.7 years vs 65.7 years, P< 0.0001). Overall comorbidity burden between groups was similar (average deyo index: 0.83, 0.82 and 0.86, respectively, P=NS). In-hospital and 30-day mortality were significantly lower among N and N+G groups compared to G (0.1%, 0.1% and 0.18%, P< 0.0001; 0.13%, 0.24%, and 0.22%, P< 0.0001). In-hospital complications were generally higher among the G versus the N and N+G groups, including pulmonary embolism (0.44% vs 0.35% vs 0.34%, P=0.0008), pulmonary compromise (0.81% vs 0.37% vs 0.61%, P< 0.0001), pneumonia (0.94% vs 0.69% vs 0.83%, P< 0.0001), cerebrovascular events (0.13% vs 0.07% vs 0.12%, P=0.0045), acute renal failure (1.75% vs 1.1% vs 1.43%, P< 0.0001), wound complications (1.54% vs 1.08% vs 1.28%, P< 0.0001), and any infection (4.5% vs 3.11% vs 3.87%, P< 0.0001). No difference in the rate for acute myocardial infarction was seen between groups (0.28% vs 0.24% vs 0.26%, P=NS). Other cardiac complications were only marginally decreased in the N versus G and N+G group (6.2% vs 6.42% vs 0.61%, P=0.0461). Transfusion requirements, average length of hospital stay and mean patient charges were lowest in the N versus G and N+G group (15.15% vs 18.53% vs 16.04%, P< 0.0001; 3.37 days vs 3.61 days vs 3.35 days, P< 0.0001; 42,849 USD vs 46,650USD vs 45,644 USD, P< 0.0001).

C: When considering a large national patient sample, the utilization of N versus G anesthesia for primary joint arthroplasty is associated with superior medical and economic outcomes, even though patients in the N group were older. However, the impact of a number of covariates will have to be tested in a multivariate regression, which is ongoing at this time.

Given the benefits of N over G, ways to promote neuraxial anesthesia among perioperative physicians should be sought 1) Rodgers A et al. BMJ. 2000 16;321:1493. 2) Sharrock, NE et al. Anesthesia and Analgesia. 1995; 80:242-248. A43

UTILIZATION OF TRANSVERSUS ABDOMINIS PLANE (TAP) CATHETERS IN LAPAROSCOPIC COLORECTAL RESECTIONS SIGNIFICANTLY DECREASES OPIOID CONSUMPTION AND SHORTENS LENGTH OF STAY V. Frenk, T. Bowling, P. Umamaheswaran, C. Littlejohn, S. McClane Stamford Hospital, Stamford, CT, USA Background:

Continuous TAP blocks are a recently described approach to providing analgesia to the anterior abdominal wall. Previous studies showed decreased opioid consumption and slightly shorter length of stay after single TAP injection in the patients undergoing laparoscopic colon resection (1,2). This retrospective review assessed the impact of continuous TAP catheter on postoperative opioid consumption and recovery after laparoscopic colorectal surgery.

Methods:

A total of 27 patients undergoing laparoscopic colorectal surgery at Stamford Hospital between October 2010 and October 2011 were compared (see Table1). The patients were treated postoperatively either with PCA alone or with TAP catheters in addition to the PCA.

Bilateral TAP catheters were placed after induction of general anesthesia in a supine position under the US-guidance as described previously (3). A bolus of 20 cc of 0.5% ropivacaine was injected via the needle on each side prior to catheter placement. Postoperatively, the catheters were attached to a portable infusion pump (ONQ C-bloc; I-Flow, Lake Forest, CA). A continuous infusion with 0.2% ropivacaine at 5-7 cc/hr/side was initiated in the PACU and continued for 3 days postoperatively. Primary outcomes were postop opioid requirements and length of stay. 1st day of flatus and 1st day of stool were also examined. 1 mg Dilaudid was noted to be equivalent to 7 mg morphine for comparison purposes. Continuous data was compared using the Student t-test.

Results:

TAP group used less opioids each day over the first three days. The patients within the TAP group tended to pass flatus earlier, and were found to pass stool and be discharged earlier than the PCA group, p< 0.05(see Table 2).

Conclusions:

This retrospective pilot study demonstrates that the addition of a TAP catheter block to a PCA postoperatively in laparoscopic colectomy patients leads to decreased opioid use, earlier passage of stool, and shorter length of stay. Given the compelling nature of the results in this study, a prospective, randomized controlled study is currently under IRB review to further evaluate the value of TAP catheters in improving overall post-operative patient outcomes in laparoscopic colon resections.

References:

1. Conaghan P, Maxwell-Armstrong C, et al. Efficacy of transversus abdominis plane blocks in laparoscopic colorectal resections. Surg Endosc. 2010 Oct;24(10):2480-4

2. Zafar N, Davies R, et. al. The evolution of analgesia in an ´accelerated´ recovery programme for resectional laparoscopic colorectal surgery with anastomosis. Colorectal Dis. 2010 Feb;12(2):119-24

3. Heil JW, Ilfeld BM, et.al. Ultrasound-guidedtransversus abdominis plane catheters and ambulatory perineural infusions foroutpatient inguinal hernia repair. Reg Anesth Pain Med. 2010 Nov;35(6):556-8

[Patient_data.pdf]

[results.pdf] A44

INTEREST OF THE PARAVERTEBRAL BLOCK FOR ANALGESIA AFTER BREAST CANCER SURGERY M. Ayedi, M. Smaoui, R. Barkia, H. Ben Soltana, K. Chaabane, M. Guermazi, K. Kolsi Hedi Chaker Hospital, Sfax, Tunisia Introduction: Major surgery for breast cancer is associated with high incidence of nausea, vomiting and postoperative pain. Thoracic paravertebral block (PVB) is carried out successfully for pain management after breast surgery.

The purpose of this study is to evaluate the efficacy and adverse effects of PVB in women undergoing breast surgery.

Materials and methods: This prospective, randomized, comparative, single-blind study was conducted after approval by the local ethics committee. Forty patients who underwent radical mastectomy were included in the study after informed consent according to the following criteria: Age> 20 and < 65 years, ASA class I or II. The non-inclusion criteria were: refusal of the patient, infection of the injection site, bleeding disorder, BMI> 35, hypersensitivity to local anesthetics, chronic analgesics or antiemetic treatment. Exclusion criteria were: anesthetic complications and technical difficulties. Patients were randomized into 2 groups: G1 (n = 20): 1.5mg/kg of bupivacaine 0.5% for metameric T4 into the paravertebral space and G2 (n = 20): did not have paravertebral block. Complementary analgesia by paracetamol and morphine was administered to both groups. We found the VAS at rest and in motion at 1, 2, 3, 9, 12 and 24 hours after surgery, the first analgesic request, the incidence of nausea and vomiting and adverse effects of paravertebral block.

Results: Demographic characteristics and duration of the intervention were comparable between the 2 groups. The average VAS at rest and movement were lower in group 1 up to 24 hours after surgery. The median (range) time of the first analgesic request was 94.5 minutes for group 1 versus 25.5 minutes for group 2, P< 0.05. The amount of morphine in SSPI was lower in group 1 (2.05 ± 0.22 mg vs 5.35 ± 2.11 mg, P < 0.001). The consumption of analgesics in 24 hours was significantly lower in the paravertebral block group. The incidence of nausea and vomiting was significantly higher in group 2 than in group 1. There were no complications associated with the implementation of the paravertebral block.

DISCUSSION : As part of a multimodal analgesia, paravertebral nerve blocks can provide excellent postoperative analgesic pain relief with less adverse effects and could also reduce the incidence of postoperative nausea and vomiting.

A45

VARIATIONS IN ECHOGENICITY OF PERIPHERAL NERVE BLOCK CATHETERS DEMONSTRATED IN A PORCINE ANIMAL MODEL R. Yun, E. Kim, E.R. Mariano, B. Carvalho Stanford University Medical Center, Stanford, Palo Alto Health Care System, VA Palo Alto Health Care System, Palo Alto, VA Palo Alto Health Care System, PAlo Alto, CA, USA Introduction: The successful placement of an ultrasound-guided continuous peripheral nerve block relies on image quality of the target nerve, surrounding structures, needle placement and perineural catheter (1,2). Catheter visualization during insertion is crucial to ensure accurate placement and analgesic efficacy of the perineural local anesthetic infusion. Although a number of studies have examined needle echogenicity, limited data exist regarding the echogenicity of perineural catheters. The objectives of this study were to determine the comparative echogenicity of various regional anesthesia catheters.

Methods: With Animal Use Committee approval, we employed a non-living porcine animal model to facilitate the comparison of different nerve block catheters echogenic qualities. Three commercially-available nerve block catheters [Arrow StimuCath (Teleflex Medical, Research Triangle Park, NC), B. Braun PeriFixFX and B. Braun Contiplex (B. Braun Medical Inc., Bethlehem, PA)] and a catheter under development to optimize echogenicity (Epimed International, Inc. Johnstown, NY) were studied. All catheters were inserted at 45 degrees to the skin by an un-blinded investigator who was not involved in subsequent tests. The order of catheter insertion was randomized and each catheter was tested 15 times for a total of 60 trials. The primary outcome was ordered visual echogenic ranking. Secondary outcomes included overall catheter visibility (0-10), artifact (0-10), shadowing (0-10), contrast (0-10), scanning time (secs), catheter length seen (%), and catheter photodensity in echogenic units. Catheter scanning and visual assessments were performed by investigators blinded to catheter brand and study order.

Results: There was a significant difference in median (IQR) echogenic rankings among the catheters studied (p=0.002). EpiMed was more echogenic than Arrow StimuCath (p< 0.001) and B. Braun PeriFixFX (p=0.019). B. Braun Contiplex® was more echogenic compared to the Arrow StimuCath (p=0.008). Figure 1 shows the percentage of times each catheter was ranked best. We observed no statistically-significant differences in ratings of artifact, shadowing, contrast or scan times among the catheters studied.

Conclusion: Results from this animal model demonstrate that catheters used for regional anesthesia display a wide range of echogenicity. Both Epimed and B. Braun Contiplex were more echogenic than Arrow StimuCath which was the least echogenic of the catheters studied. Future studies are required to show if this echogenic advantage observed in an animal model is also seen in a clinical model and if this leads to greater analgesic success with continuous peripheral nerve blocks.

References:

1. Reg Anesth Pain Med 2007;32:440-447

2. Reg Anesth Pain Med 2004;29:480-488

[1120411132655Figure1] A46

DOES THE ADDITION OF PHENYLEPHRINE TO IV EPHEDRINE FOR PROPHYLACTIC IV EPHEDRINE FURTHER REDUCES THE INCIDENCE OF HYPOTENSION FROM INTRATHECAL ROPIVACAINE FOR C/S? P. Patel, S. Cohen, S. Shah, M. Rao, M. Fenandez, R. Chhokra, S. Barsoum, J. Tse, C.W. Hunter UMDNJ-Robert Wood Johnson Medical School, New Brunswick, 5UMDNJ-Robert Wood Johnson Medical School, New Brunswick, UMDNJ-Robert Wood Johnson Medical School, New Jersey, NJ, USA Introduction: The use of prophylactic iv ephedrine or 6% Hetastarch is effective for prevention of hypotension from spinal anesthesia for cesarean section (C/S) when compared with lactated Ringer's solution (LR) alone. This study was designed to determine which treatment is the most effective for the prevention of hypotension from combined spinal- epidural (CSE) anesthesia for C/S: IV LR, IV 6% Hetastarch, IV ephedrine or IV 6% Hetastarch with IV ephedrine. Method: Following IRB approval & informed consent 244 parturients scheduled for elective C/S with CSE were studied. In all patients, the epidural space was located at L4-5 or L3-4 interspace using epidural needle in lateral decubitus position. The epidural catheter was inserted immediately following administration of 10 mg ropivacaine with 100 mcg epinephrine and 25 mcg fentanyl intrathecally. The patients were randomized into 4 groups: GI (n=60) received IV 2L LR prior to induction of spinal anesthesia, GII (n=66), received IV 1L LR & upon the spinal injection, received IV ephedrine 30 mg for 15 min, GIII (n=57) received IV 500 ml 6% Hetastarch + 1L LR prior to spinal injection, GIV (n=61) received IV 500 ml 6% Hetastarch + 1L LR prior to spinal injection, and upon the spinal injection also received IV ephedrine 30mg for 15 min. The cost of :1L LR is $0.86 ,1 Amp ephedrine is $ 0.32 , & 500 ml 6% Hetastarch is $16.16. Immediately after the spinal induction, the patients were positioned supine with left uterine displacement. BP was measured with automatic BP device every 2 min for the duration of the surgery. Hypotension was defined as a systolic BP (SBP) < 100 mm Hg & < 80% of the baseline BP. Hypotension was treated with IV boluses of ephedrine 5 mg q2 min. Reactive hypertension was defined as an increase in SBP > 20% above baseline. Conclusion: IV prophylactic ephedrine is cheaper and is as effective as 6% Hetastarch for the treatment of hypotension from intrathecal ropivacaine for C/S. A47

A NOVEL FRACTURE PAIN MODEL IN THE RAT M. Buys, T. Brennan San Antonio Military Medical Centers, San Antonio, TX, University of Iowa, Iowa City, IA, USA Background

Extremity injuries including long bone fractures make up the majority of injuries sustained by our military forces in Operation Enduring Freedom and Operation Iraqi Freedom. Current pain treatment modalities are limited and have side effects that can include sedation, dependence, respiratory depression, paradoxical hyperalgesia, and allodynia. Few animal models exist for the study of pain from traumatic long bone fractures. The rat and mouse models that have been previously described do not closely follow the mechanism or timeline for fracture repair seen in humans. We describe a novel rat femur fracture/repair pain model designed to closely mimic the method and timeline of fracture repair in humans.

Methods

30 male Sprague-Dawley rats were divided into three groups; Fracture/Repair (FR), Pin-Only (PO), and Control (C). In the Fracture/Repair group, a traumatic femoral fracture was produced in the left leg using a three-point impact device. Immediately following fracture, an anterograde intramedullary nail was placed to achieve reduction and fixation. Repair was confirmed by radiography. In the Pin-Only group, an anterograde intramedullary nail was placed without creating a femoral fracture. The Control group received only a sham incision over the pin placement site. All animals were survived after surgery and tested for pain behavior using an incapacitance meter and guarding scores for 28 days. After testing on day 28, the animals were sacrificed and both femurs harvested for micro CT and histologic analysis.

Results

One animal was excluded due to a comminuted/oblique fracture. Mean scores for incapacitance meter across all testing days were 49.8+/- 2.5% for Group C, 34.7 +/- 2.3% for Group FR, and 36.2+/-2.2% for Group PO. Groups FR and PO had significantly worse mean incapacitance scores than group C (p=0.001). Groups FR and PO had no difference in mean incapacitance scores (p=1). Guarding score means were 1.1+/-0.9 for Group C, 9.7+/-0.8 for Group FR, and 8.8+/-0.8 for Group PO. Groups FR and PO had significantly worse mean guarding scores than group C (p< 0.001). Groups FR and PO had no difference in mean guarding scores (p=1). When comparing individual test days, Group FX had significantly worse incapacitance meter scores than Group C on days 1,2,4,7, and 10 (p< 0.003) and worse guarding scores on days 1,2,4,7, and 10 (p< 0.03). Group PO had worse incapacitance scores than Group C on days 1,2,4 and 7 (p< 0.02) and worse guarding scores on days1,2,4,7,10,14, and 21 (p< 0.03). Group PO had worse guarding scores than Group FR on day 2 only (p=0.003). Incapacitance scores had no significant difference on any day between groups PO and FR.

Micro CT and Histology: pending

Conclusion

Our fracture model has a high degree of success for fracture fixation and shows robust pain behavior that peaks in the first week and returns close to baseline by day 21. Surprisingly, anterograde placement of an intramedullary nail by itself produces pain behaviors virtually identical to the fracture group in severity and duration. This model shows promise for use in studying novel analgesic approaches for traumatic long bone fracture pain.

[1112911091656Guarding_Graph.pdf]

[2112911091656Incapacitance_Graph.pdf]

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SURVEY OF CURRENT PRACTICES - PERIPHERAL NERVE BLOCK INSERTION BY ER PHYSICIANS FOR TREATMENT OF PAIN IN THE HIP FRACTURE PATIENTS L. Haslam, L. Jacques, L. Andrew, M. Van der Vyver, C. McCartney Sunnybrook Health Science Centre, Torotno, Sunnybrook Health Science Centre,, Toronto, Sunnybrook Health Science Centre, Toronto, ON, Canada In 2010-11 approximately 968 patients presented to emergency departments in the Greater Toronto Local Health Integration network (LHIN) with a hip fracture. The provision of timely and quality analgesia is often overlooked in the management of these patients. Nerve blocks, including the femoral nerve block and fascia iliaca compartment block, are more effective than traditional opioid analgesic regimens in reducing pain after hip fracture. In addition, the use of nerve block analgesia also reduces the incidence of delirium in these patients. Prevention of delirium has been shown to minimize length of stay in the acute care environment thereby minimizing physical and mental deconditioning. Although recommendations have been published, there is currently not a standardized approach to the analgesic management of pain in the hip fracture patient. Research suggests that femoral nerve blockade is best initiated early, when the patient presents to the emergency department. Emergency physicians are trained in ultrasound, and do insert this type of nerve block, however, incidence and techniques utilized are unknown. We are seeking to undertake the first survey of ER physicians and residents across the Greater Toronto LHIN looking at the current ER practice of nerve block analgesia in hip fracture patients. The primary aim is to determine the prevalence and range of techniques utilized. The secondary aims are to determine the extent of training in these techniques, to gauge opinion on the most important objectives for future training courses and seek an understanding of the barriers to establishing a more standardized approach to analgesia in hip fracture patients. This data will be used to develop a tailored multidisciplinary training program (ER physicians and anesthesia physicians) in block techniques and analgesic management of hip fracture patients, through collaboration with regional anesthetists at the Department of Anesthesia, Sunnybrook Hospital.

A49

EFFECT OF LOCAL ANESTHETIC VOLUME (15 VS 40 ML) ON THE DURATION OF ULTRASOUND-GUIDED SINGLE SHOT AXILLARY BRACHIAL PLEXUS BLOCK: A PROSPECTIVE RANDOMIZED OBSERVER-BLINDED TRIAL K. Schoenmakers, J.T. Wegene, R. Stienstra Sint Maartenskliniek, Nijmegen, The Netherlands Background and objectives:

Peripheral nerve block as an anesthetic technique plays an important role in modern regional anesthesia. The most important prerequisites for the use of peripheral regional anesthesia in daily clinical practice are success rate and safety. One of the advantages of ultrasound-guided peripheral nerve block is that visualization of local anesthetic spread allows for a reduction in dose. However, little is known about the effect of dose reduction on sensory and motor block duration. The purpose of this study was to compare the duration of sensory and motor axillary brachial plexus block with 15 and 40 mL mepivacaine 1.5%.

Patients and methods: Thirty patients scheduled for hand, wrist or forearm surgery were randomly allocated to receive ultrasound-guided single shot axillary brachial plexus block with either 15 (Group 15 mL, n = 15) or 40 mL (Group 40 mL, n = 15) mepivacaine 1.5%.

In the first 30 minutes after injection of the local anesthetic solution, a blinded observer assessed the onset of sensory and motor block every 5 minutes. Sensory block of the medial antebrachial cutaneous, musculocutaneous, radial, median and ulnar nerves was assessed by pinprick. At the same intervals, motor block of the musculocutaneous, radial, median and ulnar nerve was assessed. After surgery, upon arrival at the recovery, offset of sensory and motor block was assessed by a blinded observer every 15 minutes in the same manner as preoperatively until full recovery.

Primary outcome was overall sensory block duration. Secondary outcome parameters included overall motor block duration, block duration of individual nerves, block onset and time to first request of postoperative analgesia (TTFR).

Results: Two patients in group 15 mL needed an additional rescue block before surgery and were excluded from subsequent analysis. The median overall and individual duration of sensory and motor block was significantly shorter in group 15 mL as compared to Group 40 mL (see Table 1 and Figures 1 and 2).

Overall duration was largely determined by the duration of sensory and motor block of the ulnar nerve: In 10/13 patients in group 15 mL and 10/15 patients in group 40 mL, the ulnar nerve was among the last to recover. Time to first request of postoperative analgesia was significantly reduced in group 15 mL (163 ± 39 min versus 235 ± 59 min respectively, p < 0.05). There were no differences in the other block characteristics.

Conclusions: In axillary brachial plexus block with mepivacaine 1.5%, reducing the dose from 40 mL to 15 mL (62.5%) shortens the overall duration of sensory and motor block by approximately 17-19%, reduces sensory and motor block duration of individual nerves with 18-40% and decreases the time to first request of postoperative analgesia by approximately 30%.

[1110811094720Table_1.jpg]

[2110811094720Figure_1.jpg]

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DEVELOPMENT AND IMPLEMENTATION OF AN AUTOMATED, INTEGRATED, CONTINUOUS ACUTE PAIN PATIENT INFORMATION MANAGEMENT SYSTEM (ACUTE PAIN PIMS) S.D. Adhikary, S. Riemondy, P.M. McQuillan Penn State College of Medicine, Milton S.Hershey Medical Center, Hershey, PA, USA Introduction: Traditionally, acute pain management consults, procedures, and follow-up have been documented in the medical record as a single point of entry, either by electronic or hand written methods.1, 2 Pain scores and analgesic requirements during an in-patient admission are subsequently documented independently in different locations in the patients medical record. Shortcomings with these methods include:

1. Data is discontinuous and entered by different teams (APMS, nursing, surgical) at different times.

2. Gaps in evaluation and management of pain

3. Variability in assessment

4. Incomplete documentation

5. Inconsistent communication between nursing, APMS, and Surgical teams.

We have developed an Acute Pain PIMS that is integrated with the Electronic Medical record (EMR) in our institution. Once an acute pain procedure form has been generated for a patient and uploaded to the EMR, PIMS automatically imports patient information, in a continuous fashion, to the acute pain database. Patient information includes: name, surgical procedure and service, APMS treatment and pain scores, as well as the time and dose of pain medication administered. The system is searchable and was designed to be robust, so that in the future, other parameters can be added.

Methods: A team consisting of specialists in Information Technology (IT), billing, acute pain nurses and physicians designed the PIMS in approximately 8 months. Joint Commission (JC) and Centers for Medicare & Medicaid Services (CMS) guidelines and compliance requirements were also built into PIMS. PIMS use has 4 components: A) Acute Pain procedure and medication documentation, B) Creation and uploading the document to PIMS, C) Data entry, and D) Report generation.

Component A: Acute Pain procedure and medication documentation is completed by the APMS team (resident/attending) performing the acute pain procedure.

Component B: Creation and uploading the document to PIMS is completed by the APMS attending after verifying and electronically signing the APMS procedure document.

Component C: Data entry is completed by the point of care team on the inpatient wards. This is usually the nurse responsible for the patients care.

Component D: A report can be generated by anyone with access to the EMR. One is also automatically generated every 12hr, including all patients having had acute pain procedures in the previous 48 hrs.

Discussion:

The implementation of an Acute Pain PIMS has led to improvement in our APMS in a number of ways including:

1. We are now able to evaluate the efficacy of all Acute Pain procedures in one report before interacting with the patient. This information is also readily available to all care teams.

2. Analgesic requirements and pain scores are now monitored continuously for 48hrs after acute pain procedure.

3. The Acute Pain PIMS links the acute pain procedure details with the patients pain management. This information has led to better evaluation of the effectiveness of procedure and detection and elimination of gaps in pain management.

4. This system fosters communication between care teams.

5. The implementation of Acute Pain PIMS, with the inclusion of required fields for documentation, ensures accuracy and compliance with regulatory requirements.

6. Utilization of a consistent, validated evaluation tool for peri-operative pain management.

Conclusion:

To our knowledge, this is the first report of an integrated, continuous, electronic APMS data system. We believe implementation of an Acute Pain PIMS leads to a better and more comprehensive peri-operative pain management program.

Reference:

1. Gerancher JC, Viscusi ER, Liguori GA, et al. Development of a standardized peripheral nerve block procedure note form. Reg Anesth Pain Med 2005;30:67-71.

2. Neal JM, Wedel DJ. Ultrasound guidance and peripheral nerve injury: is our vision as sharp as we think it is? Reg Anesth Pain Med 2010; 35:335-7.

A51

USE OF ULTRASOUND GUIDED POPLITEAL FOSSA INFILTRATION TO CONTROL PAIN AFTER TOTAL KNEE ARTHROPLASY: A PROSPECTIVE RANDOMIZED OBSERVER-BLINDED STUDY S. Sinha, J. Abras, A. Sivasenthil, D. Freitas, J. D'Alessio, J. Barnett, R. Weller, C. Lewis St.Francis Hospital and Medical Center, Hartford, Hartford, CT, Forest School of Medicine, North Carolina, North Carolina, NC, Connecticut Joint Replacement Institute, Hartford, CT, USA Introduction: We have previously demonstrated that selective tibial nerve(TN) block in the popliteal fossa provides equivalent analgesia compared to sciatic nerve when combined with femoral nerve(FN) block for total knee arthroplasty(TKA)(1). Ultrasound guided(USG) infiltration of the interspace between the popliteal artery and the capsule of the knee (iPACK) with local anesthetic solution maybe an alternative option in controlling posterior knee pain. We postulated that with iPACK, the main trunk of the TN will be spared and only the terminal branches innervating the posterior knee joint will be blocked. In this study we describe the novel use of USG iPACK to control postoperative posterior knee pain and compare the efficacy of this technique to conventional TN block.

Methods: In this IRB approved study, 14 patients have so far given written informed consent. All patients were premedicated as per our multimodal analgesia regimen (Table 1). A FN catheter was inserted after which patients were positioned prone and either a USG iPACK (Posterior Capsular group) or TN block (Tibial group) was performed based on randomization.

For USG iPACK , the popliteal fossa was scanned just proximal to the popliteal crease to visualize the femoral condyles. The probe was then moved proximally until the condyles disappeared and the shaft of the femur was visible. At this level the needle was inserted in a medial to lateral direction between the popliteal artery and the femur until the needle tip was 2-3 cm beyond the lateral edge of the of the popliteal artery (Fig 2). Thirty milliliters of ropivacaine 0.2% with Epi 1:300K was injected as the needle was gradually withdrawn to infiltrate the tissue interspace

For USG TN block the block needle was inserted just proximal to popliteal crease using in- plane, mediolateral needle trajectory to surround the nerve with a maximum of 15ml of ropivacaine 0.5%.

For surgery general anesthesia was supplemented with fentanyl or hydromorphone if needed. In the post-anesthesia care unit (PACU), sensorimotor function was tested by blinded PACU nurses including dorsiflexion, plantarflexion, and sensation to cold on the planter aspect and dorsum of foot using a three point scale (0=normal, 1=decreased and 2=absent). Standard analgesia protocol was continued post surgery (Table 1). Pain scores and narcotic consumption in PACU and 48 hours after PACU discharge were tracked.

The technique of USG iPACK was simulated in 2 fresh cadavers with dye and the popliteal fossa dissected to determine the spread of injectate.

Results: Demographic variables were similar between groups (Table 2). There were no differences in the pain scores and opioid consumption between groups (Table 3; Fig 1). No patient in either group developed a foot drop.

Dissection of the popliteal fossa in the cadaver showed that the dye spread adequately in the tissue plane between the popliteal artery and the posterior knee capsule sparing the tibial and peroneal nerve (Fig 2)

Discussion; Preliminary data suggests that USG iPACK provides equivalent analgesia compared to TN block when combined with FN block. This technique maybe an alternative method in controlling posterior knee pain following TKA.

References: 1.Sinha S. Reg Anesth Pain Med 2010; 44

[1121811214621Table_1Post_Cap.doc]

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COST-EFFECTIVE MODEL FOR ULTRASOUND-GUIDED PARAVERTEBRAL BLOCK J.D. Jochman, R.A. Jacobs, M.J. Donnelly, K.M. Schroeder University of Wisconsin Hospital and Clinics, Madison, Madison, WI, USA Introduction: The paravertebral block is an effective technique to provide surgical anesthesia for certain procedures of the chest wall and abdomen as well as post-operative and post- traumatic analgesia. However, performing this block is associated with certain risks, especially among less experienced providers. One particular concern is needle entrance into the pleura causing pneumothorax. To help mitigate this risk, manufactured models are used for training purposes. However, these models are costly and thus may not be widely available for use. In an attempt to provide more models for practicing the block, a cost-effective version was created using simple, household items.

Methods: To create the model, 20 grams of unflavored gelatin and 10 grams of psyllium fiber were added to 250 mL of boiling water. This substance required slow and constant mixing to ensure homogenous consistency. After complete mixing, the substance was carefully poured into a 32-ounce clear plastic food storage container to a height of 1 cm. This was then cooled for about 30 minutes to allow the gelatin to set. Next, sweetened fruit wraps opposed by a thin layer of olive oil were situated atop the mixture to mark the superior costotransverse ligament (posterior border) and parietal pleura (anterolateral border). The olive oil was intended to create the plane to be targeted for anesthetic infiltration under ultrasound guidance. Two, 1-inch aluminum square hardware bars were then placed upon the fruit wraps to simulate two vertebral transverse processes. Lastly, the remainder of the gelatin/fiber mixture was slowly poured over the structures to a total height of 7.5 cm. The mixture was kept refrigerated for about 24 hours to allow complete solidification of the gelatin. After the cooling period, the model was tested using two types of needles (Perifix 17G x 3-1/2 inch Tuohy needle; Pajunk Uniplex Nanoline 21G x 100 mm needle) under ultrasound guidance (SonoSite M-Turbo, Bothel, WA).

Results: Overall the model was felt to authentically represent the intended anatomic structures and provided the proper consistency of subcutaneous tissues. Using both in-plane and out-of-place ultrasound approaches, it was possible to visualize the peripheral nerve needle passing appropriately through the simulated superior costotransverse ligament. Saline was able to be injected to spread open the targeted space.

Conclusion: This cost-effective model for paravertebral blocks accurately simulated the necessary structures that would be encountered when performing the block on actual patients. Because the materials used were common and inexpensive and the model itself was not complicated to create, this would be an attractive option for training programs involved in teaching regional anesthesia techniques.

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SUCCESSFUL TREATMENT OF SEVERE PHANTOM LIMB PAIN WITH KETAMINE AND MEMANTINE J.A. Villanueva, J.T. O'Neil, K. Colfer, E.R. Viscusi Jefferson Medical College, Thomas Jefferson Univer, Thomas Jefferson University Hospital, Philadelphia, Philadelphia, PA, USA Introduction:

We present the first reported use of oral memantine as an adjunctive medication for severe new onset phantom limb pain following successful management with intravenous ketamine.

Case report:

A 57 year old male had a sudden onset of acute left lower phantom limb pain 2 days after he underwent a left hindquarter hemipelvectomy with resection of a pelvic angiosarcoma diagnosed in the setting of a prior left hip replacement. His pain was described as a constant burning sensation accompanied with uncomfortable paresthesia in his left lower phantom limb. Severity of his phantom limb pain persisted at 8/10 on the Visual Analogue Scale (VAS) despite epidural analgesia with ropivacaine 0.2%, opioid patient controlled analgesia (PCA), and oral pregabalin. Intravenous ketamine was then started at an infusion rate of 10mg/hr and titrated to 25mg/hr over several days. His phantom limb pain decreased to 4/10 pain with the ketamine infusion, oral pregabalin, and opioid PCA. Memantine was then started at 10mg twice daily in order to control his phantom limb pain as we transitioned him to oral medications in preparation for discharge. After discontinuation of his ketamine infusion and opioid PCA, the patient reported no increased severity of his phantom limb pain. He maintained 4/10 pain on the VAS and increased his functional level while on low-dose oral opioids, pregabalin, and memantine 20mg twice daily. He reported no side effects of headaches, confusion, dizziness, agitation, or hallucinations while on memantine. Discussion:

Memantine is a N-methyl-D-aspartate (NMDA) antagonist widely used for the treatment of dementia of the Alzheimers type (DAT). After an extensive literature search we found several case studies reporting the use of memantine in chronic phantom limb pain. Nevertheless, we believe this to be the first publication of the use of oral memantine that resulted in adequate analgesia for acute post-surgical phantom limb pain during the transition from ketamine infusion and opioid PCA to oral pain medications.

Conclusion:

Oral memantine, an NMDA receptor antagonist, may be useful as an extension of successful treatment with intravenous ketamine for controlling acute post-surgical phantom limb pain in conjunction with opioids and standard neuropathic pain treatment. Given the success of this case, further studies may be warranted.

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AN EDUCATIONAL TOOL FOR SIMULATION OF ADVANCED ASPECTS OF ULTRASOUND GUIDED REGIONAL ANESTHESIA - LOCAL ANESTHETIC SPREAD AND CONTINUOUS CATHETER PLACEMENT L. Maracaja-Neto, J. Echavarri, J. Rushbrook, R. Twersky, D. Dimaculangan SUNY Downstate Medical Center, New York, New York, NY, USA Background- Proficiency in ultrasound guided regional anesthesia (UGRA) demands knowledge and training. Simulation sessions using tissue substitutes such as ultrasonic phantoms (UPs) are strongly recommended before working with patients in order to reduce complications such as failed blocks, injury to the surrounding anatomic structures and nerve damage(1). The similarity between the ultrasonic images created by UP and the ability to perform all the steps of the procedure during the simulation make the training process much more valuable. In addition to tracking the needle as it is advanced from skin to the nerve UGRA can depict the local anesthetic (LA) spread around the nerve "hypoechogenic halo" . The observation of the halo provide an evidence that the LA is not being injected intravascular or intraneural, further minimizing these complications. The visualization of the catheter can potentially prevent kinks. These features cannot be simulated in existing UPs - manufactured or otherwise. (3) Here we describe construction of an UP that can simulate LA injection and tracking catheter insertion. Methods- UP was created with the following specifications (Figure 1):1. A target simulating nerve bundles: adjacent sections of cut stalks of peeled and cooked (100C degrees /5min ) asparagus. The microstructure of the asparagus stalk gives ultrasonic images similar to nerve bundles in the short axis views (2). Potential space that can simulate LA spread: a collapsed and sealed flexible polyvinyl recipient (sealable plastic pouch). Sufficient background material in the liquid state is placed in the polyvinyl recipient to coat the target and all air is excluded and the recipient sealed(3). Ultrasonic background material inside and outside of the polyvinyl recipient: agar/pysillium in the approximate ratio 10:2. Solidified agar gives a firm sensation during needle insertion while the addition of psyllium, a soluble fiber, increases background echogenicity, simulating subcutaneous tissue. Result-Ultrasound Images: The Sonographic images obtained during a simulated performance of nerve block are shown in Figure 2.

Discussion- The visualization of a hypoechogenic halo is an important predictor of a successful block. The creation of this halo portends the rapid onset of anesthesia(4). To obtain a halo, it is necessary to advance the needle tip very close to the nerve and inject in one or several points to spread the LA around the circumference of the nerve. When the needle crosses the plastic layer it reproduces the tactile sensation of passage through a fascia. The expandable polyvinyl recipient inside the elastic agar medium is the cornerstone to demonstrate fluid spread. This UP can be built in about one hour and the shelf-life lasts 3 weeks, if kept at low temperatures. Conclusion-We describe an UP which can improve training in performance of UGRA. The visualization of LA spreading and catheter placement are important aspects that can be simulated in this model.

References: 1. Anaesthesia 2010 Apr; 65 Suppl 1:1-12. 2. Ultrasound Med Biol. 2010 Jun; 36(6):861-73. 3. Reg Anesth Pain Med. 2011 Mar-Apr;36(2):162-70. 4. Reg Anesth Pain Med. 2010 Nov;35(6):559-64.

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ASSESSMENT OF PERIPHERAL NERVE BLOCK WITH INFRARED THEMOGRAPHY AND SKIN CONDUCTANCE BEFORE AND DURING DEEP SEDATION - A PILOT STUDY J.Y. Kazansky, V. Kuklin, J. Mercer, L. Bjertnaes University Hospital Northen Norway, University of Tromso, Tromso, Tromso, Tromsø, Norway Background and aims: The "Gold standard " for clinical evaluation of peripheral nerve block (PNB) with pinprick/cold sensation (PCS) and muscle tonus cannot be used in patients during deep sedation or in persons with communicative difficulties. To our knowledge, changes in skin temperature determined by infrared thermography (IRT) have not been used for peripheral nerve block (PNB) assessment during deep sedation. In awake patients pain can be monitored by skin conductance fluctuations (SCF), which are strongly correlated with the Numeric Rating Scale. A literature search revealed no previous studies employing SCF for assessment of PNB, neither in the awake nor in the anaesthetized condition. This pilot study has been made to investigate whether changes in mean dorsal hand skin temperature (Tmsk) measured by IRT and SCF can be used for PNB assessment in awake condition. In addition we have investigated whether IRT can be used to assess PNB during deep sedation

METHODS. Twelve ASA I-II adults requesting deep sedation, scheduled for elective wrist/hand surgery. All blocks were performed by the same anesthesiologist using an ultrasound guided sagital infraclavicular approach. Four time points (TP's) were used: TP1 (10-min before PNB), TP2 (30-min after PNB), TP3 (before sedation), TP4 (during deep sedation prior to surgery). Clinical evaluation (scale: presence (1) & or absence (0) of sensation & muscle control). Tmsk measurements were carried out in blocked and unblocked arms at all TP's. SCF measurements (calculated as peaks per second during 15 second intervals) were made at TP1 (before the block) and compared with data after the block at TP2.

RESULTS. One patient with failed block had a scale of 1 with PCS in all areas innervated by median, ulnar and radial nerves. This correlated with no difference in PNB assessment between blocked and non blocked arms using IRT and SCF. Eleven patients had PNB clinical evaluation scale 0 in all innervations areas of the three hand nerves. In these patients there were no differences in Tmsk between blocked and unblocked hands (33.2°C & 33.0 °C respectively) at TP1. The difference in Tmsk between blocked and unblocked hands compared to TP1 was evident at TP2, TP3 (+1.2°C & -3.1°C respectively) and at TP4 (+1.3°C & -1.8°C respectively). In ten patients with successful PNB SCF always responded to pinprick in unblocked arms at TP1 & TP2 (from 0,07±0,01 to 0,26±0,09 & from 0,09±0,01 to 0,29±0,07 respectively). In the same patients at TP2 SCF responses in all dermatomes were insignificant (from 0,01±0,01 to 0,03±0,03 respectively) in blocked arms .

Conclusion: PNB can be assessed from measurements of Tmsk by IRT during deep sedation. However, IRT cannot be used to differenciate PNB in skin areas innervated by the radial and median nerves. SCF can be used for PNB evaluation in awake patients. Although these initial results are promising, further studies combining IRT with SCF for assessment of PNB are needed to refine these techniques.

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RESPIRATORY ARREST IN PATIENTS UNDERGOING ARTERIOVENOUS GRAFT PLACEMENT WITH INTERSCALENE AND SUPRACLAVICULAR BLOCK: A CASE SERIES A. Afonso, Y. Beilin Mount Sinai Hospital, New York, NY, USA Regional anesthesia for upper extremity surgery, including creation of arteriovenous (AV) grafts and fistulas, is increasingly more common. Decreased length of hospital stay, increased patient satisfaction, effective postoperative analgesia, avoidance of airway instrumentation and improved graft patency are just some of the reasons regional anesthesia has gained popularity.

Hemidiaphragmatic paresis is a common complication of brachial plexus blocks, occurring 67% of the time following a supraclavicular block and up to 100% of the time following interscalene block, though it rarely manifests with clinical symptoms in healthy patients. We describe 3 cases in a single institution over a 6-month duration of respiratory failure after ultrasound-guided brachial plexus blocks for AV graft placement. This is the first case series describing this complication in patients with renal failure.

Case 1: A 48-year-old male with hypertension, congestive heart failure requiring an implantable cardioverter defibrillator and morbid obesity with a body mass index (BMI) of 40.3 presented for AV graft insertion for dialysis for end-stage renal disease (ESRD). After placement of a supraclavicular block with mepivacaine 1.5%, 40 mL, the patient became severely short of breath and the procedure was canceled. Thirty minutes later the patient developed a pulseless electrical activity (PEA) arrest. Intubation and advanced cardiac life support (ACLS) was initiated with successful resuscitation.

Case 2: A 61-year-old after a failed renal transplant presented for AV graft insertion. PMH included pulmonary hypertension, asthma, obstructive sleep apnea, hypertension, BMI of 44.6, diabetes (DM), and cerebrovascular accident. A supraclavicular block with mepivacaine 1.5%, 40 mL was placed with ultrasound guidance. With and additional 15ml of 1% lidocaine injected after rescanning the brachial plexus. Fifteen minutes later, the patient was unresponsive. ACLS with tracheal intubation was initiated with immediate return of circulation.

Case 3: A 67-year-old with hypertension, asthma, BMI 38.4 and DM presented for AV graft formation dialysis. After supraclavicular block placement with mepivacaine 1.5%, 20 mL and bupivacaine 0.5% 20 mL, the patient became uncooperative and with shortness of breath. The patient was intubated and transferred to the intensive care unit.

A number of respiratory complications occur in patients with chronic renal disease ranging from pulmonary edema and effusions to sleep apnea. Sleep apnea is also 10-fold higher in patients with end-stage renal disease than the general population, with over 60% patients on dialysis with this diagnosis. Patients with a BMI > 35 kg/m2, as seen in our patients, also have decreased functional residual capacity, which can also increase the likelihood of symptomatic respiratory issues following these blocks.

It is unclear if there is a subset of patients with ESRD who are at greater risk for respiratory embarrassment following supraclavicular or interscalene blocks. We recommend careful patient selection that includes evaluation of patient BMI, concurrent cardiovascular and respiratory disease when choosing the anesthetic technique for this class of patients. A57

REVIEW OF SINGLE-CENTER EXPERIENCE WITH 466 PREOPERATIVE TRANSVERSE, IN-PLANE, ULTRASOUND-GUIDED THORACIC PARAVERTEBRAL BLOCKS FOR POSTOPERATIVE PAIN CONTROL FOR MASTECTOMY WITH IMMEDIATE RECONSTRUCTION J. Anderson-Dam, P. Stefanovich, L. Warren, K. Fleischmann, N. Sunder Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA Background: Preoperative thoracic paravertebral (TPVB) block can be used for postoperative pain management following breast surgery. A barrier to this is the risk for complication associated with the multi-level, landmark based approach - including an incidence of pleural puncture and pneumothorax of 1.1% and 0.5%. In this study, we present the experience of a single institution using single-level, transverse, in-plane ultrasound (US)-guided TPVB for post-operative pain control for mastectomy with immediate reconstruction. Methods: All patients who underwent US-guided TPVB from 1/1/2010 to 7/31/2011 were reviewed from the prospectively gathered regional database at the Massachusetts General Hospital. This database records the block performed, the amount of local anesthesia utilized, the subjective length of block (defined by the patient as the time of increased pain level), complications, and patient satisfaction with the block. Results: A total of 284 patients underwent TPVB during the time period reviewed, of which, 277 (97.5%) had follow up. 182 were bilateral blocks, 43 were left-sided, and 59 were right sided representing a total of 466 blocks. Of those who had follow-up, the rate of satisfaction was 85.6% (bilateral - 84.4%, left - 90.2%, right 85.9%). There were three notable complications in this series - one patient with bilateral finger numbness post-operatively, one patient with epidural spread noted by lower extremity weakness and urinary retention, and one patient who had an exaggerated vagal response after block placement with asystole requiring brief chest compressions without subsequent sequelae. There were no episodes of pneumothorax. Conclusions: In our limited series, single level, transverse, in-plane US-guided TPVB for postoperative pain control following mastectomy with reconstruction is safe and effective.

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THE COMPARISON EFFECT OF BUPIVACAINE 25% AND LIDOCAINE 2% INJECTION IN INCISICIONAL SITE FOR CONTROL OF PCNL SURGERY PAIN H. khoshrang Guilan University of Medical Sciences, Rasht, Iran Introduction: pain is unlikely sense that cause temporary or tissue injury and one of health problem in the world is how to control it? PCNL is a less invasive technique for kidney stones resection and it is a elective method for stag horn kidney stones but it is not without secqule.one of the most important sequel is post operative pain that it cause suppression of respiratory function. We try to compare efficacy of bupivacaine 0.25% , Lidocaine 2% and normal saline for controlling of pain after PCNL surgery.

Materials and methods: : in double blinded clinical trial we selected 60 patients in three groups .(the mean of age 35+/_20)in the end of surgery and after discharge of nephrostomy tube , we injected Bupivacaine 25% in dose of 0.5 mg/kg(groupI)Lidocaine 2% in dose of 4 mg/kg (group II) and normal saline (group III)that added with distilled water up to 20 cc for all groups, in the location of surgery incision. We measured VAS in hours of 0,3,6,9,12,15,18 for considering of pain control and Pethedine was injected 0.5 mg/kg /IV when VAS was above 3 .we used SPSS V14 for data collection and t- test and One way ANOVA for analysis. Value less than 0.05 was significant.

Results: There was no differences between 3 groups as age and sex. the mean of VAS in first 12 hour after surgery in group I was 4.05 ,4.65 in group II and 5.22in groupIII.There was significant relationship of VAS between GI and GIII(p=0.001)but no difference statically in VAS between GII and GIII and GI and GII. The mean doses of the injected pethedine in groupI,II and III were 58,68.5 and 88.5mg.there was significant differences between group I and III(P= 0.001) and group II and III(P=0.004) but there was no difference between group I and II.

Discussion: injection of Bupivacaine and Lidocaine in the location of nephrostomy tube is more effective than placebo for control of PCNL surgery pain and need to numbers and doses of Pethedine.

Keywords: pain control, PCNL, Bupivacaine, Lidocaine A59

TRAINING PEDIATRIC REGIONAL ANESTHESIOLOGISTS, A NEW APPROACH K. Boretsky, D.M. Hall-Burton, J. Chelly , University of Pittsburgh Medical Center, University of Pittsburgh Medical Center, Pittsburgh, PA, USA Background: The complexity of perioperative pediatric pain intervention, especially the applications of regional anesthesia, has increased in the past thirty years. The Pediatric Anesthesia Leadership Council and the Pediatric Anesthesia Program Directors are discussing options for addressing the increased demand for expertise in this area in the form of optional second year fellowships in Pediatric Regional Anesthesia and Acute Perioperative Pain Management. The University of Pittsburgh Medical Center (UPMC) has a robust and accomplished fellowship program in Regional Anesthesia and in July 2011 created a program open to pediatric anesthesia fellowship graduates titled Regional Anesthesia Fellowship: Pediatric Track (RAF:PT). The goal was to create a program whose graduates function at an expert consultant level in all aspects of Pediatric Regional Anesthesia and Acute Perioperative Pain Management.

Methods: Admission to the RAF:PT is open to graduates of an ACGME accredited pediatric anesthesia fellowship. The pediatric track fellows (PTF) are enrolled in the UPMC Regional Anesthesia Fellowship (parent program) and must fulfill all requirements of its 12-month program. Credit can be given for up to 4 months of previous fellowship level training including: 1 month of research, up to 2 months of general anesthesia, up to 2 months of regional anesthesia and pain management. Specific requirements of the RAF-PT include 1 month in research and 5 months on the Acute Perioperative Pain Service at the Childrens Hospital of Pittsburgh of UPMC. The balance of the requirements is fulfilled in adult regional anesthesia rotations and other electives as allowed by the parent program. Adult regional anesthesia rotations include rotations at a university hospital with specialization in transplantation and trauma, a university hospital specializing in surgical oncology and orthopedic joint replacement, an ambulatory facility specializing in sports medicine and orthopedic surgery, and other affiliated facilities as deemed appropriate to provide a rich and varied clinical exposure. The RAF:PT has written goals and objectives emphasizing competencies specific to pediatric care. PTFs participate in all educational activities of the parent program including structured lectures and conferences.

Discussion: Pediatric anesthesia leadership recognizes the need for subspecialty instruction in pediatric regional anesthesia and perioperative pain management. It is unclear how this training may be best accomplished. A consensus committee of program directors produced the Guidelines for Regional Anesthesia Fellowship Training, at a time when no pediatric programs existed. At UPMC we incorporated the pediatric track within the framework of our regional anesthesia fellowship, which follows the published guidelines. This allows the PTFs access to the resources and infrastructure associated with the parent program including weekly lectures, monthly journal clubs, administrative support, and exposure to a larger variety of patients and surgical procedures. Our first fellow will graduate in April 2012.

Conclusion: This program may serve as a model for future fellowship training in pediatric regional anesthesia and perioperative pain management.

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EFFECT OF EPIDURAL VS GENERAL ANESTHESIA FOR TOTAL MASTECTOMY ON OESTROGEN RECEPTOR-NEGATIVE BREAST CELL LINE PROLIFERATION IN VITRO J.S. Green, H. Ostergaard, B.C. Tsui Dept. of Medical Microbiology & Immunology, University of Alberta, Department of Anesthesia and Pain Medicine, University of Alberta Hospital, Edmonton, AB, Canada Background. A difference in oestrogen receptor-negative breast cell line proliferation in vitro has been reported when cells were cultured in pre and post-operative serum from general anesthesia and regional (paravertebral) anesthesia groups of patients undergoing total mastectomy1. The difference was seen when cells were cultured in patient serum concentration of 10% but not in patient serum of 5% or 2%. We proposed that the use of an epidural catheter at a high thoracic spinal level would provide more complete regional anesthesia and analgesia limiting the use of opiates and general anesthetic agents which may lead to an increased difference in cell proliferation compared to the previous study.

Method. Following approval from the institutional ethical board patients with breast cancer scheduled for total mastectomy were recruited. After obtained informed consent a stimulating ´Tsui´ epidural was placed with the tip between T1 and T4 and epidural block was established prior to surgery. Sedation or light general anesthesia was provided using propofol. The epidural block was continued overnight for post-operative analgesia. Blood samples were taken preoperatively(a), immediately postoperatively(b), and the following morning(c). Serum was collected following centrifugation and stored at -70 Celsius. Serum samples were then collected from patients undergoing general anesthesia for comparison. The serum was combined with the oestrogen receptor-negative MDA-MB-231 cell line in concentrations of 2, 5 and 10% following the method in the previous study2. Batch testing was repeated to limit experimental error.

Results. Serum was tested from 9 patients in the epidural group and 10 patients in the general anesthesia group. All results from the batch testing are plotted on the graph. The graph shows the data from the 10% patient serum group. Results are expressed as percentage change in proliferation from pre-induction to the immediate post operative period (Day 0) and from pre- induction to next day (Day 1). No statistical difference in cell proliferation was found between the 2 groups for serum concentrations of 2, 5, or 10%. In the epidural group opiates were avoided in 7 patients, 1 patient received 100mcg fentanyl and 1 patient received 50mcg fentanyl. Total dose of propofol ranged from 220 to 1080mg in this group. The general anesthesia group all received volatile agents and morphine.

Discussion. A difference in oestrogen receptor-negative breast cell line proliferation between the epidural and general anesthesia groups was not seen in our study. We hypothesized that the difference in cell proliferation in the previous study was due in some way to the regional vs general anesthesia effect on factors in patient serum. If this were true we would have expected to see a similar or more marked difference between regional and general anesthesia groups in our study. The reported difference in the original study may have been due to other reasons. We plan to repeat our study using patients from a paravertebral group to see if we can reproduce the results seen in the original study.

Reference.

1.Deegan, C.A., et al., Effect of anaesthetic technique on oestrogen receptor-negative breast cancer cell function in vitro. Br J Anaesth, 2009. 103(5): p. 685-90

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THE EFFECT OF ACUTE PAIN AND EMOTIONAL STRESSORS ON SKIN CONDUCTANCE INDICES J.J. Bae, S. Gungor, V. Buschiazzo, C. Ford, K. Gritsenko, H. Storm, P.J. Christos Hospital for Special Surgery, Anesthesiology, New York, Montefiore Medical Center, Bronx, NY, USA, University of Oslo, Oslo, Norway, Public Health Weill Cornell Medical College, New York, NY, USA Background: Skin sympathetic activity influences skin conductance indices, and this can be measured by a non-invasive monitor. Recent studies have shown that the number of fluctuations of skin conductance per second (NFSC) is a useful parameter for objectively assessing acute postoperative pain. In our pilot study, we demonstrated weak correlations between acute pain and skin conductance indices (SCI) - peaks per second (PPS) and area under the curve (AUC) - using the cut off value of 0.33. In addition to pain, there is evidence that SCI may be influenced by other factors such as anxiety, intellectual task and nausea. The influence of these factors on SCI in postoperative setting is largely unknown. We conducted this study to investigate the correlations between the SCI and other emotional stressors such as anxiety, intellectual task and nausea in postoperative patients. Methods: After IRB approval, 50 adult patients undergoing total hip and total knee replacement procedures were enrolled. On postoperative day (POD)1 and POD2, patients were evaluated for their emotional stressors such as anxiety, intellectual task performance and nausea. Peaks per second and AUC were simultaneously measured. Results: Data from 50 patients were analyzed. We demonstrated moderate correlations between SCI and intellectual task performance (POD1: Spearman-rank correlation coefficients 0.31 ≤ r ≤ 0.45; 0.001 ≤ p ≤ 0.03. POD2: 0.48 ≤ r ≤ 0.58; p < 0.0001), but weak correlations between SCI and anxiety (POD1: 0.23 ≤ r ≤ 0.31; 0.03 ≤ p ≤ 0.11. POD2: 0.07 ≤ r ≤ 0.11; 0.45 ≤ p ≤ 0.65) or nausea (POD1: -0.009 ≤ r ≤ 0.09; 0.54 ≤ p ≤ 0.98. POD2: 0.09 ≤ r ≤ 0.21; 0.14 ≤ p ≤ 0.53), with cut- off values used in our study population. Conclusions: Skin conductance indices may be influenced by intellectual task performance of the patient during the measurement of NFSC. In our study, there was no influence of anxiety or nausea on SCI. Further studies are required to determine the cut off values that will best predict the sensitivity and specificity of skin conductance for monitoring acute pain and other emotional stressors.

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GLOBAL PATIENT SATISFACTION OF IV ACETAMINOPHEN: AN INTEGRATED SUMMARY OF RANDOMIZED, PLACEBO-CONTROLLED, REPEATED-DOSE STUDIES OF ACUTE PAIN IN ADULTS J. Portillo, P. Dalal, A. Uribe, S. Bergese The Ohio State University, The Ohio State University,, Columbus, Columbus, OH, USA Introduction:

Over the last few years, the Joint Commission and Medicare online quality comparisons have put an increasing emphasis on global patient satisfaction in the hospital setting since it could have an impact on reimbursement risks. Measures of global patient satisfaction with medications are utilized in clinical pain trials. Intravenous (IV) acetaminophen has been approved in the USAs for pain management and fever reduction (OFIRMEV®, Cadence Pharmaceuticals, Inc, San Diego, CA). While its safety and efficacy have been established, patient satisfaction is an important related endpoint and warrants an independent integrated summary and systematic literature review.

Methods:

Data from a total of five Cadence- or Bristol-Myers Squibb (BMS)-sponsored randomized, placebo-controlled, repeated-dose trials of IV acetaminophen for acute pain in adults were retrospectively pooled for an integrated summary of global patient satisfaction assessed at 24 hours using a 4-point categorical scale ranging from 0 = poor to 3 = excellent (Candiotti- 2008, Gimbel 2008, Minkowitz-2008, Sinatra-2005, and Wininger-2010). Aside from overall effects on patient satisfaction by treatment group using mean scores, frequency and percentages, sub-group analyses were performed looking at age category, gender, race, surgery type, baseline pain intensity, and the occurrence of adverse events (AEs).

Results:

A total of 717 patients received repeated doses of IV acetaminophen (n=351) or placebo (n=366). The integrated summary of global patient satisfaction across these studies showed a statistically significant difference (p< 0.001) favoring IV acetaminophen 1000 mg compared with placebo. Patient satisfaction was rated “excellent” or “good” in 78.7% of patients who received IV acetaminophen compared to 62.8% of patients who received placebo. Compiled results showed that 86% of patients were < 65 years of age (mean = 48 years), 83% were female, and 80% underwent abdominal or gynecological surgery. Satisfaction with study treatment was high in patients treated with IV acetaminophen compared with placebo regardless of age category (elderly [p=0.032]; non-elderly [p=0.001]), gender (male; female [both p< 0.001]), and whether or not the patient experienced an AE (p< 0.001 and p=0.001, respectively). IV acetaminophen showed better satisfaction in patients who were white (p< 0.001), underwent abdominal or gynecological surgery (p< 0.001) or hip arthroplasty (p=0.013), or with moderate (VAS 40-70) or severe (VAS >70) pain intensity scores at baseline (p< 0.001 and p=0.02, respectively). Global patient satisfaction was not significantly different between the IV acetaminophen and placebo groups in patients who were non-white, underwent knee arthroplasty, or had mild pain intensity [< 40] at baseline.

Discussion:

Results from the integrated summary of placebo-controlled repeated-dose studies and an additional 22 studies that assessed the impact of IV acetaminophen on patient satisfaction suggested that IV acetaminophen conferred a high degree of patient satisfaction, leading to important implications for hospital reimbursement and patient care decisions. A63

INFERIOR HYPOGASTRIC PLEXUS BLOCK EFFECTS THE S1, 2, 3 ANTERIOR NERVE ROOTS INSTEAD OF THE SYMPATHETIC CHAIN ACCORDING TO CADAVER STUDIES A. Stogicza, A.M. Trescot, E. Racz, L. Magyar, L. Lollo One Orthopedic Place, St Augustine, FL, USA, Anesth&Pain, Peterfy Hospital, Forensic sciences, Budapest, Hungary, University of Washington, Seattle, WA, USA Background

The inferior hypogastric plexus (IHP) is part of the sympathetic chain, but it is exceptional in its anatomic location; it forms a net, surrounding the pelvic organs, the rectum, the bladder, and the vagina. Pain from the lower abdominal, pelvic and perineal area is transmitted through the IHP. The IHP block is an occasionally performed procedure used to relieve pain of the pelvic structures. Such pain conditions include cancer and non-cancer related chronic pain of the rectum, anus, vagina, bladder, penis prostate, and perineum. The currently utilised, fluoroscopically guided technique involves a 22-gauge spinal needle passed through the posterior, then the anterior sacral foramen, to the anterior surface of the sacrum. Needle position is verified by contrast spread along the anterior surface of the sacrum; local anesthetic then is injected for diagnostic or therapeutic purposes.

Purpose

To identify the anatomic structures that are affected during an IHP block performed according to the currently recommended technique.

Hypothesis

The pain relief that patients achieve in pelvic pain conditions with IHP block is due to anesthesia of the anterior S1, 2, 3 nerve roots rather then the specific elimination of sympathetic mediated pain.

Methods

Five fresh, non-embalmed cadavers were placed in prone position, and an AP view was obtained with fluoroscopy. Slight cephalad tilt and lateral rotation enhanced the visibility of S2 foramen. The 22-gauge spinal needle was positioned through the posterior, then the anterior foramen to the ventral surface of the sacrum, as described by Schultz1. The needle position was verified with 5 cc of contrast, as it spread cephalad and caudad along the presacral plane. Then 10 cc of diluted methylene blue was injected to simulate the IHP block. The pelvic structures of the cadavers were then dissected to identify the dye spread.

Results

Three of the cadavers had bilateral dye spread with very similar 1-2 cm to the midline needle position. All the cadavers had similarly dyed tissues, which included the posterior surface of the rectum, but there was no anterior spread at all, and neither of the lateral aspect of the rectum, or other the pelvic organs were affected. The S1, S2, S3 anterior nerve roots were invariably affected. Cadavers #1, 2, and 3 showed bilateral contrast spread, involving S1, S2, S3 on the injected and S2, S3 on the non-injected side. Cadaver #4 and 5 showed unilateral staining of the S2, S3 anterior nerve roots. Each dissection showed blue staining of the superior hypogastric plexus, e.g at the anterior surface of the L5-S1 disc. Discussion

The IHP block is used in painful pelvic conditions where sympathetically maintained pain is thought to be a contributing factor. According to our cadaveric injections and dissections, the currently recommended technique allows local anesthetic spread to the anterior surface of the sacrum, posterior surface of the rectum, and the anterior sacral nerve roots, but not to the other pelvic organs, that are surrounded by the inferior hypogastric plexus. It is likely that the previously achieved success with this blockade is mostly the result of anesthetizing the S1, S2, S3 anterior nerve roots, and partly the superior hypogastric plexus, but not the IHP. As this trans-sacral injection consistently affected the superior hypogastric plexus, it may be another useful and technically easier technique to perform a superior hypogastric plexus block.

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NERVE LOCATOR MAPPER MAKES CONTINUOUS PERIPHERAL NERVE BLOCKADE EASIER IN ADULTS: A REVIEW AND PERSONAL OBSERVATIONS R. Anand, A. Aggarwal, K. Kumar Girdhar, A. Bhalotra, V. Saith, A. Misra, G. Manchanda Dept. of Anesthesiology & Intensive care & pain ma, Maulana Azad Medical College & Associated hospital, Dept. of Anesthesiology & Intensive care & pain ma, New Delhi, Dept. of Anesthesiology & Intensive care & pain ma, Maulana Azad Medical College & Associated hospital, Noida, India6Dept. of Anesthesiology & Intensive care & pain ma Maulana Azad Medical College & Associated hospital, New Delhi, India hospital, Delhi, India

Continuous peripheral nerve blockade provides excellent postoperative pain relief facilitating early ambulation and effective physiotherapy, thus minimizing postoperative ankylosis and incidence of CRPS especially followimg wrist surgeries. Various modalities have been advocated to improve the success rate of any peripheral nerve block. When using a peripheral nerve stimulator ( PNS), the tip of a stimulating electrode identifies the likely position of the nerve by evoking a characteristic muscle contraction at 0.5 mA when the tip of needle reaches within 1-2 mm of the nerve vicinity. However isolated use of peripheral nerve stimulator may require repeated needle passes due to anatomical variations. The use of ultrasound has the purported advantages of precise nerve location, shortened block procedure time and higher success rate with lesser amounts of local anesthetic. However, USG is in its infancy and literature related to nerve and nerve related injury remains sparse. USG is still not considered a gold standard modality. Also, the equipment used is expensive and often difficult to procure. Continuous needle visualization during real time USG is difficult to learn so success rate is still not 100% .

In a series of 20 patients undergoing peripheral limb surgeries we used a nerve mapper locator for continuous nerve blockade, thereby avoiding multiple pricks, reducing time to perform block and improving block success and patient acceptability.

We found that when using a percutaneous stimulator mapper, if a motor response is elicted at 3-5 mA output in case of supraclavicular and axillary brachial plexus blocks in the upper limb and femoral nerve blocks in lower limb in adults, close proximity of the nerve can be reasonably ascertained. This was followed by further precise localization with a stimulating electrode using an insulated needle with a conducting tip. There was no incidence of failed blocks. Further confirmation of the catheter tip was made using injection of non ionic dye and image intensifier which is easily available in the orthopedic suite. Most trials conducted have compared USG technique with PNS without additional use of a nerve mapper. Trials comparing USG with nerve mappper locater are lacking. Nerve stimulation relies on a visual motor and sensory end point which is a physiologic response rather than just by anatomic location as anatomic variability can produce confusion Lack of physiologic response and anatomic clarity has lead to inadvertent peritendonous delivery of local anesthetic with subsequent block failure when using USG. Thus the use of a nerve mapper locator may be associated with a shortened block procedure time, reduced number of needle passes to target and is a low cost and easy to learn technique which does not require the extensive training necessary with ultrasound.

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A COMPARISON BETWEEN COMBINED SPINAL-EPIDURAL ANESTHESIA (CSE) WITH OR WITHOUT EPIDURAL SALINE ADMINISTRATION .FOR C/S P. Patel, S. Cohen, S. Shah, M. Rao, M. Fenandez, R. Chhokra, S. Barsoum, J. Tse, C.W. Hunter Anesthesiology, UMDNJ-Robert Wood Johnson Medical School, Anesthesiology, New Brunswick, 4Anesthesiology, UMDNJ-Robert Wood Johnson Medical School, UMDNJ- Robert Wood Johnson Medical School, New Brunswick, UMDNJ-Robert Wood Johnson Medical School, New Jersy, NJ, USA Introduction: Epidural administration of local anesthetic solution for C/S by gravity via the needle is associated with higher success rate, fewer paresthesias, and fewer epidural blood vessel punctures than the traditional injection through the epidural catheter(1). Objective: To determine whether administration of saline by gravity via the epidural needle into the epidural space after intrathecal injection of local a. and before epidural catheter insertion is associated with fewer adverse effects. We conducted, with IRB approval, a prospective, randomized, double-blind study of 128 consenting parturients who received CSE for elective C/S. Methods: In all patients the epidural space was located at L4-5 or L3-4 interspace using epidural needle in lateral decubitus position. Group I (n=64) the catheter was inserted immediately following administration of spinal solution via PENCAN 25g needle (B. Braun Medical Inc). Group II (n=64) 10 ml saline was administered by gravity into the epidural space following spinal solution injection. B. Braun closed-end catheter was then inserted 5 cm epidurally. All patients received 10mg ropivacaine with 100mcg epinephrine and 25mcg fentanyl intrathecally. Increment epidural doses of 5-20ml of 0.75% ropivacaine with 5mcg/ml epinephrine & 5mcg fentanyl were administered when spinal anesthesia was unsatisfactory. Twenty minutes after the start of the injection, the investigator recorded the following patient data: height, weight, parity, gestational age, APGAR score, the distance of the epidural space from the skin, history of previous epidural block, spinal block, spinal tap, dural puncture, blood patch, the ability of the anesthesiologist to pass the catheter on the first attempt without manipulation, the appearance of frank blood or CSF in the catheter, and the presence of paresthesia with or without involuntary parturient leg movement. The catheter was observed for blood return both passively and after the application of negative pressure. If the parturient does not volunteer any symptoms or signs of paresthesia, she was then asked directly by observer. The sensory level was assessed with skin application of ice. The degree of motor blockade was assessed by modified Bromage test (1=no foot movement, 5= complete hip and knee flexion). Since the degree of motor block could be asymmetrical, both legs were assessed and the greatest degree of motor block in either leg was used in further analysis. When needed, additional local anesthetic solution was injected via the epidural catheter to achieve a satisfactory block. Upon arrival at PACU and after a negative aspiration test, 3 ml 1.5% lidocaine with epinephrine 5µg/ml was injected via epidural catheter. Following a negative test dose, the epidural catheter was connected to a portable Abbott Pain Management Provider (Abbott Laboratories North Chicago, IL 60064) for post C/S pain management. Patients were contacted by phone for week for possible complications of post dural puncture headache and transient radicular irritation. Results: Values are mean + SD. Groups did not differ in age, height, parity, duration of surgery, incidence of itching, sedation, hypotension or APGAR scores. There were 13 pt's in GI & 19 pt's in GII for whom S/A block was u

Conclusion: These data show that epidural administration of 10ml saline by gravity before insertion of epidural catheter for CSE for C/S has a higher success rate, better quality of anesthesia, fewer epidural vessel puncture & fewer paresthesias than CSE without epidural saline administration. Reference 1. S. Cohen et al. Anesth Analg 86:5364, 1998 A66

HAMSTRING DONOR-SITE BLOCK FOR PAIN CONTROL AFTER ACL RECONSTRUCTION J. Tawil, K. Schroeder, M. Donnelly, B. Anderson Anesthesiology, University of Wisconsin, Anesthesiology, Madison, Madison, WI, USA Hamstring Donor-Site Infiltration for Pain Control After ACL ReconstructionIntroduction: Perioperative pain associated with the hamstring donor site harvest is a common problem for outpatients following Anterior Cruciate Ligament (ACL) repair. Our institution typically provides femoral nerve blockade for these procedures. However, this block does not provide complete analgesia for posterior knee or hamstring donor site pain. While sciatic nerve blockade is an effective therapy for treating this residual pain, it is often not performed for a variety of reasons. Local infiltration has been a valuable technique for control of pain related to other orthopedic procedures. We have instituted a practice of infiltration of local anesthetic along the hamstring tendon donor site during ACL repair.Methods: Following IRB approval, data from 21 consecutive patients undergoing outpatient ACL repair with hamstring autograft were collected. Data were collected on intraoperative and PACU narcotic administration, nausea, rate of hospital admission and pain scores in recovery phases one and two, as well as times to discharge and complications. Patients with femoral nerve catheters or incomplete data related to pain scores were excluded from analysis. There were no exclusions based on patient factors including (age, sex, ASA score, or other comorbidities). The local infiltration was performed with 20 ml of 0.125% bupivacaine injected along the tract of hamstring graft harvest. This was done by injecting local anesthetic with a slip tip catheter through a pediatric red rubber Foley catheter styleted with a disposable ETT stylet. Femoral nerve blocks were performed preoperatively with variable volumes of either bupivacaine 0.25% or 0.5% with or without epinephrine. All femoral nerve blocks were placed with nerve stimulation and ultrasound guidance; LMAs were placed for operative airway management in all patients. A numerical pain scale was used for evaluating pain scores where 0 represents no pain and 10 represents the worst pain imaginable. There was no standardization of intraoperative pain management.Results: Baseline characteristics between groups were not statistically significant when calculating two tailed Student T testing. Figure 1

Local anesthetic dosing and non narcotic drug dosing were similar between groups. PACU stays, narcotic use and pain scores did not differ significantly.

[2120411145625Figure_2.doc]

Discussion: This study suggests that there are no differences in any of the measured variables between groups. The trends even seem to suggest that increased pain was noted in the infiltration group. This may represent a bias towards performing this block in patients deemed to be more challenging from a pain management perspective. This study is clearly limited in that it is a non-randomized, retrospective chart review and therefore future controlled studies may be warranted. The number of patients in this study is also low and further randomized larger scale trials are warranted before the debate on this procedure can be closed.

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UNRAVELING THE ENIGMA OF CHRONIC PELVIC PAIN J.S. McDonald, J. Li, A. Rapkin, V. Chaban, P. Micevych Anesthesiology, Harbor-UCLA Medical Center, Torrance, Ob/Gyn, UCLA, Internal Medicine, Los Angeles, Neurobiology, UCLA, Los Angeles, CA, USA Introduction: Studies suggest that syndromes such as IBS are often comorbid with chronic pelvic pain in women. The possible explanation is visceral-visceral cross-sensitization. This abstract is the combined results of 5 years of both basic science and applied clinical research to examine responses at DRG neurons innervating viscus for possible mechanisms involving chronic pelvic pain.

Methods: DRG neurons were retrograde labeled by injecting fluorescences into colonic and uterine wall. Inflammation was induced by injecting mustard oil into uterine lumen in rats. DRGs of L1-S3 were cut at 20 µm thick, incubated in antibody for pERK and SP. The number of pERK or SP positive neurons was counted under fluorescent microscopy. DRG neurons were also acutely isolated by enzyme and cultured for calcium imaging stimulated by ATP and its modulation by estradiol and mGluR(2/3) inhibitor LY341495.

Results: 1. 7% DRG neurons were colon-specific, 11% uterus-specific, and 3% neurons innervating both uterus and colon.

2. Inflammation increased pERK and SP immunoreactivity in DRG neurons innervating both uterus and colon.

3. Estradiol attenuated ATP-induced intracellular calcium increase in 60% of DRG neurons. Co-application of estradiol and mGluR (2/3) inhibitor LY341495 blocked estradiol attenuation of ATP-induced intracellular calcium increase.

Conclusions: 1. DRG neurons innervating both uterus and colon were identified.

2. Inflammation increased immunoreactivity of pERK and SP in DRG neurons innervating both uterus and colon.

3. The rapid action of estradiol in DRG neurons involves interaction with mGluRs.

4. Results suggest visceral sensory integration in DRG may underlie comorbidity of chronic pelvic pain in women. References:

1. Latthe P, Mignini L, Gray R, Hills R, Khan K. Factors predisposing women to chronic pelvic pain: systematic review. BMJ. 332:749-55, 2006.

2. Friedrich-Karl Pierau, Gerd Fellmer and David C. M.Taylor . Somato-Visceral Convergence in Cat Dorsal Root Ganglion Neurones Demonstrated by Double-Labelling With Fluorescent Tracers. Brain Research, 321: 63-70, 1984.

3. Guang-Yin Xu and Li-Yen Mae Huang. Peripheral Inflammation Sensitizes P2X Receptor- Mediated Responses in Rat Dorsal Root Ganglion Neurons. The Journal of Neuroscience, 22(1): 93-102, 2002

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CAN LOCOREGIONAL ANESTHESIA FOR LUNG CANCER SURGERY AFFECT EVOLUTION OR MORTALITY? A. Hassen, D. Mathieu, D. Hervé Intensive care and anesthesiology, Assistance publique-Hôpitaux de Paris, Henri MONDOR teaching hospital, Créteil, Amiens University Hospital, Amiens, France Introduction:

Regional anesthesia would reduce the recurrence and metastasis after cancer surgery. Lung cancer is the first cause of cancer death in France and worldwide. The aim of our study was to evaluate the influence of anesthesia after lung cancer surgery.

Materials and methods:

Retrospective study of 109 patients who underwent pneumonectomy or lobectomy in 2008 and 2009 at the University Hospital of Amiens. Fifty eight cases were complete and have the criteria for inclusion and non inclusion. Survival curves were obtained using the Kaplan- Meier curves and comparison was made with the log-rank test.

Results:

The average follow-up was 23 months.

40 patients had received regional anesthesia (RA) and 18 had general anesthesia (GA) alone.

The anesthesia did not appear to influence survival or the occurrence of metastasis in patients operated for Non-Small Cell Lung Cancer (NSCLC).

More than half of patients (53.4%) received postoperative analgesia with morphine pump, 35% in the LR group and 94% in the GA group (p = 2.10-5).

Conclusion :

This retrospective study did not find influence of anesthesia on the evolution of NSCLC surgery followed for 23 months. These results require confrontation with prospective, randomized with a larger number of patients.

Keywords:

Non-Small cell Lung Cancer, regional anesthesia, epidural anesthesia, mortality, tumor metastasis, recurrence.

[1121811073758Characteristics_of_.pdf]

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ULTRASOUND GUIDED IMPLANTATION OF PERMANENT PERIPHERAL NERVE STIMULATOR FOR TREATMENT OF POST-AMPUTATION PHANTOM PAIN C.J. Hurt, W.T. Lennard, S.R. Hanling, I.K. Lesnik Department of Anesthesiology, Naval Medical Center San Diego, San Diego, Department of Anesthesiology, Naval Medical Center San Diego, Ban Diego, CA, USA A 26 year old previously healthy male US Navy sailor suffered multiple extremity injuries, to include multiple right foot metatarsal fractures, right distal tibia fracture, left calcaneal and fibula fractures, and right ulna fracture, as well as a traumatic brain injury (TBI) due to a roadside improvised explosive device (IED) which detonated while a passenger in a HUMVEE while deployed to Operation Iraqi Freedom (OIF 2006). Over the course of his treatment, he ultimately required a left lower extremity below-the-knee amputation(BKA) secondary to failed limb salvage therapy in 2006. Post-operatively, he began to experience arthralgic left knee pain due to degenerative joint destruction (DJD), marked stump pain aggravated by prosthesis use, and phantom limb pain. After failing initial medical management, he was referred to Pain Medicine in 2009. During the course of his workup and treatment with the pain clinic, he underwent many successful trials of therapy, to include femoral and sciatic peripheral nerve catheters, ultrasound guided pulsed radiofrequency therapy of the sciatic and saphenous nerves, and lead placement trial of ultrasound guided peripheral nerve stimulator of the saphenous nerve. These therapies led to placement of a permanent peripheral nerve stimulator via ultrasound guidance initially directed toward the saphenous but ultimately directed toward an anterior cutanous branch of the femoral nerve in order to avoid motor stimulation of the sartorius and vastus medialis. As a result of this interventions, the patient was able to have restoration of full function and tolerance of his lower extremity prosthesis. This has resulted in his return to full duty in the US Navy, and additionally to his participation in try-outs for the US 2012-2013 Para-Olympic Volleyball Team.

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PHRENIC NERVE PARALYSIS FOLLOWING INTERSCALENE BRACHIAL PLEXUS CATHETER J.L. Baratta, G. Hsu, K. Gandhi Dept of Anesthesiology, Jefferson Medical College, Philadelphia, PA, USA We describe a case of a 63 y/o female with history of right shoulder osteoarthritis presenting for right total shoulder arthroplasty. Past medical history includes Parkinson's disease and right breast cancer status post mastectomy and chemotherapy with residual right upper extremity lymphedema. Patient also reported pre-existing numbness and weakness of the right arm. She denied preexisting respiratory distress. After discussion of risks and benefits, an interscalene brachial plexus catheter (ISBPC) was planned preoperatively under ultrasound guidance and nerve stimulation for postoperative pain control.

With continuous pulse oximetry and intermittent blood pressure monitoring, the patient received 5 mg of midazolam incrementally for conscious sedation and remained easily arousable with saturations greater than 95% on room air. Under continuous ultrasound guidance, the brachial plexus was identified in the interscalene groove and an 18G, 2 inch Tuohy stimulating needle was inserted via an in-plane, posterior approach. With continuous visualization, the needle was adjusted until deltoid contraction was achieved via nerve stimulation. 30 mL 0.5% ropivacaine was injected incrementally under low pressure after negative aspiration of blood and without paresthesia. No diaphragmatic stimulation was observed. A 20g multi-orifice catheter was inserted. The patient had an uneventful surgery under general anesthesia in the beach chair position. In the recovery room, the ISBPC infusion was started with ropivacaine 0.2% at 10 ml/hr and continued 48 hours postoperatively.

Postoperative day one, the patient complained of dyspnea at rest and continued to require supplemental oxygen. Chest X-ray showed low lung volumes with elevation of the right diaphragm and patchy atelectasis of the right lower lung. At discharge, the patient's symptoms and chest X-ray had not improved. At 6 months postoperatively, the patient continues to have dyspnea requiring intermittent supplemental oxygen suggesting prolonged right phrenic nerve paralysis as a result of the ISBPC. At this time the patient refuses phrenic nerve conduction studies to confirm paralysis.

It is well-known that the incidence of temporary hemidiaphragmatic paralysis is approximately 100% following interscalene brachial plexus block (ISBPB) due to either spread of local anesthetic to the C3-C5 nerve roots or to the phrenic nerve in the anterior scalene fascia.1 To date there have been three published case reports of prolonged phrenic nerve paralysis following ISBPB, all utilized landmarks described by Winnie, while one confirmed location by paresthesia2 and the others used nerve stimulation3,4. Our case is the first of suspected phrenic nerve paralysis following continuous interscalene catheter placement under ultrasound guidance and nerve stimulation. Given the uneventful preoperative regional anesthetic technique, perhaps the patient suffered prolonged phrenic nerve paralysis because she was at increased risk of nerve injury secondary to the prior insult from right mastectomy and chemotherapy.

Ref:

1. Urmey W, etal. Anesth Analg 1991;72:498-03 2. Bashein G, etal. Anesthesiology 1985;63:102-4 3. Robaux S, etal. Anesthesiology 2001;95:1519-21 4. Ediale K, etal. J Clin Anesth 2004;16:573-5 A71

EMERGENT EPIDURAL BLOOD PATCH FOR PARADOXICAL CEREBRAL HERNIATION SYNDROME W. Shah, R. Abramov, K. Gandhi Anesthesia, Thomas Jefferson University Hospital, Anesthesia, Thomas Jefferson University, philadelphia, PA, USA Introduction: Paradoxical Cerebral Herniation (PCH) is a rare but potentially fatal syndrome caused by a lumbar CSF leak in patients after decompressive craniectomy1,2. Hemicraniectomy exposes the brain to atmospheric pressure (760 mmHg) and gravity, this invisible external mass effect, combined with a lumbar CSF leak (after lumbar puncture) can cause a negative pressure gradient caudally. This gradient can “paradoxically” cause a life threatening shift of tissue downward toward the foramen magnum, resulting in various types of cerebral herniation1,3,6. Our case highlights the importance of early recognition and treatment of this syndrome. Case: A 47 year old female underwent removal of a left spheno- orbital meningioma and lumbar drain placement. Post-operative day 1 was complicated by episodes of aphasia and mental slowing. An emergency CT scan of the head revealed left- sided hemispheric mass effect and left to right mid-line shift due to post surgical edema. The patient subsequently underwent an emergent left decompressive hemi-craniectomy and removal of lumbar drain. She was kept intubated and transferred to the Neuro-ICU for further monitoring. Her postoperative ICU stay was complicated by continued mechanical ventilation, unresponsiveness, decorticate posturing, and a sinking skin flap. PCH was now suspected and the chronic pain service was consulted to perform an emergent epidural blood patch. We elected to perform this procedure in the OR under fluroscopic guidance to ensure success. Within 3 hrs of the blood patch the patient was arouseable, following commands, extubated without incident and found to be at her pre-surgical baseline. Discussion: Hemicraniectomy exposes the cerebral surface to atmospheric pressure, making a “closed box” into an “open box.” This life saving procedure can relive the brain of dangerous increases in intracranial pressure, but opens it to unique and rare complications. With the CNS exposed to atmospheric pressure, a lumbar CSF leak from lumbar drain removal or even lumbar puncture can cause the development of a negative pressure gradient caudally, loss of ICP and life threatening tissue shifts1. Signs and symptoms include headache, acute mental status changes, obtundation, seizures, focal deficits, ominous posturing (decorticate/decerebrate), papillary changes, and depressed skin flap/duroplasty5,6.

In other reported cases an epidural blood patch was delayed or used as a secondary option when cranioplasty failed to reverse the paradoxical herniation3,4. Our case emphasizes the importance and immediate effects of an emergent epidural blood patch. Summary: Paradoxical herniation is a rare and potentially fatal syndrome that can occur in patients with craniectomy and a CSF leak. Quick recognition and first line treatment with an epidural blood patch can prevent permanent neurologic damage and provide rapid recovery. References:

1. Atkins PT et al. Neurocritical Care, 2008; vol 9: 269-267. 2. Sarov M et al. Stroke, 2010; 41: 560-562. 3. Seinfield J et al. Neurosurgery, 2007; Vol 61: 175. 4. Muehlschlegel S et al. Arch Neurology, 2009;66(5):670-671. 5. Voss HU et al. Clinical Imaging, July 2011; Vol 35: 253-258. 6. Vilela MD. Surgical Neurology, 2008; Vol 69: 293-296.

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POSTOPERATIVE ANALGESIC MANAGEMENT FOR A PATIENT UNDERGOING CADAVERIC HAND ALLOTRANSPLANTATION -- A CASE REPORT N. Dhamija, N.N. Patel, B.Z. Farrell Anesthesiology, Ronald Reagan UCLA Medical Center, Los Angeles, CA, USA Case: A 26-year-old, 86-kg, previously right-handed female underwent the first cadaveric right hand allotransplantation at the Ronald Reagan UCLA Medical Center. The patient had a history of an unsalvageable crush injury to her right hand requiring completion amputation five years ago. Subsequently, she developed phantom limb pain and required opioid, anti- epileptic and anti-neuropathic therapies for several months. Following physical therapy and right upper extremity desensitization, she acquired left-hand dominance. Nonetheless, she felt severe limitations performing routine activities and found prosthetic devices cumbersome. After a comprehensive, multidisciplinary preoperative evaluation, and availability of a compatible donor, the patient underwent this novel surgery by multiple orthopedic and plastic surgeons under general anesthesia. Prior to anesthetic induction, she received a right supraclavicular brachial plexus catheter with use of ultrasound and nerve stimulator (a 17- gauge stimulating needle was employed to detect biceps muscle twitch at 0.4 mA). The location of the catheter tip was confirmed by ultrasound with air and saline injection [Figure 1]. Intraoperatively, the patient received a total of intravenous (IV) fentanyl 550 mcg and hydromorphone 3.2 mg. Prior to emergence, she received perineural (PN) 5 mL ropivacaine 0.2%, 20 mL bupivacaine 0.25% with 1:200,000 epinephrine, and 10 mL of lidocaine 1%. She was extubated and transported to the intensive care unit in stable condition, with 0/10 pain on the visual analog scale (VAS). Results: Until postoperative day (POD) 3, the patient was placed on two modes of patient-controlled analgesia (PCA): (1) PN ropivacaine 0.2%, basal rate 8 mL/h, bolus 2 mL every 10 minutes and 6 boluses/h limit, and (2) IV hydromorphone, 0.2 mg every 10 minutes (no basal rate) and 4 boluses/h limit. Out of 67 hourly time-points spanning POD 0 to 3, she most commonly endorsed 0/10 pain (42 time- points) [Figure 2], with mean VAS of 1.31 ± 2.00. Out of 61 time-points, the mean hourly number of PN-PCA boluses were 1.45 ± 1.17 (attempted), and 1.16 ± 0.87 (received); she most commonly requested 2 boluses/h (20 time-points), and received 1 bolus/h (22 time- points) [Figure 3]. Out of 63 time-points, the mean hourly number of IV-PCA boluses were 1.14 ± 0.8 (attempted) and 1.09 ± 0.73 (received); she most commonly requested 1 bolus/h (32 time-points), and received 1 bolus/h (31 time-points) [Figure 4]. On POD 3, she was transitioned to oxycodone 5/10/15 mg every 3 hours as needed for mild/moderate/severe pain. Discussion: In spite of potential for significant postoperative pain, the use of continuous perineural ropivacaine infusion allowed our patient to have remarkably low analgesic requirements, obliterating undue side effects from high-dose narcotics. Our approach conferred graft immobility to maintain patency of neo-anastomoses between the host-graft vascular, muscular and nervous structures in the early postoperative period. Furthermore, this technique potentially augmented dilation of vascular anastomoses, enhancing long-term graft viability. Our case demonstrates efficacy of perineural catheters in management of postoperative pain in the future of composite tissue transplantation .

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EPIDURAL PLACEMENT FOR POSTOPERATIVE ILEUS A. Tahilramani, A. Upadhyay Anesthesiology - Pain ManagementAnesthesiology - Pain Management, Henry Ford Hospital, Anesthesiology - Pain Management, Henry Ford Hospital, Detroit, MI, USA Introduction:

We present a case of epidural catheter placement for analgesic purposes as well as subsequent resolution of ileus, in a patient presenting with severe postoperative opioid-induced ileus.

Case:

Patient presents as a 31 year old female with a history of ulcerative colitis treated with abdominal colectomy and ileostomy for toxic colitis. The patient underwent an ileal pouch- anal anastamosis with completion proctectomy. The patients' postoperative analgesic plan entailed a combination of parenteral and oral opiods. On postoperative day eight, the patient developed symptomatic small bowel dysfunction later to be diagnosed as severe postoperative ileus by CT scan. The bowel obstruction was treated with conservative measures, however the patient continued to complain of severe abdominal pain, subsequently requiring escalating doses of intravenous hydromorphone. On postoperative day twenty- eight, the acute pain service was consulted for management of narcotics. On physical exam, the patient's abdomen was extremely distended and tympanic. Epidural catheter placement with continuous epidural infusion of 0.125% Bupivicaine was recommended. An epidural was then placed at the T7-T8 level, which significantly reduced the abdominal distention as well as the amount of opioids required for pain control. On postoperative day thirty-three, the ileus completely resolved and the patient was able to tolerate oral intake. The epidural was then discontinued and the patient was discharged home on oral pain medication.

Discussion:

Postoperative ileus (POI), although attributable to surgical procedures, is frequently exacerbated by perioperative opioid use. The pathophysiology of POI is multifactorial, and includes the activation of inhibitory sympathetic reflexes, local and systemic inflammatory mediators, and inhibitory gastrointestinal peptides. Stimulation of sympathetic fibers inhibits gastrointestinal motility; therefore sympathetic hyperactivity associated with surgery is predominantly responsible for the development of a postoperative ileus. Opioid treatment for postoperative pain control is frequently associated with adverse effects, often times presenting as incapacitating bowel dysfunction. Activation of opioid receptors in the gastrointestinal tract combined with sympathetic hyperactivity inhibits GI motility further. Epidural anesthesia has been proven to provide a means to substantially reduce the amount of required postoperative opioids and will also block the sympathetic reflexes associated with abdominal surgery. The efficacy of epidural anesthesia is heavily dependent on location. Placement at the thoracic level supersedes low-thoracic or lumbar administration. Epidural with local anesthetic only or local anesthetic/opioid combination has shown to produce a more rapid recovery than opioid-only epidurals. In patients who undergo major abdominal surgery, postoperative thoracic epidural analgesia with local anesthetics maintained for 48 hours significantly reduces POI. The most important physiologic rationale for epidural blockade is the ability to block afferent input from the wound site and reduce sympathetic hyperactivity associated with abdominal surgery. A74

STELLATE GANGLION BLOCK AS THE FIRST BIOLOGIC TREATMENT ALTERNATIVE FOR POST-TRAUMATIC STRESS DISORDER: RESULTS AND POSTULATED MECHANISM OF ACTION FROM A RETROSPECTIVE CASE SERIES E.G. Lipov, M. Navaie, E.T. Stedje-Larsen, K. Burkhardt, J.C. Smith, L. Sharghi H., A. Hickey H. Advance Health Solutions, La Jolla, Anesthesiology, Naval Medical Center San Diego, san Diego, CA, Hoffman Estates, Hoffman Estates, IL, Anesthesiology Naval Medical Center San Diego, San Diego, CA, USA Introductions: Post-traumatic stress disorder (PTSD) is a chronic anxiety condition caused by experiencing traumatic events. Current treatments include pharmacotherapy and/or psychotherapy but efficacy rates are only between 20 to 30%. Recently, a biologic treatment alternative using a stellate ganglion block (SGB) has shown favorable results in three case reports. This study aims to build on these promising preliminary reports by further investigating the effects of SGB on various dimensions of PTSD and elucidating SGB's potential mechanism of action in relation to PTSD.

Methodology: A retrospective case series of patients (n=8) who received one (n=6) or more (n=2) SGB treatments using 1% lidocaine administered with fluoroscopic needle guidance for PTSD was identified at a private practice. A wide range of data was extracted from medical records including sociodemographics, treatment history, co-morbidities, medications, traumatic exposures including military combat, use of sedation, type and concentration of local anesthetics, adverse events and PTSD severity. T-tests were used to compare mean changes in PTSD severity scores, with p< 0.05 denoting significance.

Case Series Results: The majority of cases were male (88%), veterans (63%), and unmarried (63%). The average age across the series was 43 years (range, 29-66 years). Over 60% of patients were prescribed psychotropic medications and all had suffered from refractory PTSD for multiple years. Mean follow-up time after SGB treatment was 17 days (range, 1-59 days). Among the cases who received only one SGB, significant improvements in overall PTSD severity were observed (p=0.02) including symptoms related to PTSD dimensions of avoidance (p=0.03) and hyperarousal (p=0.01). On average, these patients experienced a 41% decrease in PTSD severity (range, 6-70%). Relative to cases who received one SGB, the two cases with multiple SGBs reported greater levels of relief (58.6% and 73.4%), with substantial improvements in all three PTSD-related psychological symptom clusters: re- experiencing, avoidance, and hyperarousal. No adverse events were reported.

Postulated Mechanism of Action: It appears that a deactivation of the sympathetic nervous system alleviates PTSD symptoms. Nerve growth factor (NGF) is likely to be key in explaining SGB's mechanism of action since NGF regulates a variety of signaling events such as cell differentiation and survival, growth cessation, and apoptosis of neurons. Mechanistically, the body responds to chronic and acute stress by increasing NGF levels, leading to retrograde transport from the intracerebral site to the stellate ganglia where sprouting of sympathetic neurons are increased. This results in elevated norepinephrine (NE) levels. Severe trauma may trigger this biochemical cascade which is ultimately responsible for PTSD. Reversal of this cascade can be achieved by local anesthetics applied to the stellate ganglion, which reduces NGF leading to the death of new sympathetic nerve shoots.

Conclusions: SGB shows promise as the first biologic intervention for the treatment of PTSD. Randomized trials are needed to generate robust evidence to expand SGB´s indication for the treatment of PTSD. A75

SUPRACLAVICULAR BLOCK IN A POST-LUNG TRANSPLANT PATIENT UNDERGOING OPEN REDUCTION AND INTERNAL FIXATION OF THE HUMERUS M. Koski, L. Mounir Soliman, J. Jerabek, J. George, W. Ali Sakr Esa Anesthesia Institute, Cleveland Clinic Foundation, Cleaveland, Anesthesia Institute, Cleveland Clinic Foundation, Anesthesia Institute, Cleveland, Cleveland, OH, USA Case: A 62 year old female, with multiple comorbidities, was scheduled for an open reduction and internal fixation of the left shoulder, after suffering a proximal humerus fracture. This patient has an extensive medical history: Severe COPD with history of a complicated left lung transplant in 2000, on home oxygen; ESRD, requiring hemodialysis; CHF, pulmonary hypertension, anemia and hypertension. Preoperatively, patient underwent an ultrasound-guided supraclavicular single shot nerve block to provide surgical analgesia to the left upper extremity. A total of 12.5 cc of 2% Mepivacaine and 12.5 cc of 1% Ropivacaine were injected, and carefully spread underneath and posterior to the plexus, in order to minimize anterior spread to the phrenic nerve. Shortly following the procedure, the patient had an excellent block to the left upper extremity. The anesthetic plan included monitored anesthesia care with a propofol/ ketamine (500mg/100mg) infusion at 7.5 cc/hr in combination with the supraclavicular block, and oxygen supplementation. The ORIF of the humerus was performed with the patient in the seated position and without complications. The post operative course and hospital stay were uncomplicated and satisfactory.

Discussion: Regional anesthesia was a major factor in the success of this surgery and post operative course. After a discussion among practitioners, it was decided that a supraclavicular block would provide the patient with the best analgesia and decreased risk of complications, as compared with an interscalene approach or general anesthesia. Common complications of supraclavicular blocks are local anesthetic toxicity, pneumothorax, subclavian artery puncture, and incidental phrenic nerve blockade. The phrenic nerve is almost always involved with interscalene blocks, and it is involved 50 - 67% of the time with supraclavicular blocks without ultrasound guidance. A recent study by Renes et al, comparing the incidence of phrenic nerve blockade in supraclavicular blocks using ultrasound versus nerve stimulation alone, resulted in complete phrenic nerve avoidance in the ultrasound group. In the event the phrenic nerve had been involved, the anesthetic plan would have resulted in general anesthesia, which was the original plan prior to the involvement of regional anesthesia. In avoiding general anesthesia with endotracheal intubation, complications including, inability to extubate and prolonged mechanical ventilation; worsening renal and cardiac functions, were avoided.

Conclusion: Recent advances in monitoring and methods of drug titration over the last few decades made general anesthesia very safe for most patients. However, this case demonstrates the value of regional anesthesia in patients who may be poor surgical candidates, secondary to co morbidities and the associated risks of general anesthesia. The choice of the appropriate level of the nerve block is crucial for the success of the block. The type of the surgical procedure, as well as the patient´s comorbidities must be considered when choosing the type of the block.

Renes SH, Spoormans HH, Gielen MJ, Rettig HC, van Geffen GJ. Hemidiaphragmatic paresis can be avoided in ultrasound-guided supraclavicular brachial plexus block. Reg Anesth Pain Med. 2009 Nov-Dec; 34(6):595-9.

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SEVERE PAIN FROM A PROXIMAL NERVE INJURY SUCCESSFULLY TREATED WITH A DISTALLY PLACED NERVE BLOCK R.J. Waclawski, R.J. Hackworth, J.M. Corey anesthesiology, Naval Medical Center San Diego, San diego, anesthesiology, Naval Medical Center San Diego, San Diego, CA, 2anesthesiology, Vanderbilt Pain Medicine, Nashville, TN, USA Introduction

Neuropathic pain is a complicated disease that has been extensively studied. One of the questions that exists with neuropathic pain processes is whether or not peripheral sensory input (of all types) plays a role in maintaining the persistent changes in the central nervous system and consequently, persistent pain. We demonstrate a case where a patient had a very proximal lesion causing severe and persistent pain manifested distally. However, by blocking the nerve distal to the lesion but proximal to the sensed area of pain, we were able to resolve the pain completely for the duration of the block.

Case Report

Patient was a 21 y/o female who had a gunshot wound to her right lower abdomen causing a suspected lumbar plexus injury. Imaging was limited to CT secondary to retained bullet fragments. Her primary complaint was pain in her right dorsal and plantar region of her foot and was described as a burning and throbbing sensation with extreme allodynia and she demonstrated an L3-L5 nerve injury with motor and sensory changes. She was started on an anti-epileptic, opioids and a tricyclic antidepressant. Despite aggressive medical management, she achieved only mild relief of her pain. A popliteal peripheral nerve catheter (PNC) with 0.2% Ropivicaine was then placed by the acute pain and regional service. The patient reported a decrease in her pain from 10/10 to 6/10. The concentration of ropivicaine was then increased to 0.3% with a decrease in her pain scale from 6/10 to 0/10. The complaints of pain, allodynia and hyperesthesia were successfully relieved.

The PNC was left in place from hospital day (HD) #6 through HD #14 with continued relief of her pain. Oral neuropathic pain medicines were titrated to higher doses in anticipation of transitioning her off her PNC. After discontinuation of her PNC, pain increased from full relief to 4-6/10, but she reported this was tolerable. She was discharged from the hospital and eventually underwent implantation of a dorsal column stimulator.

Discussion

The reasons for persistent pain in this setting are controversial and not well understood. Many investigators have tried to elucidate the mechanism and two predominant hypotheses have emerged. One ypothesis is that central sensitization is maintained independent of primary afferent input (1,2). Others maintain that continued peripheral input after reorganization and phenotypic switching of nerve fibers after injury drives postsynaptic pain (1,2). This second hypothesis has been demonstrated in an experimental model demonstrating necessity of afferent input(3). Investigators created a neuropathy by proximal nerve injury. They then blocked the sciatic nerve distally to the injury and showed a decrease in dorsal horn discharge. However, this idea is unproven in humans.

In our report, we show a case where proximal lumbar plexus injury that manifested itself in the distal foot was completely removed with a block distal to the injury site and persisted for days with the duration of the conduction block. Examples like these in humans are sparse in the literature, but this report yields additional evidence that normal peripheral input may help maintain a state of chronic neuropathic pain in humans.

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MYONECROSIS AFTER AN OCCIPITAL NERVE BLOCK M. Lanigan, N. Waghela, D. Elmofty Anesthesia and Critical Care, University of Chicago, Chicago, IL, USA Introduction: Corticosteroid and local anesthetic injections are frequently used as a method of pain management in several different disease processes including occipital neuralgia. This case report describes a patient who developed corticosteroid induced myonecrosis following an occipital nerve block with an injectate containing a corticosteroid and a local anesthetic.

Case report: A 26 year old female with a history of migraine headaches and left sided occipital pain that developed after a lipoma resection from the skull base presented for evaluation and treatment. The patient reported a longstanding history of migraine headaches occurring 2-3 times per week associated with blurry vision as a preceding aura. She described a constant sharp throbbing pain over the left occipital protuberance that had been worsening over the last year. She had an unremarkable brain MRI in 2010. A left sided occipital nerve block was performed using ultrasound guidance. Sonoanatomy was identified, including the occipital artery. A 4 ml solution containing 0.25% Bupivacaine and 40mg Triamcinolone was injected with a 22G 1 ½ inch needle. She reported 6 months of relief from her headaches and occipital pain. The patient returned to clinic 10 months later with a recurrence of her pain but noted a new deformity that she described as a “divot” over the base of her skull, at the location of the prior block. Upon referral to dermatology she was diagnosed with corticosteroid induced myonecrosis which was confirmed by MRI demonstrating atrophy of the left splenius capitus muscle. She received treatment with Botox injections and avoided further corticosteroid exposure.

Discussion: Corticosteroid induced myonecrosis is a rare reaction to corticosteroid therapy. There have been a few case reports of myopathy following corticosteroid therapy but these involve systemic corticosteroid therapy for neurologic pathologies. Myopathy is a known side effect of corticosteroids with an onset typically in weeks or months following chronic systemic corticosteroid therapy. Muscle biopsy typically shows non-specific selective atrophy of type I fibers. There have also been a few case reports of local anesthetic induced reversible myonecrosis following local anesthetic intramuscular injections. Muscle biopsy typically shows lytic degeneration of striated muscle sarcoplasmic reticulum, myocyte edema and necrosis. Muscular regeneration typically occurs within 3-4 weeks. We report a case of 26 year old patient developing localized myonecrosis after a localized corticosteroid and local anesthetic injection which was eventually treated with botox injections and avoidance of corticosteroids.

References:

Ojeda VJ. (1982) Pathology 14: 435-8.

Guis et al. (2003) Best Practice & Research Clinical Rheumatology 17(6): 877-907.

Zink et al. (2004) Regional Anesthesia and Pain Medicine 29(4):333-340.

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HARLEQUIN SYNDROME PROMPTING EARLY DISCONTINUATION OF FUNCTIONING EPIDURAL R. Derby, D. Auyong Anesthesiology, Virginia Mason Medical Center, Seattle, WA, USA A 61 y/o, 81 kg ASA II male underwent uncomplicated open cholecystectomy under general anesthesia and thoracic epidural. An infusion of bupivacaine 0.05% + hydromorphone 10 mcg/ml was initiated in PACU. On POD 1 the patient noted profuse sweating of the left side of his face and upper torso, saturating his sheets. On exam, the patient was warmer to touch with notable facial flushing on his left that was absent on the right (Fig1). The patient had diminished temperature sensation to ice from T2-T8 on his right side with no temperature distortion on the left, indicating a unilateral epidural block. Sensation, strength, and sweating of his right arm and other areas of his body were otherwise normal. Also notable was the lack of ptosis or myosis suggestive of Horner's syndrome. The profuse sweating persisted through POD2, and despite good analgesia, we discontinued his epidural the afternoon of POD2 at the patient's request. All symptoms resolved within 12 hours of discontinuing the epidural. The term “Harlequin syndrome” was first used by Lance et al(1) to describe the sudden onset of unilateral, well demarcated, facial flushing and sweating experienced by a series of patients after strenuous exercise, stressful emotion, or hot temperatures. It has since been recognized in acquired and congenital sympathetic dystrophies related to trauma, stroke, and tumors. It is regularly associated with idiopathic hyperhidrosis and is thought to be secondary to a disturbance of the sympathetic sudomotor (sweat gland innervation) and vasomotor fibers to the face. These pre-ganglionic fibers exit the spinal cord at T2 and T3 synapsing with post- ganglionic fibers in the superior cervical ganglion that bring ipsilateral innervation to the face. Therefore, blockade of these fibers from local anesthetics can cause a disruption of the sympathetic outflow to that side of the face. Harlequin syndrome is commonly experienced after endoscopic T2-T4 sympathetic chain clipping for hyperhidrosis. 76% of these patients report compensatory contralateral sweating in the non-affected side suggesting that the cause of increased flushing and sweating is from properly functioning sympathetic fibers in response to sudden denervation of the opposite side(2). Harlequin syndrome can be associated with regional anesthesia and has been reported with concurrent Horner's syndrome(3). Horner's syndrome, blockade of the pupillo-cilliary sympathetic fibers to the eye, derives from T1 fibers. In this patient, the limit of the epidural blockade was T2 and therefore spared the pre-ganglionic fibers implicated in Horner's. The patient's symptoms were a result of left-sided unilateral sympathetic blockade to T2 (but not T1) with contra- lateral compensatory sympathetic discharge. If the epidural spread had been bilateral, this unilateral sweating would not have occurred. Therefore, appropriate management of profuse sweating symptoms would be to withdraw the epidural catheter 1 to 2 cm to achieve bilateral spread or decrease the infusion rate to restrict epidural spread to below T3 spinal level. References:

1. Lance JW, J Neurol Neurosurg Psychiatry. 1988; 51:635-42.

2. Vanderhelst E, J Laparoendosc Adv Surg Tech. 2011 Dec; 21(10):905-9.

3. Burlacu CL, Br J Anaesth. 2005 Dec; 95(6):822-4.

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ACCIDENTAL EPIDURAL ADMINISTRATION OF BUFFERED HYPERTONIC SALINE 3% FOR POSTOPERATIVE ANALGESIA BY THORACIC EPIDURAL PCA L. Lester, J.C. Brookman Anesthesiology and Critical Care, Johns Hopkins University School of Medicine, Baltimore, MD, USA A 63 year old female underwent endoscopy and Laparoscopic Nissen for refractory gastroesophageal reflux. Anesthesia was accomplished with general endotracheal anesthesia (GETA) and epidural analgesia with 0.1% bupivicaine infusion with adjunctive fentanyl. Post-operative pain control with epidural patient controlled epidural analgesia (PCEA) was planned, and bupivicaine 0.125% at 4 mL/h continuous infusion with a demand dose of 2 mL/h, a 10 minutes lockout, and maximum of 6 doses/h was ordered. The patient received a total of 18.5 ml over approximately 3 hours, when it was discovered that 3% buffered hypertonic saline was being administered. The infusion was stopped and the patient evaluated. Her pain was 2/10 and she reported that she had never been so comfortable after any previous surgeries. She denied back pain greater than her baseline, and had no neurological symptoms by history or examination. Thirty minutes after the hypertonic saline infusion was stopped, her pain had increased to 7/10. Her epidural was flushed with 5 mL of Normal Saline, then 5 mL of lidocaine 1% was given before restarting the infusion at the above settings with bupivicaine 0.125% by PCEA, resulting in excellent pain control. The remainder of her hospital stay remained uneventful, and she had no neurological complications. In this patient, 3% buffered hypertonic saline appeared to have analgesic properties. Epidural and intrathecal administration of hypertonic saline in concentrations ranging from 7.5-20% have been described in the pain literature for analgesia and epidural lysis of adhesions. One previous study describes the accidental administration of 3% hypertonic saline for epidural lysis of adhesions. This is the first case report of accidental epidural administration of 3% buffered hypertonic saline. Further investigation of the analgesic efficacy and safety of epidural buffered hypertonic saline may be warranted. A80

SPINAL CORD STIMULATION FOR INTERCOSTAL NEURALGIA IN A PATIENT WITH IMPLANTABLE CARDIAC DEFIBRILLATOR AND BIVENTRICULAR PACING P. Gulur Massachusetts General Hospital, Boston, MA, USA Introduction:

With extended clinical indications of SCS for patients with chronic pain including angina pectoris or intercostal neuralgia , the co-existing indication for an AICD and/or pacemaker is becoming increasingly likely. While there are some reports of successful implantation of both these devices in patients with low back or lower limb pain, the SCS leads in these cases are usually low thoracic in location. To cover the intercostal neuralgia this patient suffered secondary to his thoracoscopic epicardial ventricular lead placement, this case report provides evidence that an octrode lead placed at T6 was compatible with the patients AICD and Biventricular pacing.

Case report:

A 39 year old male was diagnosed in April 2008 with severe cardiomyopathy, congestive heart failure, left bundle branch block and ventricular tachycardia and atypical chest pain. An ICD Medtronic Consulta Model D224TRK was placed but an attempt at a biventricular lead was unsuccessful due to challenging coronary sinus anatomy. Video-assisted thoracoscopic surgical placement of a left ventricular epicardial lead was then performed in Sept 2009. He complained of severe pain after surgical epicardial lead placement , described as deep in the left chest and stabbing, especially acute with deep inspiration and was found to have intercostal neuralgia.

A spinal cord stimulator trial was performed in October 2010. It was performed with anesthesia montioring. External defibrillator pads were placed on the patient and his AICD andpacemaker were montiored. A Medtronic octrode lead was introduced into the epidural space under fluoroscopic guidance with the tip of the lead advanced to the upper edge of the T6 vertebra. A trial stimulator provided adequate coverage of the painful area.. Monitoring of the patient´s AICD sensing signal showed no interference when the spinal cord stimulator was activated and used at different frequencies .The trial was successful. He underwent uneventful permanent implantation of a Medtronic prime ADVANCED spinal cord stimulator late Oct 2010 where we followed the same precautions as at the trial. The pulse generator delivered a continuous burst of stimuli at a fixed rate of 80 pulses per second. The patient was followed closely over the next few months and both devices continued to function in an optimal fashion.

Discussion:

The introduction of SCS has extended the treatment of severe pain in patients with intercostal neuralgia and angina pectoris. Stimulating the spine at the thoracic or cervical level of the dorsal column has been reported to reduce pain effectively in hitherto untreatable patients. In the literature there have been reports on simultaneous implantation of cardiac pacemakers and SCSs, which can safely be performed if certain precautions are carefully followed.However, experience in patients with spinal cord stimulation for intractable pain due to angina pectoris or intercostal neuralgia where the SCS leads are placed higher in the thoracic spine and therefore more prone to AICD interference due to close electrical fields are lacking. Other considerations such as potential for damage to the SCS from after shocks has to be considered.. To date, damage of the system after shock deliveries has not been reported.

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EXTENSIVE SUBCUTANEOUS HEMATOMA AFTER CERVICAL EPIDURAL STEROID INJECTION S. Patil, H. Benzon, R. Bell Anesthesiology, Northwestern University, Chicago, IL, USA Cervical epidural steroid injections are frequently performed with minimal complications (1). We found no other case report of extensive subcutaneous hematomas associated with a cervical epidural steroid injection.

Case: A 34 year old healthy man presented to our pain clinic with left shoulder and hand pain. He has a history of chronic left shoulder tic disorder treated the past year with botox injections. The pain was a constant aching pain with radiation to the left upper arm. Physical examination demonstrated decreased sensation over the left arm/forearm and decreased interossei strength. His MRI showed a small right foraminal disk protrusion at C6-7. One week later, he received a cervical epidural steroid injection at C7-T1 with a 20 G Touhy needle. No complications were noted - and he was discharged home in good condition. He returned five months later reporting 90% pain relief for four weeks with 40% residual benefit. He reported no adverse events from injection. We repeated the C7-T1 cervical epidural steroid injection with 17 G Tuohy needle wherein an epidural catheter threaded to the upper border of C6. No immediate complications noted and he was discharged in good condition. Ten days later, he noted swelling of his left neck. He went to the ER where he was afebrile with a normal WBC count. A CT scan showed low attenuation in the intermuscular fascial planes of the left neck but no discrete fluid collection was identified. He received IV Unasyn and was discharged home on oral Augmentin. The next day, the swelling increased with visible bruising. He called and we saw him in clinic that day. He was afebrile with ecchymosis over his left neck (Figure 1). An MRI showed a 12.1 cm x 2.1 cm multiloculated fluid collection under the left trapezius and levator scapulae muscles to the left fifth rib; largest accumulation at the C7-T1 level but no extension to the epidural space (Figure 2). ENT attempted drainage in the ER but was not successful. He was admitted and remained afebrile with normal WBC and coagulation labs. Three days later, he underwent an ultrasound-guided drainage of the mass and 30 mL of dark red viscous fluid was aspirated. The fluid contained red blood cells with no growth on aerobic/anaerobic cultures. One week later, he returned to clinic with improvement in the neck ecchymosis but with extension of his hematoma down the muscular fascial planes (Figure 3). A battery of laboratory tests were done: PT, PTT, INR, clotting factors VII, VIII, IX, XI, vWF, ANA, Anti-Jo-1 antibody, Anti- Scl-70 antibody, anti-Ro/SSA, anti-La/SSB, and an ESR. All were normal. One month later, an MRI/MRA of his neck was done which showed normal vasculature and marked improvement of fluid collection. At present, the patient recovered fully with no sequelae and no further issues with bleeding.

Discussion: We present a case of an extensive subcutaneous hematoma after a cervical epidural steroid injection. Extensive workup showed no abnormality. We plan to order a CT scan with infusion after the hematoma has completely resolved to detect any aberrant vessels in the area.

1. Rowlingson JC, Kirschenbaum LP. Anesth Analg 1986; 65: 938-42

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CAPSAICIN (QUTENZA) 8% PATCH ALLEVIATES PAIN AND ALLODYNIA IN A PATIENT WITH NEUROPATHIC PAIN INVOLVING AN OLD THORACOTOMY SCAR O. Eydlin, L. Daiana Voiculescu New York University School of Medicine, New York, NY, USA Introduction: Capsaicin (Qutenza) 8% patch is indicated for the treatment of neuropathic pain associated with postherpetic neuralgia. Capsaicin, a substance naturally found in chili peppers, is an agonist at the Transient Receptor Potential Vanilloid 1 (TRPV1) receptor. Nociceptive nerve fibers in the skin selectively express this ion channel-receptor complex. Capsaicin initially enhances TRPV1 stimulation and then reduces TRPV1-expressing nociceptors, which relieves pain. Neuropathic pain is a result of damage or pathology in the peripheral and/or central nervous system. This condition may become chronic and is often difficult to treat. Case Presentation: A 65-year-old man with a history of left lower lobectomy for persistent pneumonia in 1980 presented with severe, sharp, burning pain and paresthesia around the thoractomy scar for one year. The pain was exacerbated by inspiration, coughing, laying supine and cold weather. He described the pain intensity as 7-10/10 on an 11-point scale and denied radiation of pain from the scar site. He also experienced difficulty breathing and sleeping due to excruciating pain at night. Physical exam revealed an old, well-healed thoracotomy scar from T4-T10 that was positive for allodynia and paraesthesia, as well as multiple tender points along the scar. No neuromas were identified. Neurologic exam demonstrated decreased sensation to light touch around the scar and no other focal deficits. MRI was negative. The patient attempted numerous treatments in the past that provided no relief, including pregabalin, lidoderm patches, tizanidine and fentanyl patches. Trigger point injections with bupivacaine and lidocaine along the scar on two separate occasions provided moderate pain relief, but the pain returned one day after the injections with greater severity. Acetaminophen-hydrocodone resulted in some symptom improvement but was intolerable due to drowsiness and poor concentration. Decision was made to apply capsaicin 8% patch. The patient was pre-medicated with lidocaine 4% cream (applied over the painful area for one hour) and tramadol/apap 37.5/325 mg, 2 tabs PO, to reduce the discomfort associated with capsaicin application. Two capsaicin 8% patches cut to the scar shape were applied for one hour. The patient experienced two subsequent days of increased, burning pain, which gradually subsided to 0/10 pain with no allodynia over two weeks. At one year follow-up, the patient has remained completely pain- free with no allodynia. He has been off all analgesic agents.

Discussion: Capsaicin 8% patch may be useful for other neuropathic pain syndromes apart from postherpetic neuralgia; however, further studies are warranted to elucidate the full potential of this alternative treatment. We present a case of a patient with complete amelioration of pain and allodynia after one application of capsaicin 8% patch. In a patient who has failed multiple therapies for neuropathic pain, capsaicin 8% patch should be considered as a possible treatment option.

References: Anand P., Bley K. Topical Capsaicin for Pain Management: Therapeutic Potential and Mechanisms of Action of the New High-concentration Capsaicin 8% Patch. British Journal of Anaesthesia. 2011;107(4):490-502.

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CATHETER INJECTION OF PLATELET CONCENTRATE PRIOR TO REMOVAL OF A LUMBAR PLEXUS BLOCK IN THE SETTING OF BLEEDING DIATHESIS— A NOVEL INTERVENTION T. Sharma, K. Boddu Department of Anesthesiology, University of Texas Health Science Center Houston, epartment of Anesthesiology, University of Texas Health Science Center Houston, Houston, TX, USA Platelets play a crucial role in primary hemostasis, the initial formation of clot formation when damage to the endothelium of blood vessels occurs. This significance is most appreciated in the example of patients with thrombocytopenia as these patients are at risk of spontaneous bleeding. In the case presented in this report, a patient with a retained lumbar plexus catheter and a newly placed cardiac stent on clopidogrel and aspirin posed an interesting complexity of care. As it is known, clopidogrel irreversibly inhibits platelet action and thus discontinuing clopidogrel and removing the catheter, as might be the case for a patient on heparin or warfarin, was not a feasible action with concern of bleeding diathesis. A review of current literature suggests new and novel applications of platelets in managing disease. As a novel approach, in this case a concentrated aliquot of donor platelets followed by 8,000 units of recombinant thrombin were injected into the catheter followed by catheter removal. The patient was reassessed and monitored closely over the following days. The procedure carried no recognizable complications without evidence of bleeding, hematoma formation or neurologic deficit.

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LOW THORACIC EPIDURAL BLOOD PATCH FOR THE TREATMENT OF CHRONIC PDPH FROM MID-THORACIC DURAL TEAR M.B. Wunnava University of North Carolina, Chapel Hill, NC, USA 37 year-old female with a history of Addison´s disease and hypothyroidism with 6-week history of severe, intermittent, occipital headaches without tinnitus, photophobia, visual changes, diplopia, or other neurological symptoms. The headaches come and go, can last a few days at a time, and are at their worst first thing in the morning when standing and relieved when laying down. She had had numerous inpatient admissions for headache management. Prior to headache onset, she had a completely uneventful lumbar epidural in conjuction with labor and subsequent C-section. She began experiencing headache, nausea, and vomiting 24 to 48 hours afer C-section and was treated with opioids and antiemetics, and discharged on POD #4. She presented 10 days later with severe headache with unremarkable brain MRI/MRA. The headache resolved with opioids. The patient was discharged, but readmitted with headache again 4 days later. She presented with "the worst headache of her life" and received a lumbar puncture with a 22-gauge needle followed by a brain MRI. MRI showed changes consistent with intracranial hypotension, thought to be due to the antecedent lumbar puncture. Repeat brain MRI performed two days later showed diffuse dural thickening and enhancement, most consistent with intracranial hypotension. Anesthesiology had been consulted twice over the past 6 weeks, but did not recommend an epidural blood patch given no evidence of dural puncture on epidural placement as well as the atypical and intermittent presentation of her headache. Conservative measures were recommended again. A third repeat MRI of the brain was performed revealing increased signs of intracranial hypotension with sagging of the tentorium and midbrain with cerebellar tonsils sagging inferiorly through the foramen magnum. An MRI of the spine with contrast revealed a small extra-axial fluid collection on the dorsal and left lateral aspect of the thecal sac at the T6-T7 level, extending superiorly to the T4 level, suspicious for probable CSF leak. Neurosurgical consultation recommended against operative management of the CSF leak. Previous epidural and lumbar puncture were remote from the site of the suspected mid-thoracic CSF leak. It is possible that prior epidural placement, physiologic forces at play during labor, and subsequent lumbar puncture altered intraspinal forces, leading to a shear or tear of a pre- existing dural "weak spot" in the thoracic spine. The patient was stabilized and discharged from the hospital to the interventional pain clinic. Utilizing fluoroscopic guidance a 17-gauge tuohy needle was advanced to the T12-L1 interspace and access to the epidural space was gained using the loss of resistance technique with air. A catheter was advanced to the T9 vertebral body level, the patient´s blood obtained in a sterile fashion, and the blood was injected slowly through the catheter in 2-5 mLs aliquots at the T9, T10, T11, and T12 levels for a total volume of 18 mLs. The patient was discharged home with instructions to lie flat for 24 hours and to limit her activity for one week. At a 5-week follow up with her neurologist, she reports complete resolution of this headache and a return to work and infant caregiving.

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PULSED RADIOFREQUENCY ABLATION OF A TRANSPOSED ULNAR NERVE UNDER ULTRASOUND B. Valine, J. Modir Pain Medicine, UC San Diego, San Diego, CA, USA A 57 year-old male presented to the Pain Medicine Clinic complaining of chronic pain in 4th and 5th fingers and medial aspect of the forearm since a subcutaneous transposition of the ulnar nerve. He described pins and needles, hyperalgesia with burning sensation in the ulnar nerve distribution of the small finger and medial antebrachial cutaneous nerve. He had reproducible pain to percussion at the proximal portion of the flexor carpi ulnaris muscle. An EMG demonstrated residual focal slowing in the ulnar nerve at the elbow when flexed at 90° (34 m/s) and improved with the elbow extended (40 m/s) with evidence of chronic axonal loss but no indication of recent or ongoing axonal degeneration.

After treatment options were discussed, the patient elected to undergo a Pulse Radiofrequency Ablation (PRFA) of the left ulnar nerve under ultrasound guidance. The site of provocation was located and visualization of the transposed ulnar nerve proximal to the elbow was appreciated. An insulated 22-gauge 50mm RF cannula with a 10mm active tip was advanced under ultrasound until the nerve was stimulated with 50Hz sensory stimulation and achieved down to 0.5 Volts. The nerve was treated at 42 degrees C with 20ms pulse width and 2Hz for 1.5min. Perineural injection was visualized under ultrasound with 10mg of methylprednisolone and 3ml of 0.25% bupivicaine. The patient tolerated the procedure without adverse events and noted up to 60% pain relief at follow-up one month later.

A review of the literature demonstrates numerous case reports/series of PRFA of various peripheral nerves for chronic pain including: the obturator, femoral, sciatic, supraclavicular, intercostal, lateral femoral cutaneous , and pudendal nerves (1,2). PRFA appears safe and no adverse events were reported in these cases. A recent case report demonstrated pain relief after PRFA of the ulnar and median nerve following chemotherapy-induced peripheral neuropathy (3). As opposed to the aforementioned case, our patient suffered from a failed transposition of the ulnar nerve and an ultrasound was used to identify the nerve and safely guide the needle to the target. We feel that ultrasound conveys multiple significant advantages: 1) Sonography permits accurate assessment of nerve location despite distorted post surgical anatomic location 2) Ultrasound may convey diagnostic images such as neuromas which have been documented as possible targets for PRFA (4). 3) The needle tip can be advanced under real-time guidance to avoid vessels and nerves. 4) Under certain circumstances entrapment of nerves may be appreciated under dynamic imaging (5). 1) Benzon HT, et al: Essentials of Pain Medicine, Third edition 2011;434.

2) Malik K, et al: Pulsed radiofrequency. A critical review of its efficacy. Anaesth Intensive Care 2007;35:863-873.

3) Naveen Y, et al: Radio frequency ablation in drug resistant chemotherapy-induced peripheral neuropathy: A case report and review of literature. Ind J of Palliative Care 2010;16:48-51.

4) Restrepo-Garces CE, et al: Pulsed radiofrequency under ultrasound guidance for persistent stump-neuroma pain. Pain Pract 2011:11(1); 98-102.

5) Norbury, J.W. et al: Ultrasonographic Evaluation of Entrapment Neuropathies in the Upper Limb. Pract Neurology 2011;4: 38-44.

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SUBANESTHETIC KETAMINE INFUSION FOR POST-THORACOTOMY PAIN SYNDROME P.G. Nystrom Department of Veterans Affairs Medical Center, Dayton, OH, USA Introduction: Persistent post-thoracotomy pain (PTPS) can be a debilitating complication of surgery. Treatments with oral analgesics and invasive procedures have variable success rates. This case report describes an attempt at using a subanesthetic ketamine infusion for durable pain relief from PTPS.

Case description: A 49 y.o. male was evaluated for progressive left chest pain associated with dyspnea. He had a left diaphragmatic defect with partial extrusion of abdominal contents into the left hemithorax. A left thoracotomy was performed to repair the diaphragmatic defect with mesh. The patient did not consent to thoracic epidural anesthesia/analgesia, and pain was controlled postoperatively with opioid PCA and intercostal nerve blocks (ICNB) on POD#1 only. He continued to experience moderate to severe left lower chest pain over the next two months. The pain and oral analgesics interfered with his ability to function on the job because of cognitive dysfunction. He described the pain as constant, dull aching pain, rated 6/10, with intermittent sharp stabbing pain rated 8/10. Pain increased with activity and prolonged sitting but did not interfere with sleep in the supine position. Ten weeks postoperatively, ICNB were performed at T8-T11 with 0.5% bupivacaine and epinephrine 1:200,000. Complete pain relief lasted 16 hours after which the pain intensity returned to baseline. He returned for repeat ICNB with moderate sedation (midazolam, fentanyl, hydromorphone), performed by the same operator, technique, and local anesthetic solution combined with depomedrol 20 mg. Complete pain relief lasted 5 days. When the pain returned, the quality and intensity were as previously described. A 24 hour ketamine infusion was tried to achieve a more durable analgesia. Repeat ICNB at T8-T11 with moderate sedation (midazolam, fentanyl, hydromorphone, ketamine), was performed by the same operator, technique, and ICNB solution. Ketamine was continued at 2.5 mcg/kg/hr (16 mg/hr) for 24 hours. The patient experienced several episodes of mild nausea and anxiety treated with ondansetron and lorazepam. He was pain free at the time of discharge, but the pain returned to baseline intensity after 72 hours.

Discussion: PTPS affects many patients, and a small percentage of these will experience severe pain. Treatments consisting of neurolyis, spinal cord or peripheral nerve stimulators, vary in success rates. After neurolytic procedures, many patients have recurrence of pain which can be more severe than the original pain syndrome. Subanesthetic ketamine infusions of hours to days in duration have been successful in other chronic pain syndromes. The mechanism of action is related to NMDA receptor antagonism. This case describes an unsuccessful attempt to employ a subanesthetic ketamine infusion of relatively short duration to achieve a durable pain relief benefit. Before moving to more aggressive therapies, a ketamine infusion of longer duration and higher doses may be considered for PTPS. Presently, the patient uses less opioids, and he takes gabapentin only at night.

References:

Perttunen et al., Acta Anaesthesiol Scand 1999; 43:563-567

Gottschalk et al., Clin J Pain 2008; 24:708-716

Guastella et al., Pain 2011; 152:74-81

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TEMPORARY LOWER EXTREMITY PAINFUL SPASM, AN IMPORTANT PRECAUTIONARY SIGN IN CELIAC PLEXUS BLOCK, CASE REPORT F. Elahi, D. Callahan, W. Wu, C. Lassalle, B. Beutler, A.K. Bhandary Universty of Iowa, Coralville, Coralville, IA, USA The celiac plexus, also known as the solar plexus, is a complex network of nerves (a plexus) located in the abdomen, where the celiac trunk, superior mesenteric artery, and renal arteries branch from the abdominal aorta. It is behind the stomach and the omental bursa, and in front of the crura of the diaphragm, on the level of the first lumbar vertebra, L1.The celiac plexus block may be performed during surgery for postoperative pain relief also is useful for any condition that causes chronic severe upper abdominal visceral pain - e.g. chronic pancreatitis (local anesthetic blocks only). The celiac plexus block useful for upper abdominal organ cancer pain, and is frequently used for carcinoma of the pancreas - initial diagnostic local anesthetic block, followed by neurolytic block. The plexus block/neurolysis has specific complications explained in the literature like severe hypotension, Bleeding, Intravascular injection, Upper abdominal organ puncture with abscess/cyst formation, Paraplegia from injecting phenol into the arteries that supply the spinal cord, Sexual dysfunction, Intramuscular injection into the psoas muscle, Lumbar nerve root irritation.

In this case study, we discuss a 65 year old female with the diagnosis of metastatic duodenal adenocarcinoma, who underwent repetitive celiac plexus block, and neurolysis. She demonstrated temporary lower extremity spasmodic contracture throughout one of her procedure. However, painful lower extremity spasm relieved after cessation of procedure, the same clinical presentation repetitively observed with different needle trajectory. We will discuss importance of clinical finding, needle placement technique, anatomical variation due to prior pain procedures, and patient's outcome.

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COMBINED ULTRASOUND-GUIDED INTERSCALENE AND PARAVERTEBRAL CATHETERS FOR FOREQUARTER AMPUTATION V. Modest, J.L. Anderson-Dam, N. Sunder Department of Anesthesia, Critical Care, and Pain, Massachusetts General Hospital, Boston, MA, USA Objective:

We describe a medically challenging case reporting use of the first ultrasound-guided interscalene and high thoracic paravertebral catheters placed to provide analgesia to a broad anatomic region, including shoulder, axilla, back and chest wall.

Case report:

A 39 year-old male presented for palliative left forequarter amputation due to metastatic squamous cell carcinoma of the hand. He was on large doses of narcotics and had pain at rest and severe, searing pain on movement.

An interscalene catheter was placed, using an utrasound-guided in-plane technique, via a posterior/lateral approach. Shoulder pain rapidly resolved after injection of 15 cc of bupivacaine 0.5% with epinephrine. In a sitting position, a transverse ultrasound view of the paravertebral anatomy allowed continuous in-plane guidance of a 17 gauge Touhy needle into the T2-3 paravertebral space. Ten cc of bupivacaine 0.5% with epinephrine was injected and a catheter advanced after pleural depression observation. Dermatomes T2-5, on the involved side only, became insensate within 10 minutes.

After an uneventful general anesthetic and five-hour surgery, the patient awakened with no surgical pain. The catheters were effective and used through POD4.

Conclusions:

This is the first report of ultrasound guided double catheter placement (paravertebral and interscalene). Of note, continuous visualization of the needle tip and pleura during paravertebral catheter placement may prove to have a lower incidence of pneumothorax than blind techniques. This was important in this morbidly obese smoker about to undergo a large oncologic chest wall resection.

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CONTROLLED HYPOTENSION VIA COMBINED SPINAL/EPIDURAL TECHNIQUE IN A SICKLE CELL ANEMIA PATIENT UNDERGOING REVISION RIGHT TOTAL HIP ARTHROPLASTY N. Dhamija, N.N. Patel Anesthesiology, Ronald Reagan UCLA Medical Center, Los Angeles, CA, USA Introduction: We present a case of successful anesthetic management and good surgical outcome in a patient with sickle cell anemia, using controlled hypotension via combined spinal/epidural (CSE) technique for a high-risk, revision right total hip arthroplasty.

Case: A 40-year-old male with sickle cell anemia, with baseline hemoglobin (Hb) 6.0 g/dL and a history of bilateral hip hemiarthroplasties, sustained a right periprosthetic proximal femur fracture after a fall, warranting surgical repair. Because of multiple prior transfusions, he developed numerous antibodies, and only 7 units of type-specific blood were available in the country, of which 4 units transferred to our institution.

The patient´s preoperative evaluation was otherwise unremarkable (baseline BP 132/68, HR 74). Due to sickle cell crisis, he required aggressive intravenous (IV) hydration, and high- doses of IV hydromorphone via patient-controlled analgesia (PCA), IV methadone, and fentanyl patches. He was also transfused 1 unit of packed red blood cells (pRBC) with a resultant Hb of 6.7 g/dL. Preoperatively, he received 1 L of crystalloid therapy. A left radial arterial line and left internal jugular central venous catheter were placed under local anesthesia. In the lateral decubitus position, epidural space was accessed at the L1/2 level. A spinal needle was introduced into the subarachnoid space and 3 mL of bupivacaine 0.5% was injected. Subsequently, an epidural catheter was placed and secured. An intravascular epinephrine infusion at 3 mcg/min was then started. After confirmation of bilateral sensory block below the T4 level, incision was made. Through the epidural catheter, he received approximately 10-15 mL of lidocaine 2% every 45 minutes. Intraoperatively, the patient remained awake, but received supplemental analgesia with IV methadone, fentanyl, and ketamine. Normal mentation, spontaneous ventilation, sinus rhythm, pulse oximetry, arterial oxygen and carbon dioxide tensions, temperature, urine output as well as MAP ≥ 50 were maintained. His BP ranges were 80-111/30-64 (MAP 47.3-79.3) and HR ranges were 59-90 (Figure 1). He received of a total of 3.5 L crystalloids, 1 unit pRBC (after Hb dropped to 5.0 g/dL), and 100 mL of cell-saver blood. His estimated blood loss was 1000 mL and urine output was 400 mL. Postoperatively, he was transferred to the ICU in stable condition. His immediate postoperative Hb was 5.4 g/dL and 6.0 g/dL on POD 1, requiring no further transfusions. His pain was well-controlled on IV and epidural PCAs, with no recurrence of sickle cell crisis. The patient was transitioned to oral analgesics and discharged home on POD 8.

Discussion: Although anemia is a relative contraindication in controlled hypotensive anesthesia, minimal availability of type-specific blood rendered our patient´s sickle cell anemia the primary impetus for use of this technique. Using CSE-mediated hypotension, we limited blood loss in a complex revision, reduced transfusion requirements, improved intraoperative field exposure, and shortened the duration of the surgery, without adverse cardiac or cerebral effects. Therefore, controlled hypotension can be utilized safely and effectively in anemic patients undergoing high-risk surgeries when blood products are scarce.

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PERSISTENT EPIDURAL FLUID AT THE CERVICAL SPINE LEVEL N. Vanga, M.N. Rupasinghe Anesthesiology, UTHSC, Houston, TX, Anesthesiology, UTHSC, Houston, TN, USA Persistent Epidural Fluid at the Cervical Spine Level

Post-dural puncture headache (PDPH) was first described by August Bier in 1898 and classically presents as a postural headache following therapeutic or diagnostic interventions of the epidural or spinal space. The incidence of PDPH is estimated to be between 30-50% following diagnostic or therapeutic lumbar puncture, 0-5% following spinal anesthesia and up to 81% following accidental dural puncture during epidural insertion in the pregnant woman.

Although PDPH usually resolves spontaneously, it is unpleasant, it may interfere with a new mothers ability to care for her newborn and it may extend the length of hospital stay. More rarely PDPH may be associated with serious complications such as subdural hematoma, seizures and sagittal sinus thrombosis.

The symptoms of PDPH are a postural headache, usually fronto-occipital and of a throbbing or dull aching nature and often accompanied by dizziness, nausea and vomiting, visual disturbances, interscapular pain, nuchal rigidity, photophobia and auditory symptoms.

There are two possible mechanisms of headache. First, the lowering of CSF pressure causes traction on the intracranial structures in upright position. These structures are pain sensitive, leading to the characteristic headache. Secondly, the loss of CSF produces a compensatory venodilatation as per the Monro-Kellie doctrine. The consequence of a decrease in CSF volume is a compensatory increase in blood volume. The venodilatation is then responsible for headache.

It is well known that a PDPH can occur in the absence of a visualized dural puncture and we recently encountered a rather peculiar presentation in an obstetric patient.

Case Report

A healthy 28 year old Caucasian female, gravida 1 para 0 was admitted to the labor and delivery floor for induction of labor. The patient requested an epidural for pain management. The epidural space was found after three attempts. The patient labored for nearly 7 hours with a good working epidural and subsequently delivered uneventfully.

Approximately twelve hours later, the patient began to complain of a headache. It was described as unilateral, 6/10 intensity, and mildly increased in the upright position. The patient was assessed and initial course of action was observation with bed rest and hydration. Approximately 6 hours later the anesthesiologist was called as the headache had still not resolved and the patient reported an acute worsening when she attempted ambulation to shower. The patient was educated regarding the possibility of a post-dural puncture and treatment options. Due to the slightly unusual presentation of symptoms and elevated patient concern an MRI of the brain and neck was obtained.

IMPRESSION:

Epidural collection throughout the cervical spine, as high as C2-3. Epidural fluid or hemorrhage is possible. Given the homogeneity of the collection blood products may be less likely.

After the results of MRI and further discussion with the patient an epidural blood patch was performed. The procedure was performed successfully and uneventfully and the patient expressed an improvement in symptoms and was later discharged home that evening.

Discussion

It was interesting to note the extent of spread of CSF within the epidural space as per the MRI image.

PDPH is a common complication resulting from intentional or accidental dural punctures. Patients who experience a PDPH should not be taken lightly. Data obtained from the ASAs closed claims analysis project showed that this is the third most common reason for litigation in obstetric anesthesia. Anyone being treated for a PDPH should receive reassurance as well as a full and frank discussion of diagnostic and treatment options.

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HOW VIGILANT POSTOPERATIVE MONITORING AFTER SUPRACLAVICULAR BLOCK HELPED THE DIAGNOSIS AND TIMELY MANAGEMENT OF ISCHEMIC UPPER LIMB: A CASE REPORT G. Sudhakaran Nair, K. Maheshwari, L. Mounir Soliman, W. Ali Sakr Esa Anesthesia, Cleveland Clinic Foundation, Cleveland, OH, USA Case report: A 58 year old female who came for revision of her right total shoulder was given ultrasound guided supraclavicular nerve block with catheter for postoperative pain management. Following the nerve block, surgery was done under general anesthesia. The surgeon reported a difficult yet uncomplicated procedure. Postoperatively, infusion of 0.2% Ropivacaine as PCA was started through the catheter and the limb was monitored according to the institution guidelines. Nine hours (0400Hrs) after the end of surgery the patient complained of pain along the medial side of forearm away from the surgical site. On examination the arm was warm, slightly dusky, capillary refill was brisk and peripheral pulses palpable. She was given a top up of 15cc of 0.5% Ropivacaine which relieved pain. Neurovascular checks were done hourly. Examination at 0900 hours showed that the hand was cyanosed and pulses were weak. The patient reported increasing pain in the hand. Aortic angiography showed a 3cm segment of occlusion of the axillary artery adjacent to the shoulder joint. Immediate exploration confirmed a partial occlusion which was repaired by an arterial bypass using saphenous venous graft. Pulses in the limb returned. Patient was discharged home on the fourth postoperative day with full neurological and functional recovery.

Discussion: Continuous peripheral nerve blocks are routinely performed at our institution to enable early physiotherapy and faster discharge for orthopedic patients. Our patient had iatrogenic injury to the axillary artery which was not identified intraoperatively. The patient developed signs of limb ischemia which was partly masked by the nerve block. However, early intervention and limb salvage surgery was possible due to the practice of continuous neurovascular monitoring. Currently there are no guidelines or recommendations for postoperative monitoring after nerve blocks. In our institution, it is routine to monitor the capillary refill, sensation and movement of the surgical limb every 15 minutes for the first hour and then every 30 minutes till the return of sensation. Pulses are checked every 2 hours in the PACU and continued to every 4 hours.

Iatrogenic injuries to vessels and or nerves are not uncommon during orthopedic surgeries. They manifest first during the immediate postoperative period. Previous studies(1) have confirmed the need for early limb saving surgeries in patients with vascular injuries. Regional anesthesia can mask and delay the onset of symptoms of ischemia. This can convert regional anesthesia from a boon in pain control to a harbinger of complications. Postoperative monitoring and ability to differentiate between the effects of local anesthetics and the body´s response to ischemia is important to avoid complications related to vascular injuries in the postoperative setting. Pain in an area unrelated to the surgical site needs to be evaluated and constantly followed up.

Conclusion: This case report aims to improve awareness among pain physicians about the need for vigilant monitoring after peripheral nerve blocks.

1.Vascular Injuries Associated with Elective Orthopedic Procedures. Ann Vasc Surg 2003;17:641 -644

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CAUDA EQUINA SYNDROME FOLLOWING ROPIVACAINE EPIDURAL ANESTHESIA J. Panchamia, E. Nada, M. Ritchey, L. Mounir-Soliman, W. Ali Sakr Esa Anesthesiology, Cleveland, Cleveland, Cleveland, Cleveland, OH, USA Case Report

A 70-year-old female patient was scheduled for a left revision total knee arthroplasty. An epidural catheter was placed at lumbar 2-3 interspace uneventfully. Both the catheter aspirate and test dose were negative for intrathecal placement. A total of 19 cc of 1% ropivacaine was administered in divided doses with negative aspiration of CSF or blood before each given dose. A final sensory block at the level of T7 was obtained. Surgery took place in the supine position, lasting four hours, with minimal blood loss, and the patient remained hemodynamically stable. A patient controlled epidural anesthesia infusion with 0.1% bupivacaine and fentanyl 2mcg/mL was started post-operatively. On postoperative day one, patient complained of motor and sensory weakness of the lower extremities, which did not resolve on holding the epidural infusion. On postoperative day three, the bladder catheter was reinserted due to urinary retention. On that day, magnetic resonance imaging (MRI) without contrast revealed clumping of the lumbosacral nerve roots, without nerve root compression. Additional history, which the patient did not disclose during her pre-operative visits and on her day of surgery interview, revealed that the patient had chronic L3-L4 radiculopathies, as well as significant temporary motor weakness of lower extremities following bilateral femoral nerve blocks for total knee replacements 3 years prior.

On postoperative day eight, the patient developed bowel and bladder incontinence, decreased rectal tone, and perianal hypoesthesia. That day, a lumbar MRI with contrast showed extensive enhancement of the cauda equina nerve roots. Lumbar puncture demonstrated an aseptic inflammatory response. Electromyogram studies showed severe bilateral subacute axonal loss polyradiculopathy of the lower extremities. A diagnosis of cauda equina syndrome (CES) due to chemical arachnoiditis was made. Treatment was with IV corticosteroids. At her one month follow up visit, the patient had some improvement in motor and sensory function of the lower extremities, but bowel and bladder dysfunction remained. The patient failed to return for further follow up.

Discussion

CES is a known complication of neuraxial anesthesia that results from an insult to the sacral nerve roots in the neural canal. Ropivacaine epidural anesthesia is an exceptionally rare cause of CES. This case highlights the potential for epidural anesthesia to induce CES despite no evidence of structural complications or direct needle trauma as a cause for the neurological developments. We will discuss mechanisms in general and arachnoiditis in particular, which may contribute to the development of this crippling condition following epidural anesthesia.

In conclusion, CES can occur following ropivacaine epidural anesthesia. Patients with pre- existing neuropathy may be at increased risk of developing neurological complications as a result of regional anesthesia. In such situations, anesthesiologists should weigh the risks and benefits of neuraxial anesthesia against the alternatives. When neuraxial anesthesia is administered, it may be reasonable to use lower concentrations and lower doses of local anesthetics.

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REGIONAL ANESTHESIA FOR PECTORALIS MAJOR TEAR SURGERY L. Curia, S. Lucas, S. Pyne, I. Voloshin Anesthesiology, URMC, Orthopedics, Rochester, Rochester, NY, USA The pectoralis major muscle is a powerful adductor, internal rotator and flexor of the shoulder. Rupture of the pectoralis major is a very uncommon injury seen in young males during sports practice.

Although most cases are undoubtedly partial, most reported injuries have been complete ruptures, predominantly affecting the distal musculotendinous junction or insertion of the tendon.

Early surgical repair of distal pectoralis major tendon ruptures and an accelerated rehabilitation protocol provide reliable restoration of shoulder function and strength. These surgeries are usually carried out in outpatient facilities with a combination of General and Regional Anesthesia. Regional Anesthesia has not been widely described for them since it is a difficult location to perform a block with vast coverage.

We present a case of pectoralis major rupture that we encountered last fall at the University of Rochester.

Case report:

53 year old male with no past medical history presented for surgical repair of a left pectoralis major tear. After obtaining informed consent, patient was given 2 mg of midazolam and 100mcg of fentanyl. Patient was placed in the sitting position with exposure of the upper thorax. The left side was prepped and an ultrasound probe used to identify paravertebral spaces, focusing on T2 and T4. Using an in-plane technique and a 24G 5cm Stimuplex needle we injected 7mL of 0.5%Bupivicaine with Epinephrine 1:200,000 at each level.

The patient was placed in the recumbent position, and 6mL of the same local anesthetic mixture was injected as a subdermal skin wheal at the base of the patient's neck to cover cervical plexus contributions via the supraclavicular nerves. A left infraclavicular approach to the pectoral nerves was performed at the border of the Pectoralis Major and Pectoralis Minor using a 24g 5cm needle and 10 ml of the same LA mixture

Intraoperatively, patient anesthesia requirements were significantly decreased to about 0.5 MAC of Desflurane and minimal narcotics.

In the postoperative period, patient complained of 4/10 pain in the T3 distribution which prompted us to perform a T3 paravertebral block. 15ml of Bupivicaine 0.5% with epinephrine were used at this time. No complications were noted and patient was discharged home with 0/10 pain.

On postoperative day 2 patient was contacted and he stated his recovery had been fantastic with over 24 hours being pain free and a pain score of 2/10 at 48 hours.

Discussion:

Rupture of the pectoralis major muscle can occur from infancy to old age, but sports-related injuries tend to occur from the 2nd to the 4th decades. It is a relatively rare injury that prompts early surgical repair for best outcomes. Surgeries are usually performed in the ambulatory setting under general anesthesia. We described a case of combined general and regional anesthesia.

The paravertebral block is well described for adjuvant analgesia for breast surgery. The technique consists of injecting LA adjacent to the thoracic vertebra close to where the spinal nerves emerge from the intervertebral foramina, resulting in both somatic and sympathetic block in contiguous dermatomes. The typical technique is to have the patient sitting up and using a 22G Tuohy needle with LOR technique. Our idea is not to describe such technique but actually an innovative way of performing the block under ultrasound. Ultrasound guidance offers a direct identification of structures with visualization of needle positioning and LA spread. There is little literature describing techniques for promoting good analgesia for pectoral surgery while addressing both the overlying cutaneous innervation and the motor innervation of the pectoralis muscle. Approaching the lateral and medial pectoral nerves at this location may assist in minimizing patient discomfort from involuntary muscle contraction while preserving arm function.

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ANTERIOR SCIATIC NERVE CATHETER A CASE SERIES M. Guirguis, S. Zaky, S. Kolli, A. Abd-Elsayed, L. Mounir Soliman Cleveland Clinic, Cleveland, Cincinnati, Cincinnati, Cincinnati, OH, USA Introduction: Sciatic nerve block is classically performed through posterior or lateral approach. With the increased use of U/S the ant. approach to sciatic n. has gained popularity. An ant. approach should be considered in patients after trauma and severe postoperative pain where patient positioning can be challenging. Here we describe 3 cases where an ant. approach was used to place indwelling sciatic nerve catheter under U/S guidance.

Case1:A 46 y old female with CRPS 1 involving both lower limbs was scheduled for elective right ankle surgery. Managing the patient's perioperative pain was challenging as patient had very limited movement of her limbs due to excruciating pain. Positioning this patient for sciatic n catheter at the popliteal fossa was nearly impossible and hence we inserted a sciatic catheter using ant. approach under U/S guidance.

Case2:A 53 y old woman with severe osteoarthritis of the right knee, who was on pain medications at home. The patient received an indwelling FNC prior to total knee Arthroplasty, but had significant pain at the back of the knee in PACU. She received a sciatic n catheter placed via ant. approach under U/S guidance.

Case3:A 66 y old woman who underwent a right below knee amputation. She was in severe pain in PACU and was known to be intolerant to most opiates. Hence both femoral and sciatic n catheters were placed via ant. approach. The patient had significant pain relief and comfortable postoperative period.

Method: Patients were positioned supine with some external rotation of the corresponding lower extremity. Skin was prepped using standard technique and U/S was used to scan for the sciatic nerve using ant. approach. A curvilinear probe was used to allow for deep tissue scanning. The Sciatic nerve was identified deep to adductor muscle medial to the femur and about 10 cm distal to the inguinal crease. A 6" tuohy needle was used to approach the nerve with stimulation elicited at 1mA or less in each case. 20 ml of 0.5% ropivacaine was injected and the catheter was inserted 5 cm past the needle tip. Infusion was started in each case using ropivacaine 0.1% at 8 cc basal rate.

Discussion: The recent use of U/S has made the ant. approach to sciatic nerve more feasible and safer. The nerve can be visualized using real time ultrasonography and catheter can be placed safely avoiding damage to major blood vessels and the nerve itself. The anatomical land mark techniques can be difficult for ant. approach and cannot always be relied on due to inconsistency and increasingly obese population. The presence of large blood vessels in the needle path and increasing use of anticoagulants emphasize the use of U/S guidance for ant. approach to sciatic n.

Conclusion: The anterior approach for the placement of sciatic nerve catheter is safe when facilitated with u/s guidance. This technique is very useful in patients who cannot be positioned for the conventional post. approach to the sciatic nerve. Recent study has shown that the ant. approach to sciatic nerve block can be performed as easily and successfully as the post. approach using the U/S guidance. Inserting sciatic n catheter using the ant. approach under ultrasound guidance is relatively new and could potentially save time & provide more safety.

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CASE STUDY: SPINAL CORD STIMULATION TO ACHIEVE PAIN RELIEF IN A PATIENT WITH CRPS TYPE I OF THE TRUNK S. Sastry, K.H. Berger Lake Mary Pain Relief, Lake Mary, FL, USA Case study: Spinal Cord Stimulation to Achieve Pain Relief in a Patient with CRPS Type I of the Trunk

Background and aims: Patients afflicted with Complex Regional Pain Syndrome Type I (Reflex Sympathetic Dystrophy) often suffer from persistent, unrelenting chronic pain. Most of these patients are affected either in the upper and/or lower extremities. Spinal cord stimulation has been shown to be effective in treating this type of pain presentation. Unfortunately, cases of CRPS Type I in which the pain is in the truncal region have not been as well studied. The challenge of SCS is to adequately provide pain relief coverage without producing noxious stimulation in other regions, i.e. the ribs. Little is published in such cases.

Methods: Case study completed by retrospective review of the chart and via telephone interviews with a patient suffering from CRPS of the left trunk region of the back. Conservative therapies failed to provide the patient with significant pain relief. Two spinal cord stimulator leads were placed in a 47 year old female diagnosed five years previously with truncal CRPS. Trial octrode cylindrical leads were placed at T5-6 to cover the left flank and C 2-3 to cover neck pain from cervical post laminectomy syndrome. The patient achieved paresthesias and stimulation overlapped in the left flank region from the thoracic lead. The cervical lead did not result in any significant paresthesia, and therefore was not utilized. Following the successful trial, the patient was implanted with an S-type paddle lead and a conventional rechargeable generator.

Results: During the trial period, the patient reported 90% pain relief in the left flank. One year post-op, the patient reported 80% pain relief. Three years post-op, the patient still reports 80% overall reduction in pain.

Conclusion: Patients with atypical CRPS Type I (truncal pain) may benefit from a trial of spinal cord stimulation. Further studies are warranted.

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THE CLINICAL CONUNDRUMS OF RETAINED EPIDURAL CATHETERS: A CASE REPORT M. Piske, K. Schroeder Anesthesiology, University of Wisconsin Hospital and Clinics, Madison, WI, USA Introduction:

Breakage of an epidural catheter is fortunately a rare occurrence, with only 30 case reports in 15 studies in the literature since 1957. Despite widely acknowledged methods for careful removal and troubleshooting difficult situations, it is a potential complication that can still occur, and the proper management of this situation is still somewhat controversial. Because removal so often is easy and uncomplicated, the potential exists for even seasoned Anesthesiologists to underestimate potentially challenging cases and unwittingly ignore the basic tenets of safe removal. Furthermore, the decisions made in management of the complication can have significant implications for an affected patient's length and cost of hospital stay.

Case Presentation:

We present a recent case at our institution of a 77 year-old obese female with osteoarthritis who presented for total knee arthroplasty. She underwent uneventful placement of a lumbar combined spinal epidural and femoral nerve catheter pre-operatively and the surgery itself was also unremarkable. As has become the routine at our institution, the epidural catheter was to be removed after surgery prior to the patient being admitted to the general care floor. This was done by the Staff Anesthesiologist responsible to the case. The removal proved difficult however, as the patient was reluctant to assume the lateral decubitus position due to pain, and no other methods were implemented to allow for easier removal. This resulted in excessive force being applied to the epidural catheter. The catheter ultimately sheared and broke, which left us to consider the appropriate management. Neurology was notified and it was determined that imaging should be obtained to precisely determine the location of the catheter fragment, as advocated in the available literature. Because of it's swift availability, plain films of the lumbar sine were obtained in the recovery room, which predictably revealed little diagnostically due to the patient's body habitus. CT scan was then performed following discharge from the recovery room. The scan very clearly depicted the tip of the catheter in the epidural space at the level of L2-L3, extending from the posterior epidural space and coiling inferiorly, exiting in the interspinous ligament at that level. CT imaging also revealed very narrow intervertebral spaces and multiple bone spurs. Because the patient had no neurological symptoms, no further intervention was undertaken and the patient thus far has had an uneventful recovery from her surgery. The patient received education regarding the situation and told about potential complications and “red flags” to watch for.

Discussion:

This case illustrates many important discussion points relevant to everyday practice and to resident education. First, the essential knowledge of proper technique for epidural removal, which in this case was not followed even by a very experienced Anesthesiologist, and who also failed to consult colleagues specializing in regional anesthesia that were readily available to assist when removal became difficult. Second is consideration of the most appropriate imaging. CT imaging currently is the most widely advocated modality, though other potentially less costly methods such as flouroflouroscopy and ultrasound may also suffice. Third is potential surgical intervention. There is currently no evidence to support routine surgical removal of an epidural catheter fragment without concurrent neurological symptoms, however this continues to be the most controversial issue we face in this situation, particularly if the catheter is located intrathecally. For this case, it remains to be seen what effect, if any, the retained catheter will have on this patient's future medical care, and discussion points with this case as in many of these cases involve questions not easily answered with evidence-based guidelines.

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ULTRASOUND-GUIDED BILATERAL SUPRACLAVICULAR NERVE BLOCK FOR THE TREATMENT OF EXCRUCIATING PAIN SECONDARY TO REYNAUD´S PHENOMENON A. Tharian, A. Reid, N.N. Knezevic Anesthesiology, Advocate Illinois Masonic Medical Center, Chicago, IL, USA Introduction: Ultrasound guided supraclavicular brachial plexus block provides effective anesthesia to the upper extremity and has a low rate of complications.1

Case description: A 63-years-old man presented to the emergency department with cold fingers and bilateral hand pain, discoloration, and swelling. The patient stated that the previous day, he cleaned a roof for 10 hours on an outside temperature of low 40s Fahrenheit. That evening he developed mild hand pain that by the next morning was 9 out of 10 on the numeric rating scale, and it was accompanied by blistering, bruising and swelling. The patient had no significant PMH, PSH, allergies. On physical exam, the patient´s hands were cold to touch, and he had swelling of the distal phalangeal region of his right second, third and fourth digits and left second and third digits. Nail beds of fingers were cyanotic and dorsal aspects of fingers and hands were ecchymotic with multiple blisters (Figure 1). The patient was initially treated with Silvadene cream (contains 10 mg of micronized silver sulfadiazine), and the anesthesiology team was consulted for management of excruciating pain. We decided to proceed with supraclavicular nerve block for pain relief. The patient was brought to the PACU for continuous monitoring, and his left supraclavicular region was sterilely prepared. Under ultrasonographic guidance, a 22 gauge, 5 cm PAJUNK needle was used for a left supraclavicular block. Fifteen milliliters of 0.2 % ropivacaine was incrementally, with intermittent aspiration, injected around the brachial plexus at the level of the supraclavicular region (Figure 2). It was immediately noted after the block that left hand was warm to the touch with visible erythema. The patient was then continuously monitored for 1.5 hours for signs of toxicity and respiratory distress. He tolerated the procedure well, and vital signs remained stable. After that, we decided to perform a right supraclavicular block under ultrasound guidance utilizing the same drug dosage and technique, with similar outcome. The patient was monitored for another 1.5 hours for signs of toxicity and respiratory distress. The patient tolerated the second procedure well without complications. The patient reported less pain in his fingers after blocks, and on the post procedure day 3, he was discharged home with significant improvement of his hand pain and skin discoloration. Discussion: The sympathetic system has an important role in the pathophysiology of Reynaud´s disease, and treatment modalities aimed at blocking sympathetic innervation have been used in management of the symptoms of Reynaud´s phenomenon.2 The exact etiology of our patient's clinical findings is unclear, although most likely he had a Reynaud´s phenomenon secondary to cold weather or to exposure to chemicals used for cleaning the roof. However, we believed that the acute onset of excruciating pain and the risk of onset of gangrene from severe vasospasm necessitated a quick and reliable technique to achieve bilateral sympathetic blockade of the upper extremities. We decided to perform bilateral supraclavicular block instead of stellate ganglion block to minimize the possibility of profound bradycardia and heart block that can arise from blockade of the cardiac accelerator fibers that can result from bilateral stellate ganglion blockade. The supraclavicular brachial plexus block was very effective in pain relief as well as in increasing blood flow in patient's hands.

References:

1. Perlas A, et al. RAPM 2009;34:171-6. 2. Kulkarni KR, et al. Indian journal of anaesthesia;54:546-51.

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PERIOPERATIVE PAIN MANAGEMENT IN A PATIENT WITH SYSTEMIC MASTOCYTOSIS FOR HIP RESURFACING PROCEDURE D. McCutcheon, J. Crews Anesthesiology, Wake Forest University School of Medicine, Winston Salem, NC, USA The objective of this case report is to raise awareness of options for acute pain management and perioperative optimization of patients with systemic mastocytosis. A 58 year old male presented to the operating room for hip resurfacing. His history was significant for systemic mastocytosis, hypertension, transient ischemic attack, and syncope. Systemic mastocytosis is an extremely rare condition in which there is an over proliferation of mast cells which can be triggered to release massive amounts of histamine. Physical stimulus such as heat, cold, pressure, endoscopies, emotional stress, and numerous drugs have been associated with anaphylactic reactions. His last anaphylactic reaction had occurred one year prior to presentation following ingestion of ibuprofen. The patient was seen preoperatively in the preanesthesia clinic and then was referred to an allergy and immunology specialist for further workup and planning. The patient was given a preoperative regimen that included steroids, diphenhydramine, ranitidine, and a leukotriene receptor antagonist by his allergist. Regional anesthesia was favored in an attempt to minimize or avoid narcotics and nonsteroidal anti- inflammatory agents as these are known triggers for anaphylaxis in this patient population. Environmental conditions were optimized by maintaining room temperature at 68-70 degrees F, providing a quiet and relaxed atmosphere. A lumbar plexus block was placed for postoperative analgesia and a subarachnoid block for surgical anesthesia. Preblock medications were given including hydrocortisone, diphenhydramine, ranitidine, and acetaminophen. The patient was sedated with intravenous midazolam and fentanyl, both known to be relatively safe in these patients. Local anesthetic for both the lumbar plexus and subarachnoid block was ropivicaine with 1:200,000 epinephrine. The procedures were well tolerated. Intraoperatively the patient was sedated with intravenous propofol. The patient was comfortable in the postoperative recovery room and he was given a fentanyl pca and scheduled acetaminophen for postoperative pain. The patient used his pca fentanyl very infrequently favoring acetaminophen however tolerated fentanyl without incidence. Therefore, prior to discharge the patient was given a fentanyl lollipop. He tolerated this without incidence and was given this medicine for use at home. The patient was discharged after several days once he was cleared by physical and occupational therapy. On follow up the patient reporting using the fentanyl lollipop only once and reported little postoperative pain. There is very little data published on the perioperative management of patient´s with systemic mastocytosis. Due to the extremely low incidence of the disease, the data consists mostly of case studies. In this case, we avoided medications that had a strong history of triggering anaphylatic reactions. We believe that we used a relatively safe protocol for the procedures and for postoperative pain management that allowed for this patient to have a successful hip resurfacing and uneventful recovery and believe that this management plan can serve as a guideline for acute pain management for this patient population.

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DELAYED POSTOPERATIVE RESPIRATORY FAILURE DUE TO INTRATHECAL OPIATE HYPERSENSITIVITY D. Beausang, G. Hsu Anesthesiology, Thomas Jefferson Univ. Hospital, Philadelphia, PA, USA This is a case of delayed postoperative respiratory depression following intrathecal opiate analgesia (ITOA) for ORIF of a femur fracture. This case illustrates the pharmacologic properties of intrathecal opioids and the appropriate approach and treatment to postoperative respiratory depression due to ITOA.

The patient is a 66-year old female, encountered in the PACU following left femur ORIF. She suffered a pathologic femur fracture secondary to a bone metastasis from non-small cell lung carcinoma. Other than her primary neoplasm she denied pulmonary pathology and was a non-smoker. She is 5'10'' with a BMI of 34.6 and a Class IV airway. The intraoperative period, under a spinal anesthetic of 17.5mg of 0.5% bupivicaine and 0.2 mg of morphine, was uneventful. She remained hemodynamically stable, breathing spontaneously while maintaining greater than a 97% O2 saturation. She had an uneventful, two-hour stay in the PACU. Shortly after arriving on the floor, the patient stated, "I don't feel like I have any air". Her respiratory rate was 16 with a sat of 85% on 3L NC. She was transferred back to the PACU and the anesthesia team was called to the bedside to evaluate the patient's increased somnolence.

On arrival, she had a respiratory rate of 7 with a sat of 90% on NRB. She was arousable and had no complaints of chest pain. Her ABG was as follows: pH 7.10, pCO2 117, pO2 61, HCO3 35, O2 Sat 83% on NRB. The patient was hyperventilated and ordered bolus administration of 40 mcg of naloxone. Her mental status improved briefly and the treatment was repeated with the same result. A naloxone infusion was titrated to effect with full resolution and she was transferred to the intensive care unit for monitoring.

The patient left the PACU with stable vitals >4.5 hours after the initial spinal was placed, only to return with respiratory failure. Her response to naloxone and mask ventilation confirms her diagnosis of opiate induced respiratory depression. When given intrathecally, morphine diffuses readily with the CSF and migrates cephalad. A study examining response to intrathecal morphine in healthy volunteers showed desaturations < 85% in 0 of 5, 2 of 5 and 4 of 5 subjects receiving 0.2, 0.4 and 0.6mg, respectively. This study had very few participants and our patient would certainly not pass as a healthy volunteer, but one might infer, that based on this data, she showed an increased sensitivity to intrathecal morphine.

After ruling out other potential cardiopulmonary sources of respiratory depression and settling on ITOA as the source, we approached her treatment in two steps. One was the pharmacologically reversal and the other was to correct her hypercaria. Naloxone without aggressive bag mask ventilation would not have improved her respiratory and cognitive status. Our avoidance of intubation is part of what makes this case unique. We suspect that circumstances much like ours result in intubations regularly, exposing the patient to unnecessary risk, of intubation and mechanical ventilation, lengthening hospital stays and increasing costs.

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EPIDURAL BLOOD PATCH OF POST-DURAL PUNCTURE HEADACHE IN THE HIV POSITIVE PATIENT C. Cassara, M. Donnelly, K. Schroeder Anesthesiology, University of Wisconsin, Madison, WI, USA Introduction:

The recognition of central nervous system (CNS) involvement with the HIV infection has increased the need for lumbar puncture and CSF sampling for diagnostic studies. A post-dural puncture headache (PDPH) occurs in 10-30% of patients following lumbar puncture with a 22 gauge needle. Epidural blood patch (EBP) is generally accepted as the definitive treatment for patients with a PDPH. HIV itself has not been shown to increase the risk of PDPH following dural puncture. Despite reports of EBP safety in HIV positive patients, there continue to be questions concerning introduction or acceleration of the course of virus spread into the CNS among healthcare professionals.

Case description:

A 32 year old man with HIV/AIDS was referred to the acute pain service for an EBP following lumbar puncture and subsequent persistent positional headache. The patient's most recent CD4 count was 14 with 355,000 viral copies on HAART therapy. Following description of the procedure, as well as risks (including theoretical risk of CNS seeding) and benefits of EBP, the patient elected to proceed with conservative management consisting of fluid hydration, caffeine and tramadol. The patient reported significant improvement in the severity of the headache on follow-up and no EBP was required.

Discussion:

CNS involvement in patients with HIV is generally caused by secondary opportunistic infections or the virus itself. CNS manifestations of HIV include dementia, aseptic meningitis and chronic headaches. It is generally accepted that the virus crosses the blood brain barrier early in the disease. An EBP may theoretically contribute to passage of the virus into the subarachnoid space; however, there are no long term studies that demonstrate a worsening of the CNS disease following EBP.

A 1991 letter to the editor in Anesthesiology suggested that autologous EBPs are best avoided in the HIV positive patient. A 1992 case series (Anesthesiology) of 6 patients was unable to identify any neurocognitive performance, neurologic or infectious sequelae following EBP in HIV positive patients.

While EBPs are certainly not without risk (Back pain, meningitis, acute arachnoiditis, severe radicular back pain and cauda equina syndrome are possible adverse outcomes), conservative therapy has little evidence to support its routine use. In this case, the patient elected to proceed with conservative therapy including increased fluid and caffeine intake after having a discussion about the theoretical risk of CNS seeding. This patient was fortunate that his headache resolved without requiring intervention. Many PDPHs will resolve with the first 1-2 weeks if not treated which may explain the relief that was seen with this patient. Recent evidence has emerged which suggests that tramadol may also be effective. Further research with larger numbers of patients is needed in patients with HIV undergoing EBP to further define and allow practitioners to more accurately describe the risks associated with this procedure.

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IMPACT OF LOCAL ANESTHETIC CHOICE ON PERIOPERATIVE OUTCOMES IN BREAST SURGERY WHEN A PARAVERTEBRAL BLOCK IS USED AS THE PRIMARY ANESTHETIC M. Donnelly, B. Anderson, M. Ford, J. Blake, T. Broderick, K.M. Schroeder Anesthesia, University of Wisconsin, Anesthesia, Madison, Madison, WI, USA Introduction: Anesthetic technique can have a profound impact on the perioperative course of patients undergoing breast surgery. Previous research has demonstrated that a paravertebral block (PVB) for breast surgery can decrease postoperative pain with movement and at rest, and reduce opioid consumption and nausea. Previous research has also demonstrated that equal concentrations of ropivacaine and bupivacaine may perform similarly when used for peripheral nerve blockade. We hypothesized that equal concentrations of ropivacaine and bupivacaine would perform similarly in patients undergoing breast surgery with an ultrasound (US) guided PVB as the primary anesthetic.

Methods: We performed a retrospective chart review of 300 consecutive patients presenting for breast surgery. Patients were then divided by surgical type resulting in 126 patients presenting for lumpectomy surgery with axillary node dissection under US guided PVB using either 0.5% ropivacaine or 0.5% bupivacaine. Of these patients, 98 patients received 0.5% bupivacaine and 28 patients received 0.5% ropivacaine. US guided PVBs were typically performed at levels T1, 3, and 5. Sedation was typically provided with propofol +/- ketamine. Opioids were provided at the discretion of the anesthesia team caring for the patient. Via retrospective review, we examined multiple perioperative outcome measurements. Data analysis was accomplished with either a t-test or chi-squared test as appropriate.

Results: Baseline patient characteristics were similar between the two local anesthetic groups with the exception of preoperative opioid consumption which occurred more frequently in the ropivacaine group(table 1). Patients in the bupivacaine group required unplanned conversion to GA in 8.2% of cases whereas unplanned conversion to GA in the ropivacaine group occurred in 0% of cases. Phase I and II data was similar between the different local anesthetic techniques. Rates of nausea in Phase I and II were low and similar regardless of anesthetic technique. Hospital admission occurred significantly more frequently in the bupivacaine (31.6%) than the ropivacaine (7.1%) group. In those patients requiring hospital admission following their outpatient breast surgery, POD #1 nausea and 24 hour opioid consumption were similar between the two groups(table 2).

Discussion: Our results indicate that US guided PVBs can be effectively used to avoid GA. Our results also indicate that both bupivacaine and ropivacaine perform well when performing US guided PVBs. Increased rates of hospital admission in the bupivacaine group are surprising but may indicate that those patients were scheduled to undergo surgical procedures of increased complexity and that influenced the local anesthetic choice of the regional anesthesiologist. Given that this is a retrospective study, selection bias and varying intraoperative management strategies exist. Therefore, future randomized controlled studies that evaluate local anesthetic choice for US guided PVB are necessary.

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DOES THE FASCIAL "CLICK" SENSATION DURING LATERAL POPLITEAL SCIATIC BLOCK CORRELATE WITH SUB-EPINEURAL INJECTION? EVALUATION OF LOCAL ANESTHETIC SPREAD UTILIZING 3D ULTRASOUND. A. Missair, R.E. Gebhard Anesthesiology, Univesity of Miami - Jackson Memorial Hospital, Miami, FL, USA Introduction:

The sensation of a fascial "pop" or click has been described in the literature during the placement of a lateral popliteal sciatic nerve block as the needle is advanced past the fascia of the biceps femoris muscle (1,2). The evaluation of local anesthetic spread after popliteal sciatic nerve block has been compared after sub-epineural injection versus injections made outside of the epineurium in terms of nerve injury (3). Several authors demonstrated no clinical or electrophysiologic evidence of neurologic injury after intraneural injection (3). We hypothesize that the sensation of a fascial "pop" correlates with the appearance of sub- epineural injection after an ultrasound guided lateral popliteal sciatic block.

Materials and methods:

After IRB approval, a total of 60 patients are projected to be enrolled in this prospective randomized double blinded clinical trial. This is a preliminary analysis of the first 21 patients. Each patient was randomly assigned to either the sub-epineural (Group SI) or the extrafascial injection (Group EF). Ultrasound-guided lateral popliteal nerve blocks were placed using a 22-gauge 100mm insulated needle (BBraun, Bethlehem, PA) with an in-plane approach at the level of the sciatic bifurcation. Depending on group assignment, the needle tip was placed outside or beneath the sciatic sheath for a single injection of 30mL of 0.5% ropivacaine. Using 3D Ultrasound imaging (BK Medical, Herlev, Denmark) with a 12-MHz linear probe, post-block scans of the sciatic nerve were obtained 50mm proximal and 50mm distal to the point of injection. The feeling of a "pop" was recorded by the anesthesiologist performing the block. Sensory block to pinprick was assessed in 5-minute intervals for 30 minutes in the peroneal and tibial nerve distributions by a blinded research assistant. Blocks were characterized as successful if a sensory block to both nerve components was achieved within 30 minutes. Post-injection spreads were used to analyze if the injections were correctly placed SI versus EF. Data was analyzed using the chi-squared test.

Results:

The sensation of a fascial "pop" was felt in 90% of patients in group SI versus only 20% of patients in group EF producing a significant p-value of (p =0.035). When comparing groups SI and EF for sensory block, no significant difference between the techniques in producing a successful analgesic block was observed (p =0.82). Analyzing the 3D images post-injection yielded 100% of SI injections demonstrated laminar appearance along a longitudinal axis and 100% of the EF group had a globular distribution along the same axis. Conclusions:

The preliminary results of this study demonstrate that the sensation of a fascial "pop" in the performance of a lateral popliteal block corresponds to a subepineural injection by ultrasonographic imaging. Our data also illustrated that there was no difference in SI versus EF lateral popliteal sciatic blocks in terms of achieving an analgesic block within 30 minutes.

References:

1 Bigeleisen PE. Anesthesiology 2006;105:779-83

2 Brull R et al. Reg Anesth Pain Med 2011;36:266-70

3 Sala-Blanch X. Anesthesiology 2011;115:589-95

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THRESHOLD CURRENT NECESSARY TO PRODUCE A MOTOR RESPONSE DURING THE PERFORMANCE OF POPLITEAL SCIATIC BLOCK M. Davidov, S. Bhatt, V. Bazalitski, G. Filatoff Anesthesiology, University of Toledo Medical Center, Anesthesiology, Toledo, Toledo, OH, USA Introduction: When performing a nerve block with nerve stimulator guidance a current at or below 0.5 mA is considered a satisfactory end point. However it has been demonstrated that even when nerve needle contact has been demonstrated using ultrasound (U/S), a current greater than 0.5 mA may be necessary to produce a motor response and yet result in a satisfactory nerve block. We have conducted the following study to determine the threshold current necessary to produce a motor response at the time of a nerve needle contact demonstrated using U/S. Method: After IRB approval, and an informed consent, thirty adult patients scheduled to undergo a popliteal sciatic nerve block for either surgical anesthesia or post operative pain control were enrolled. After application of monitors and sedation with midazolam iv, patients were placed in the prone position. The sciatic nerve was identified at the site of its division using U/S (SonoSite, Bothell, WA). We used a 35 mm 7-11 MHz linear probe. Using real time U/S guidance a 50-mm, 22 G stimuplex needle was introduced in- plane until nerve-needle contact was visualized. Slowly increasing current (2 Hz) was applied using a nerve stimulator (Stimuplex, B.Braun Medical Inc.) until a motor response was identified in one of the muscles supplied by the common peroneal nerve or a current intensity of 1.5 mA was reached. Needle was held still and 20 cc of 0.5% bupivacaine was injected incrementally over 1-2 minutes. Sensory block was assessed at 30 minutes following the injection. Results: Four subjects had no discernible motor response even at a current intensity of 1.5 mA. Of the 26 subjects demonstrating a motor response the mean current requirement to produce a motor response was 0.74±0.27 mA. Three subjects required a current greater than 1 mA to produce a motor response. Three subjects had a motor response at nerve needle contact, even though the applied current was set below 0.4 mA. All subjects had loss of sensation to pin prick 30 minutes following injection Conclusion: There appears to be a large variability in the threshold current required to produce a motor response at the point of U-S nerve needle contact during a popliteal sciatic block.

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A COMPARATIVE ASSESSMENT OF ARTERIAL BLOOD FLOW CHANGES FOLLOWING ULTRASOUND GUIDED BRACHIAL PLEXUS AND STELLATE GANGLION BLOCKADE C.J. Voscopoulos, K. Meecham, B. Bowman, M. Byas-Smith Department of Anesthesiology, Critical Care, and Pain Medicine, Emory University School of Medicine, Department of Anesthesiology, Critical Care, and Pain Medicine, Emory University School of Medicine, Atlanta, Department of Anesthesiology, Critical Care, and Pain Medicine, Atlanta, Atlanta, GA, USA A Comparative Assessment of Arterial Blood Flow Changes Following Ultrasound Guided Brachial Plexus and Stellate Ganglion Blockade Christopher Voscopoulos, MD; Kathleen Meacham, PhD; Brandon Bowman, MD and Michael Byas-Smith, MD Brachial plexus blockade has been used to induce sympathectomy-like effects to counteract vasospasm, increase regional blood flow and reduce pain for a variety of clinical conditions including frostbite injury, insect bites, CRPS and vasospastic disease. We hypothesized that dense brachial plexus blockade induces only partial sympathectomy-like conditions and that stellate ganglion blockade may be necessary when near complete sympathectomy-like conditions are demanded.

Methods: Six patients with end-stage renal disease with native kidneys intact undergoing upper extremity arterial-venous fistula or graft insertion under brachial plexus block consented to participate in this study. Changes in axillary artery blood flow after nerve block, measured via the ultrasound Doppler technique, were used as a surrogate for relative sympathetic tone. Blood flow measurements were acquired immediately before and 30 minutes after an ultrasound guided supraclavicular brachial plexus block was performed with 10 cc, 0.5 % bupivacaine solution. Then an ultrasound guided ipsilateral stellate ganglion block (C6-7 tubercle) was performed with 5 cc, 0.5% bupivacaine solution. Blood flow measurements were repeated 30 minutes after ganglion injection and in the recovery room following surgery. To assess time and period effects, additional subjects were enrolled in two control groups and received only the supraclavicular brachial plexus block or no nerve blockade.

Results: As shown in Graph 1, the mean percentage increase in arterial blood flow was 47% (±20, sd) after the supraclavicular block and 117 % ( ±34, sd) after the stellate ganglion block. In these patients, artery diameter remained constant (data not shown). However, the velocity of blood increased, thus contributing the major factor for increased blood flow. In the control groups, blood flow increased significantly 30 minutes after the supraclavicular block group but trended downward after subsequent measures. There was no significant change in the non-blocked group.

Conclusion: Supraclavicular blockade increases blood flow to the upper extremity, however, the effect maybe short lived. Stellate ganglion blockade induced an average increase in blood flow that at least doubled the flow increases seen with the use of supraclavicular block alone. Blood flow increases are probably due to vasodilation at the distal small diameter arterial beds. When near complete sympathetic blockade is the therapeutic objective, peripheral neural plexus blockade may be insufficient and sympathetic ganglion blockade should be utilized.

REFERENCES

1. Shemesh D, Olsha O, Orkin D, Raveh D, Goldin I, Reichenstein Y, Zigelman C. Sympathectomy-like effects of brachial plexus block in arteriovenous access surgery. Ultrasound Med Biol 2006;32:817-22

2. Mollison HL, McKay WP, Patel RH, Kriegler S, Negraeff OE. Reactive hyperemia increases forearm vein area. Can J Anaesth 2006;53:759-63

3. Su HH, Lui PW, Yu CL, Liew CS, Lin CH, Lin YT, Chang CH, Yang MW. The effects of continuous axillary brachial plexus block with ropivacaine infusion on skin temperature and survival of crushed fingers after microsurgical replantation. Chang Gung Med J 2005;28:567- 74

4. Szili-Torok T, Paprika D, Peto Z, Babik B, Bari F, Barzo P, Rudas L. Effect of axillary brachial plexus blockade on baroreflex-induced skin vasomotor responses: assessing the effectiveness of sympathetic blockade. Acta Anaesthesiol Scand 2002;46:815-20

5. Ebert B, Braunschweig R, Reill P. Quantification of variations in arm perfusion after plexus anesthesia with color doppler sonography [in German]. Anaesthesist 1995;44:859-62

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PRIMARY RESEARCH PUBLICATION TRENDS IN REGIONAL ANESTHESIA AND PAIN MEDICINE J.M. Groth, K.M. Schroeder Department of Anesthesiology, University of Wisconsin School of Medicine and Pub, Madison, WI, USA Introduction: Regional Anesthesia and Pain Medicine (published under the name Regional Anesthesia until 1998) has been in publication since 1976. The journal was originally distributed freely to all ASRA and ASA members. The first issue contained only ten pages and subsequent editions were published quarterly. From this humble beginning, Regional Anesthesia and Pain Medicine has evolved into a bi-monthly publication with an increasing impact factor and status within the anesthesia community. This study investigated the changing contributions to Regional Anesthesia and Pain Medicine throughout the years.

Methods: The journal Regional Anesthesia and Pain Medicine (formerly Regional Anesthesia) was reviewed at 5 year intervals between 1995 and 2010. For each primary research article contained within the journal, the type research method was documented. Articles were assigned by one evaluator (JG) and primary research was grouped into five categories (animal studies, controlled clinical trial, laboratory, randomized control trial and other design). We also evaluated Impact factor data from 1995 through 2010 for Regional Anesthesia and Pain Medicine.

Results: At five year intervals between 1995 and 2010, the impact factor for Regional Anesthesia and Pain Medicine steadily increased. Missed in the five year interval analysis is a drop in impact factor in 1999 related to the change in journal name. Between 1995 and 2010, the number of animal studies nearly doubled. The number of controlled clinical trials increased dramatically from 1995 to 2010 (1.7% to 7.2% of primary research publications). Laboratory studies increased from 1.7% in 1995 to 3.6% in 2010. Randomized control trials fell from 49.1% of primary research publications in 1995 to 34.5% in 2010.

Discussion: Anesthesiologists interested in pain management are fortunate to have a quality publication like Regional Anesthesia and Pain Medicine to showcase high quality developments within the field. Our research demonstrates that primary research publications in Regional Anesthesia and Pain Medicine have remained a staple over the past fifteen years. Increases in the journal's impact factor have occurred as the percentage of primary research articles that were animal and laboratory studies have also increased. This increase in journal impact factor has also occurred while the percentage of randomized controlled trials has decreased. While these publication trends may have important implications with regard to impact factor scores, animal and laboratory studies may not be what draws the practicing physician to read Regional Anesthesia and Pain Medicine. Over the same time period, the number of narrative and systemic reviews increased dramatically which could help provide the clinically relevant data desired by a large number of practicing physicians. While this data does represent only snapshots in time over the last 15 years of publication of Regional Anesthesia and Pain Medicine, it does illustrate publication variations.

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OPIOID SPARING EFFECT OF INTRAVENOUS ACETAMINOPHEN IN A RETROSPECTIVE COHORT OF PEDIATRIC PATIENTS R. Pickering, J. Steiner, D. Walsh, P. Szmuk Anesthesiology, University of Texas Southwestern Medical Center, Dallas, TX, USA Introduction:

Intravenous (IV) acetaminophen was approved by the US FDA in November 2010 for use in pain management or reduction of fever in children from age 2 years and older. In numerous randomized, controlled trials involving a variety of surgeries, IV acetaminophen was shown to provide rapid and effective pain relief in patients with acute pain.1 Following the addition of IV acetaminophen to the hospital formulary, a retrospective chart review was conducted in surgical pediatric patients to determine patterns of opioid and antiemetic use. Methods: This planned retrospective study was conducted with approval of the IRB of UT Southwestern Medical Center, Dallas, TX. All pediatric patients from March 11 to October 24, 2011, anesthetized by one of the authors (PS) who received open-label IV acetaminophen were included in the analysis as a single group. In all patients, inhalational anesthetics were used and analgesia was managed using IV acetaminophen, and intra- and post- operative opioid analgesics. Antiemetics were administered when deemed necessary. In the post anesthesia care unit, rescue opioids (morphine, fentanyl, oxycodone or meperidine) were available to all patients on a p.r.n. (as needed) basis. A single dose of IV acetaminophen was administered intraoperatively at the following doses by age group: patients < 2 years old received 10 mg/kg; patients ≥2 years old or children and adolescents weighing < 50 kg received 15 mg/kg; and patients weighing > 50 kg received 1 g. Patient charts were reviewed for the following information: demographics, intraoperative medications, inpatient or outpatient status, perioperative medications, use of antiemetics and incidence of nausea or vomiting (as recorded by the nurse in the recovery room). Descriptive statistics were summarized. Statistical analysis was conducted using the Chi Square test. Results: A total of 103 patients (ASA I-III; age 9 months to 17 years; 56M/47F) were identified as receiving IV acetaminophen and their charts were reviewed. Approximately half of the patients were outpatients (n=55). For patients < 2 years old (n=6), mean weight was 10.4 kg and mean age was 0.9 years. For patients ≥2 to 12 years old (n=73), mean weight was 27.0 kg and mean age was 6.2 years. For patients ≥13 years old (n=24), mean weight was 65.5 kg and mean age was 14.9 years. A wide variety of surgical procedures were included: minor orthopedic, plastics, urology, dental rehabilitation, esophagogastroduodenoscopy, ENT procedures, and general surgery procedures. Of the 103 patients, 29 (28%) did not require opioid analgesics either intraoperatively or postoperatively. Antiemetics were administered to 11 (38%) of these patients. Of the remaining 74 cases which received an opiate analgesic during the perioperative period, 51 (69%) were administered antiemetics (prophylactically or at request). Antiemetic use in patients who did not require opioid analgesics was significantly less (p=0.004) compared with those who did require opioids. Discussion: In this group of surgical pediatric patients receiving IV acetaminophen, nearly a third did not require opioids either intraoperatively or postoperatively, demonstrating that an opioid-free approach can be viable in this population. Patients who were administered opioid analgesics were more likely to require antiemetics as compared with those who received only IV acetaminophen. As this is a retrospective single-site study, these results must be interpreted with caution. Nonetheless, our results support the hypothesis that a reduction in or avoidance of opioid consumption may reduce the need for antiemetic medication. References: Duggan ST, Scott LJ. Intravenous Paracetamol (Acetaminophen). Drugs. 2009;69(1):101- 113.

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THE BENEFITS OF THE TAP BLOCK IN ENHANCED RECOVERY FOR LAPARASCOPIC RADICAL PROSTATECTOMY SURGERY J.S. Bhular, T.J. Dudderidge, S. Agrawal, M.H. Winkler, P. Doyle Anaesthetics, Charing Cross Hospital, Imperial College Healthcare NHS Trust, Urology, Imperial College Healthcare NHS Trust, Urology, London, Anesthesia, Imperial College Healthcare NHS Trust, London, UK Background and Goal of Study:

Length of stay (LOS) has been proposed as a direct measure for the quality of major procedures1. Following laparoscopic surgery patients may suffer from postoperative symptoms of pain, nausea and opioid hang-over, these symptoms may require interventions that prolong LOS. The Transversus Abdominis Plane (TAP) block has been described for open radical prostatectomy patients2, reducing both morphine requirements by 70% and PONV by 50%. We evaluated the role of the TAP block in Laparoscopic extraperitoneal Radical Prostatectomy (LRP) versus standard morphine analgesia using LOS and morphine consumption as end points. Materials and methods:

We prospectively collected data on our first 200 consecutive patients undergoing LRP. The initial 100 patients underwent GA with morphine analgesia, the subsequent 100 patients underwent GA with a pre-procedure TAP block with rescue morphine analgesia. An audit of analgesia use and postoperative pain was conducted before and after introduction of bilateral TAP blocks. The audit consisted of 20 pre-TAP and 59 post-TAP patients (n=79). Pain was assessed in the ward using a categorical pain scoring system with visual aids3. Data was collected on duration of stay and surgical complications.

Results and discussion:

Table 1

156 (78%) men were one night stay patients and 14 (7%) were true day-cases, all occurred in the TAP block cohort.

Conclusion:

The introduction of the TAP block onto our care pathway led to a significant reduction in morphine use. Reducing or avoiding morphine use avoids some of the postoperative problems that can delay discharge. Early discharge after LRP brings benefits to both patients and healthcare providers through an earlier return home and a reduction of inpatient costs. Following the audit TAP blocks were routinely performed in all patients.

References:

1.Birkmeyer JD, Dimick JB, Birkmeyer NJ. Measuring the quality of surgical care: structure, process, or outcomes? J Am Coll Surg 2004:198(4):626-632.

2.O´Donnell BD, McDonnell JG, McShane AJ. The transversus abdominis plane (TAP) block in open retropubic prostatectomy. Reg Anesth Pain Med 2006:31(1):91.

3.Royse CF, Newman S, Chung F, et al. Development and feasibility of a scale to assess postoperative recovery: the post-operative quality recovery scale.Anesthesiology 2010:113(4):892-905.

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TANSVERSE INFRACLAVIULAR APPROACH TO THE BRACHIAL PLEXUS - MEACV N. Lam, V. Chan, C. Arndt, R. Rosett, F. Vagh Anesthesiology, University of New Mexico, Albuquerque, NM, USA, University of Toronto, Toronto, ON, Canada, University of New Mexico, Albuquerque, Albuquerque, NM, USA Introduction:

Arm abduction has been shown to optimize the ultrasound (US) view of the brachial plexus during an infraclavicular block (ICB) with in-plane insertion of the needle in the parasaggital plane.(1) However, both needle and target visualization with this technique may still be challenging. We describe a new approach that has been used at our institution for the past 4 years. This involves transverse placement of the ultrasound probe in the delto-pectoral groove, which provides an oblique short axis view of the artery and cords. The potential advantages are: a) improved nerve anisotropy control in the coronal plane, b) a shallower angle of in-plane needle insertion, and c) improved visualization of the lateral, medial and posterior cords, all lateral to the artery, without significant acoustic enhancement obscuring the posterior cord. Figure 1 shows a saggital view with the arm abducted and figure 2 shows a transverse view with the arm abducted.

The minimum effective volume for 95% of the population using US-guided ICB has been recently reported to be 33 mL (MEAV95) using 0.5% ropivacaine. (2) To date, there are no studies on the minimum effective concentration of ropivacaine required to produce surgical anesthesia using an ultrasound (US) guided infraclavicular block (ICB).

Inclusion criteria:

ASA I-III, BMI< 35 and >18 years old for upper limb surgery not involving the shoulder

Technique

Patients were sedated with midazolam and fentanyl to achieve anxiolysis while maintaining verbal contact. All blocks were performed by 1 of 5 regional anesthesiologists with expertise in US-guided ICB block and who were blinded to the local anesthetic concentration.

ICB were performed with the patient lying supine and the arm abducted to 90 degrees. A 28mm high frequency ultrasound probe was placed in the delto-pectoral groove parallel to the clavicle. A 22-gauge, 80 mm Touhy needle was inserted at the lateral border of the probe using an in-plane technique without nerve stimulation. 33 ml of LA was injected to achieve circumferential spread around the individual cords of the brachial plexus. Care was taken never to inject intraneurally as indicated US evidence of nerve swelling or pain/pressure on injection. The starting concentration was 0.5% ropivacaine.

Sensation to ice was tested by a blinded assessor in the median, ulnar, radial and musculocutaneous nerve distributions every 5 minutes. Block success was defined as complete loss of sensation to ice in all 4 nerve distributions within 30 minutes. These patients proceeded with surgery under monitored anesthetic care (MAC). Depending on block failure or success for the previous patient, the volume administered to the next patient was adjusted up or down by 0.05% respectively.

Results:

We applied Dixon and Massey's up-and-down statistics with small sample size, stopping the study at 4 data points after the first failure. (4) We completed 11 patients with the first failure at 0.2% ropivacaine. (Graph 1) As such, our ED 50 was 0.157%; 95% CI (0.074,0.239) and the ED95 was found to be 0.263%

All patients were followed up within 48 hours and sensation had returned to normal.

Conclusion:

33 ml of 0.263% ropivacaine is sufficient to produce insensate upper limb for surgery in 95% of the population when US-guided ICB is conducted by experts in the technique. References:

1) Bigeleisen P, Wilson M. A comparison of two techniques for ultrasound guided infraclavicular block. Br J Anaesth. 2006 Apr;96(4):502-7. Epub 2006 Feb 24.

2) Zhang XG, Li L, Liao J, Xu T, Feng L, Li SZ. [Ropivacaine volume for ultrasound-guided retrograde infraclavicular brachial plexus block].[Article in Chinese]. Zhonghua Yi Xue Za Zhi. 2010 Aug 17;90(31):2209-11.

3) Soares LG, Brull R, Lai J, Chan VW. Eight ball, corner pocket the optimal needle position for ultrasound-guided supraclavicular block. Reg Anesth Pain Med. 2007;32:94-95.

4) Dixon WJ, Massey FJ. Introduction to Statistical Analysis. 4th ed. New York, NY: McGraw-Hill; 1983:377-394.

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COMPARATIVE ESTIMATION OF MORPHOLOGICAL CHANGES OF SEGMENTS AND NERVOUS BACKS SPINAL CORD AT ELECTRONEUROSTIMULATION IN RABBITS V M.U. Daulet, J.K. Ramazan, K.S. Yerkin, M.O. Galina, M.D. Yernar Course of anesthesiology and reanimatology, Pavlodar branch of State Medical University of Ast, Astana, Course of anesthesiology and reanimatology, State Medical University of Semey city, Semey, Pathoanatomical department, Pavlodar city, Course of anesthesiology and reanimatology, Pavlodar branch of State Medical University of Se, Pavlodar, Kazakhstan Course of Anesthesiology and resuscitationof Pavlodar branch of State Medical University(SMU) of Semey c., pathoanathomical dep. of Hospital №1 of Pavlodar c., Kazakhstan Background. In recent years, has received widespread method for finding electroneurostimulation peripheral nerve and plexus block anesthesia for a surgery that uses small currents, low frequency and duration. On the other hand the method of ENS has not been used for spinal anesthesia. Data on the impact of current low-power and low frequencies produced by these devices, the neural structures located in the subarachnoid space of the spinal cord, we did not find. The study was conducted with the permission of the Ethics Committee of the State Medical University of Semey city from 01.08.2009.

Objective. The experimental work was devoted to the study of morphological changes of the spinal cord and nerve roots of cauda equina of spinal cord in rabbits under the influence of the current rectangular force of up to 3 ma with a pulse duration of 0.1 ms and a frequency of 1.2 Hz using elektroneurostimulator. Studied the morphological changes of the spinal cord and nerve roots of cauda equina spinal cord at different levels in rabbits after exposure to shock 3ma, pulse width 0.1 ms and a frequency of 2 Hz for 15 seconds, 30 seconds, 1 minute, 3 minutes and 5 minutes.

Methods. The experimental part of the work was carried out on 16 rabbits weighing from 2.5 to 3 kg, kept on normal feeding regime in vivarium conditions (Figure1-3). As the anesthetic used 5% solution ketamin 6 mg/kg of animal body weight.

To solve the problem of the present study animals were divided into groups VI. Group I (control) consisted of rabbits was injected into the subarachnoid space of 0.9% isotonic sodium chloride at a dose of 1 ml / kg. The rest of the rabbits produced subarachnoid space puncture needle for conductive anesthesia Stimuplex size 22G, 50 mm in length, which connects to elektroneurostimulator Stimuplex-DIG.

Results. At histological sections animals I-IV groups represented a cross section of nervous tissue of spinal cord corresponds to the normal histological structure. The animals on the transverse sections of spinal cord were manifestations of light dystrophy, which appeared heterogeneity of the cytoplasm of nerve cells and an increase in edema in the intercellular substance. Impact of electric current of low power from 2 to 3ma, short duration - 0.1 ms and low frequency - 2gerts during 15 sekond, 30 seconds, 1 minute and 3 minutes did not lead to significant pathomorphological changes in tissues of spinal cord and nerve roots of cauda tail spinal cord in rabbits. In slices observed swelling cells with irregularly stained cytoplasm, destruction of cell nuclei was observed. In sections of spinal roots, presented fiber bundles, there are moderately enlarged space at the expense of unpainted edema.

Conclusions. Degenerative changes in segments of spinal cord cells on histological sections, begin to appear in the case of ENS with a current of 3 ma for 5 minutes. Pathological changes in nerve fibers of the cauda equina of spinal cord was not.

References:

1. Nazarov G. Forensic investigation of electric shock. 1992; 144.

2. Regional anesthesia. James R. Rafmell, Joseph M. Neal, Christopher M. Viskoumi. 2007; 151-167.

3. Eliseev V.G., Afanasiev Y.I., Kotovsky E.F. Atlas of microscopic and ultramicroscopic structure of cells, tissues and organs .- Moscow. - Medicine. - 1970, 122-202.

4. Merkulov G.A. The course of histopathological techniques. M. Medgiz. 1961, 144-265.

5. Trifonov E.I. Human Physiology. Russian-English-Russian entsiklopediya.13 edition. 2009.

6. Ham, A., Cormack D. Histology .- Moscow - The World. 1982: (3 volume).

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ULTRASOUND GUIDED OUT OF PLANE PARAVERTEBRAL BLOCKADE: A NEW VARIATION ON AN OLD TECHNIQUE R.A. Jacobs, K.M. Schroeder, M.P. Ford, T. Broderick, B. Anderson, M.J. Donnelly Anesthesiology, University of Wisconsin, Madison, WI, USA Background: Paravertebral blocks are a proven option for unilateral chest procedures. Multiple approaches have been described in the literature over the past decade. Ultrasound guidance has allowed anesthesiologists to place these blocks with a greater degree of confidence. We propose a simplified out of plane approach with a parasagittal ultrasound probe position.

Methods: Following IRB approval, we reviewed the charts of 150 patients who underwent ultrasound guided paravertebral blockade for breast surgery. These included 22 simple mastectomies, 106 lumpectomies, 11 modified radical mastectomies, and 11 lymph node dissections. Exclusion criteria included incomplete documentation, intra-operative use of remifentanil or alfentanil, and planned general anesthesia. Patients were positioned in the sitting position. A Zonare® L14-5w linear array ultrasound probe (Zonare Medical Systems, Mountain View, CA) was placed in a parasaggital orientation. Then using an out-of-plane needle (50 or 100mm Pajunk UniPlex NanoLine® needle (Pajunk, Geisingen, Germany)) approach with saline for hydrodissection, paravertebral blocks were placed. A total of 30 milliliters of 0.5% Bupivacaine with Epinephrine 1:400,000 was injected at each thoracic level.

Results: We found a block failure rate of 5.3% (defined as a conversion of regional to a general anesthetic). 86.7% of patients were able to bypass Phase I recovery and go directly from the operating room to Phase II. Total post-operative morphine equivalent usage was 1.857mg + 3.165. Mean pain score was 1.754 (1-10 scale) + 1.397. Post-operative nausea rate was 4.66%.

Conclusion: An out-of-plane parasagittal probe oriented ultrasound guided technique for paravertebral blocks is a safe and simplified version of previously described techniques.

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CONTINUOUS PARAVERTEBRAL CATHETERS AND MINIMALLY INVASIVE CARDIAC SURGERY G. Skoropowski, B. Pearce-Smith, L. Wei, J. Chelly Anesthesiology, Univesity of Pittsburgh Medical Center, Cardiothoracic Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pittsburgh, PA, USA Introduction: Surgery is increasingly performed using minimally invasive approaches including cardiac surgery. At the same time, it seems that in most institutions, epidural analgesia remains the technique of choice to provide effective peri-operative analgesia. In this regard, paravertebral blocks, a lesser invasive technique than epidural, have been demonstrated to be equianalgesic to epidural blocks. We are reporting our experience with the use of continuous paravertebral blocks (CPVBs) in patients undergoing minimally invasive cardiac surgery (MICS). Methods: Between 9/1/2008 and 11/30/2011, a total of 30 patients underwent MICS (Maze procedure, mitral valve replacement, or single vessel CABG procedures with CPVBs) with CPVBs. In each patient, CPVBs were performed prior to surgery. Depending on the type of surgery, the paravertebral catheters were placed unilaterally or bilaterally at levels T3 or T4. During the placement of each catheter, a bolus with 15 ml of ropivacaine 0.5% followed by an infusion of either lidocaine 0.25% (bilateral) or bupivacaine 0.0625% (unilateral) was infused. To assess the effectiveness of this approach, data were compared to a similar group of patients who did not benefit from a regional technique (control). Results: The use of CPVBs was associated with a 56% increase in the rate of extubation prior to leaving the operating room compared to the control group. In addition, the length of hospital stay was reduced by one day on average with an associated shorter ICU stay. Pain reduction at the 24 hour mark was reduced 44% compared to the control group. Discussion: Our data support the concept that the combination of CPVBs and minimally invasive cardiac surgeries facilitate a fast-track surgical pathway. References: 1. Carmona, P et al. J Cardiothorac Vasc Anesth. 2011 Feb;25(1):205-6 2. Carli, F et al. Reg Anesth Pain Med 2011:36: 63-72 3. Davies, R et al. Br J Anaesth. 2006 Apr;96(4):418-26 4. Joshi, G et al. Anesth Analg. 2008. Sep;107(3):1026-40 5. Lynch, J et al. Semin Cardiothorac Vasc Anesth. 2010 Mar;14(1):47-8 6. Modi, P et al. Eur J Cardiothorac Surg. 2008 Nov;34(5):943-52 7. Karmakar, M. Anesthesiology. 2001 Sep;95(3):771-80 8. Dhole, S et al.. J Cardiothorac Vasc Anesth. 2001 Jun;15(3):288-92

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SEE ONE, DO ONE, TEACH ONE…HOW BEST TO TEACH? A.K. Lansdown, S. Patel, P. McHardy, C. McCartney Anesthesia, Sunnybrook Health Sciences Centre, Anesthesia, sunnybrook Health Science Centre, Anesthesia, Sunnybrook Health Science Centre, Anesthesia, Toronto, Toronto, ON, Canada Introduction:

The recent renaissance of regional anesthesia (RA) has driven demand for more training in this field. In response, the number of RA fellowship programs has risen. Although guidelines for training in RA exist, there is no requirement to follow them when developing a fellowship program. As a result the clinical and theoretical instruction offered in these programs may vary. Although didactic teaching along with hands on patient care has been the tradition in medical education, with limited time and competition for clinical experience, as well as the ethical concerns of learning on patients, other practical education activities have developed. One example is cadaver sessions, which are popular with trainees and have been reported as useful educational tool in anesthetic and surgical literature. We performed a survey of RA fellowship directors to determine the scope of educational activities offered in international RA fellowship programs.

Methods: An online questionnaire was sent to 68 international RA fellowship directors over 2 months in late 2011. Questions related to the range of education, experience and evaluation offered in their programs.

Results: Overall there were 37 respondents (54% response rate) with 1 who did not have an RA program at present. Of the 36 RA fellowships, 32 (89%) reported scheduled education time for their fellows - the median time allocated per week was 4 hours. 22 (61%) rated formal education during RA fellowship training either extremely or very important. Didactic and practical educational activities were both widely used. Overall, live model sonography was the most commonly utilized educational activity in 29 (81%), followed by journal club and EBM review in 28 (78%). Only 24 (67%) offered a lecture series while cadaver dissection were utilized in 18 (50%) programs. Of these, cadaver sonography was practiced in 12 (67%). Educational resources are generally widely available to fellows. US phantom models are available in 29 (81%), textbook and journal library in 35 (97%), educational websites in 28 (78%) and 3D-anatomy software in 9 (25%). 22 (61%) utilize non-anesthesia staff in the delivery of their educational program.

Conclusions: Overall attitudes and allocation of time to educational activities in RA fellowships is encouraging. Most programs provide a good balance of didactic and practical education modalities. Lecture series might be underutilized in some programs, especially since it is inexpensive, efficient and easy to schedule method for knowledge translation. Ideally, cadaver training would also be offered more widely. It can provide the Fellow with anatomical knowledge and confidence in a variety of block techniques, even those not commonly performed in their institution, without the potential for patient injury or time pressure of the clinical environment. A major barrier to widespread use of cadavers is cost, especially taking into account the limited number of potential participants. Collaboration between programs may assist in course planning and cost containment, making this educational tool more accessible to RA fellows. On the other hand availability of 3D- computer software might fill this learning gap and be more cost effective and easier to administer in the longer term.

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REIMBURSEMENT FOR REGIONAL ANESTHESIA IN A BUNDLED PAYMENT ENVIRONMENT: A VALUE PROPOSITION S. Sinha, J. Abrams Anesthesiology, St.Francis Hospital and Medical Center, Anesthesiology, St. Francis Hospital and Medical Center, Hartford, CT, USA Introduction:

The bundled payment model, which coalesces reimbursement to multiple providers into a single payment, is a strategy that is being advocated to align incentives and control the rising costs of health care. This approach encourages hospitals and physicians to create a more efficient patient care model designed to reduce variability, coordinate care, focus on quality and outcomes, and increase patient satisfaction by creating mutual accountability among providers.

Method:

We describe our experience in developing a Bundled Payment reimbursement model for total joint arthroplasty anesthetic services in partnership with our surgeons and hospital. Following development of a formal operating agreement, each party was charged to determine the fair market cost for their services and then negotiate a single price for total hip arthroplasty and total knee arthroplasty procedures. To accurately determine anesthesia costs, we measured the time utilized in delivering our services for arthroplasty patients. The time required for preoperative assessment, placement of peripheral nerve blocks, intra-operative management and follow up care was assessed. Once external valuation of hourly “anesthesiologist reimbursement” was obtained, a standard profit margin for each of the participating entities was added to the overall bundle; the hospital, surgeons and anesthesiologists shared proportionate payment as well as proportionate risk for costs of readmissions related to perioperative complications.

Discussion:

The current method of payment for anesthesia is likely to change in the foreseeable future from a fee-for-service model to bundled payment where the cost, profits and risks will be shared with surgeons and hospitals. Our experience suggests that there will be persistent downward pressure on incremental reimbursement for regional anesthesia as it is subsumed within global fees for anesthetic services. To maintain reimbursement for regional anesthesia, we encourage our colleagues to collectively develop a portfolio of evidence-based research to support the value of regional anesthesia in improving patient outcome and decreasing cost of patient care. The value of regional anesthesia can only be realized if surgeons and hospitals understand its importance in maintaining quality of care and patient satisfaction. We should proactively define the value of regional anesthesia and acute pain service rather than permit “global” anesthesia services to be predetermined for us. If we are complacent, the value of regional anesthesia will be lost in the discussion.

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INCIDENCE OF HEMIDIAPHRAGMATIC PARESIS AFTER COMBINED INTERMEDIATE INTERMEDIATE AND SUPERFICIAL CERVICAL PLEXUS BLOCK FOR CAROTID ENDARTERECTOMY S. Renes, D. van Aalst, G.-J. van Geffer, G.-J. Scheffer Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands Incidence of hemidiaphragmatic paresis after combined intermediate intermediate and superficial cervical plexus block for carotid endarterectomy

Introduction

Intermediate cervical plexus block (CPB) and superficial CPB are equally effective for carotid endarterctomy(1), while these regional anesthesia techniques are associated with a reduced incidence of complications compared to a deep CPB (2). Combined deep and superficial CPB is asscociated with hemidiaphragmatic paresis in 61% of the patients whereas a superficial CPB for parathyroidectomy is not associated with hemdiaphragmatic paresis(3). The incidence of hemidiaphragmtic paresis after combined superficial and intermediate CPB is unknown.

Methods

16 patients scheduled for carotid endarterectomy under combined intermediate and superficial CPB using 30 mL ropivacaine 0.5% were investigated. An intermediate CPB was performed with 10 mL ropivacaine 0.5% at the midpoint of the posterior border of the sternocleidomastoid muscle until a “plop” was encountered with the needle at a depth of 1-2 cm. Subsequently the needle was redrawn to a maximum depth of 5 mm and ropivacaine 0.5% was injected superficially along the entire length of the posterior border of the sternocleidomastoid muscle with; 10 mL was injected in the cranial direction and 10 mL in the caudal injection. Intra-operative supplementation with lidociane 1% was noted.

Diaphragmatic movement by real-time M-mode ultrasonography of the hemidiaphragm using a 17-mm 1- to 5-MHz broadband phased array US probe (SonoSite P17) was evaluated. (4) Diaphragmatic movement reduction of more than 75%, no movement, or paradoxical movement was considered to be "complete paresis." Diaphragmatic movement reduction of both sigh and sniff test between 25% and 75% was considered to be "partial paresis" and diaphragmatic movement of less than 25% was considered to be "no paresis." Measurements were before (baseline) and 15, 30 after CPB performance and 1 hour post-operative.

The anterior surface of the anterior scalene muscle and the phrenic nerve were ultrasonographically assessed at the level of roots C6 and C7 using a 38-mm, 6- to 13-MHz broadband linear array US probe (SonoSite HFL). The US images were made before; at 15 and 30 mins after CPB performance. The images were assessed for spread of local anesthetic to the phrenic nerve and/or the anterior surface of the anterior scalene muscle.

Results

In 9 (56%) patients local anesthetic was observed around the phrenic nerve; in these 9 patients hemidiaphragmatic paresis was observed (5 had complete en 4 partial hemidiaphragmatic paresis). In 5 patients (31%) intraoperative lidocaine 1% supplemention of the carotid sheath was necessary (range: 6-15 mL).

Discussion

Our preliminary results suggest that a combined superficial and intermediate CPB is associated with a 56% incidence of hemidiaphragmatic paresis, similar to the incidence of combined deep and superficial CPB.

1. Ramachandran SK, Picton P, Shanks A, Dorje P, Pandit JJ. Comparison of intermediate vs subcutaneous cervical plexus block for carotid endarterectomy. Br J Anaesth. 2011;107:157- 163.

2. Pandit JJ, Satya-Krishna R, Gration P. Superficial or deep cervical plexus block for carotid endarterectomy: a systematic review of complications

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A DECADE OF PERIPHERAL NERVE BLOCKS IN US HOSPITALS M.J. Young, S.A. Quraishi Department of Anesthesia, Critical Care and Pain M, Massachusetts General Hospital, Boston, MA, USA Introduction: Regional anesthesia and interventional pain management has witnessed a dramatic increase in popularity within the last decade. Our goal was to investigate whether inpatient length of stay and hospital charges associated with these procedures have changed over a 10-year period.

Methods: We queried the largest all-payer inpatient care database in the USAs to identify cases of hospital admissions between 2000-2009 with a principal procedure code of “injection of anesthetic into [a] peripheral nerve for analgesia” (ICD-9-CM: 04.81). This retrospective analysis was performed with data from the Healthcare Cost and Utilization Project (HCUP) National Inpatient Sample (NIS) repository. Data related to length of stay and hospital charges was extracted. 2000 and 2009 data for these variables were compared and further analyzed in SPSS v.19 (IBM Corporation, Amonk, NY) by age (18-44, 45-64, 65- 84, 85+), sex (male vs. female), hospital teaching status (teaching vs. non-teaching), and geographical location (Northeast, Midwest, South, West). Results are reported with ± standard error were applicable. p < 0.05 represented statistical significance.

Results: The number of weighted total discharges and discharges with a principal ICD-9-CM procedure code 04.81 within the NIS database were similar in 2000 and 2009. Average length of stay did not change significantly between these time points. Mean hospital charges were significantly lower in 2000 compared to 2009 ($14,272 ± 1,254 vs. $25,764 ± 1,738; p < 0.001). Length of stay did not change by age group between 2000 and 2009, but charges were uniformly higher for all age groups (p < 0.001). Although females were 1.8 times more likely (than males) to have a peripheral nerve block as the principal procedure related to hospital admission (p < 0.001), length of stay for females decreased significantly over the 10-year period (6.8 ± 0.4 vs. 5.4 ± 0.5; p = 0.3). This decrease in length of stay did not result in a significant cost reduction (when compared to males). Teaching hospitals witnessed a significant reduction in length of stay from 2000 to 2009 (7.8 ± 0.7 vs. 5.4 ± 0.5; p < 0.01), but similar reductions were not observed in non-teaching hospitals. Significant regional variations in the length of stay (p < 0.01) and hospital charges (p < 0.001) were observed in 2000, but were no longer apparent in 2009. Dramatic reductions in length of stay (2000 vs. 2009) only occurred in the Northeast (8.1 ± 0.6 vs. 5.4 ± 0.5; p < 0.001). Significant increases in hospital charges occurred in the Midwest and Southern regions (p < 0.001).

Conclusion: Our data suggest that patient age did not influence length of stay and charges related to hospital admissions for peripheral nerve blockade (ICD-9-CM 04.81) during a 10- year period. Although females witnessed significant reductions in hospital length of stay, this was not associated with expected decreases in mean hospital charges. Regional billing practices appear to be a major driver for global increases in hospital charges related to admissions for peripheral nerve blockade.

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SINGLE SHOT NERVE BLOCKS FOR MAJOR SHOULDER SURGERY: SUPRACLAVICULAR VS INTERSCALENE APPROACHES FOR POST-OPERATIVE PAIN CONTROL T. Nicholas, J. Johnson Anesthesiology, UNMC, Omaha, NE, USA Background

Both interscalene (IS) and supraclavicular (SC) nerve blocks have been shown to provide significant analgesia in patients undergoing upper extremity surgery. Individual studies have been conducted evaluating each block technique for post-operative pain control. As well, there have been studies comparing the two block techniques with regards to providing surgical anesthesia(1). However, no study has specifically compared which block provides superior post-operative pain control and patient satisfaction. In our proposed study we will attempt to compare these two block techniques.

Methods

Patients undergoing major shoulder surgery at UNMC were enrolled. Major shoulder surgery was defined as surgery requiring more than simple debridement or arthroscopy. Patients were excluded if less than 19 years of age, pregnancy, severe COPD, allergies to amide anesthetics, evidence of neurological dysfunction. The type of block was chosen by randomization. Ultrasound guidance was utilized with each block. A dosing regimen of 30cc of 0.5% ropivicaine and 150ug of epinephrine was used. All patients then underwent general anesthesia. An evaluation using numerical rating scales was performed in PACU and on post- op day 1.

Results

15 patients were enrolled. 5 patients in the IS group and 10 patients in the SC group. The surgical procedure makeup for each group was as follows: IS (60% total shoulder arthroplasty, 40% rotator cuff repair) and SC (60% rotator cuff repair, 30% total shoulder arthroplasty, 10% labral tear repair and arthroscopy).

The data was analyzed with the Exact Wilcoxon nonparametric test. Results indicated that the median patient satisfaction of the block while in PACU was larger with IS than SC (10 vs 9.5, p=0.12) and that median hours of block duration was smaller with IS than SC (9.5 vs. 13.5, p=0.08) (Fig. 1). However, there were no other trends towards statistical significance.

Conclusion

Initially, we believed there would be a difference between the blocks due to specific side effect profiles and characteristics. For instance, the IS block has been associated with an almost 100% incidence of hemidiaphragmatic temporary paralysis. In our study, 40% of the IS group and 20% of the SC group had perceived breathlessness while in the PACU. However, there was no statistically significant difference between the numerical scoring of breathlessness. The SC block has fewer incidences of phrenic nerve palsy but it is associated with generalized sensory and motor blockade. In one study, postoperative motor block of the hand was not tolerated by some patients(2). As well, the SC approach may theoretically not block lower roots of the cervical plexus. However, in our study there was no trend towards statistical difference between pain scores and overall satisfaction.

Understandably, the findings of this study are limited due to the small sample size. However, preliminary evidence suggests that both block types may be equally sufficient for post- operative pain control following major shoulder surgery.

References:

1. Liu SS, Gordon MA, Shaw PM, Wilfred S, Shetty T, YaDeau JT. A prospective clinical registry of ultrasound-guided regional anesthesia for ambulatory shoulder surgery. Anesthesia & Analgesia 2010;111(3):617.

2. Fredrickson MJ, Smith KR, Wong AC. Importance of volume and concentration for ropivacaine interscalene block in preventing recovery room pain and minimizing motor block after shoulder surgery. Anesthesiology 2010;112(6):1374.

[Figure 1] A117

SENSORY STIMULATION CHANGES WITH REPEAT RADIOFREQUENCY NEUROLYSIS FOR FACET ARTHROPATHY: AN OBSERVATIONAL STUDY V. Loomba, M. Gupta, D. Kim Department of Anesthesiology and Pain Management, Henry Ford Hospital, Detroit, MI, USA OBJECTIVES

To assess if any sensory stimulation changes exist with repeat Radiofrequency Ablation (RFA) for lumbar facet arthropathy.

BACKGROUND DATA

Facet arthropathy is a common cause of spine-related pain (1). Repetitive radiofrequency neurotomies have been reported previously as having a mean duration of relief of 10.5 months and were successful more than 85% of the time (2). Our present study reviewed if any sensory changes occurred with repeated RFA; and its effect on the length of efficacy and baseline pain as measured by the recurrence of symptoms.

METHODS

Record review of patients in our Pain Clinic who had an initial successful RFA, subsequent recurrence of pain, and then repeat RFA. The protocol in the pain clinic is that when patients have recurrence of pain to previous baseline, they call and are scheduled within 2 weeks for repeat RFA. 47 patients who received two or more RFA treatments were studied. The patient ages ranged from 38 to 92, with a mean of 56.5 +/- 12.2. The number of RFA treatments ranged from 2 to 15 (mean=5, median=4). The sensory voltages obtained for each RFA treatment and efficacy as measured by the duration between treatments were compared between RFTC instances by repeated measures ANOVA(RMANOVA) and Wilcoxon signed rank tests.

RESULTS

1. Efficacy / Duration between Treatments

The average duration between treatments ranged from 18 to 47 weeks, but there was no statistically significant difference in the duration between treatments.

2. VAS

The average VAS score ranged from 6.0 to 7.2, but there was no statistical difference between the treatments.

3. VOLTAGE

All voltages increased at between one or two of the first four treatments, but then the voltages administered remained statistically constant. • L3 Voltage

There was a statistically significant increase in L3 voltage used between the 2nd and 3rd RFA treatments (p< 0.001), but the average L3 voltage administered remained statistically stable beyond the 3rd treatment.

• L4 Voltage

There was a statistically significant increase (+0.069) in L4 voltage used between the 2nd and 3rd RFA treatments (p=0.020), and between the 3rd and 4th (+0.17, p=0.008), but beyond the 4th treatment the average L4 voltage administered remained statistically stable.

• L5 Voltage

There was a statistically significant increase (+0.12) in L5 voltage used between the 1st and 2nd (p=0.007), and between the 2nd and 3rd (+0.06, p=0.042) RFA treatments, but the average L5 voltage administered remained statistically stable beyond the 3rd treatment.

4. Age Associations

It appears that the voltage required may go up with increasing age (p=0.020) for L4 at baseline.

CONCLUSION

Our results show that a higher sensory stimulation is required for repeat RFA but the length of efficacy stayed the same. The possible reason for this observation is due to scarring or regeneration of the nerve in a more diffuse path.

REFERENCES

1. Pain Pract. 2002 Mar;2 (1):47-52

Radiofrequency Neurolysis for Facet Arthropathy: A Retrospective Case Series and Review of the Literature

Royal MA,Bhakta B,Gunyea B et al

2. Spine. 2004 Nov 1;29(21):2471-3.

Effectiveness of repeated radiofrequency neurotomy for chronic lumbar zygapophysial joint pain.

Dreyfuss P,Halbrook B, Pauza K et al

[Figure 1]

[Figure 2]

[Figure 3] A118

INTRAVASCULAR CONTRAST FOR REGIONAL ANESTHESIA J. Cohen, D. Tseng, X. Ma, A. Gray Anesthesia and Perioperative Care, University of California, A, Anesthesia and Perioperative Care, Anesthesia and Perioperative Care, University of California Los Angeles, San Francisco, CA, USA Ultrasound guidance for regional anesthesia has potential to reduce local anesthetic volumes, chance of vascular puncture, and provide rapid recognition of intravascular injection. Despite these potential advantages, the overall effectiveness of ultrasound guidance in reducing the frequency of local anesthetic systemic toxicity remains to be determined and reports of these adverse events continue to occur.

In vitro experiments were performed to ascertain which clinical factors are most important to visibility of simulated intravascular injections. A number of clinical factors were examined including flow rate; mode of imaging; needle length and gauge; glucose concentration, dissolved gas content and temperature of the injectate. Experimental injections were performed in a water bath using clinically degassed solutions (no visible air) and indices of injection conspicuity were measured. A syringe injection pump was used to simulate clinical injections under controlled conditions. While many parameters may influence recognition of the injection, steady-state injection area (mm**2) and the average pixel intensity within this selected area (PI) were measured.

As expected, injection contrast was flow rate dependent, with higher levels of contrast observed at higher flow rates. For a given flow rate and gauge, longer needles generated more injection contrast presumably because of the higher driving pressure. Similarly, small internal diameter needles of the same length generated more injection contrast at low flow rates. At the highest flow rates tested the injection contrast was at a maximum value and was not enhanced further with use of smaller internal diameter needles. Within a well-adjusted range of image quality controls, B-mode imaging was the least sensitive for detection of injection contrast among those imaging modalities tested. However, we elected to perform most studies with B-mode because this is the predominant mode for performing regional blocks with ultrasound. The main effect of glucose is to stabilize the contrast (persistence of the signal after injection). This is consistent with the use of glucose as an intravenous contrast adjunct to enhance signals from bolus injections imaged distant from the site of injection. Alkalinization of local anesthetic solutions with sodium bicarbonate was remarkably ineffective at enhancing injection contrast despite significant levels of carbon dioxide gas. For lipid soluble local anesthetics echo enhancement only occurred at levels expected to additionally cause precipitation of the free base. These effects are consistent with solid particles forming the genesis of the observed echo signal and not evolution of carbon dioxide gas, which may rapidly redissolve or remain dissolved in aqueous solution during injection.

A clinical study is underway to establish the importance of thermal gradients in determining the injection contrast. The underlying hypothesis is that the thermal gradient and rapid mixing in the blood stream causes dissolved gases (principally oxygen, nitrogen and water vapor) to evolve out of solution. This occurs without significant effects on extravascular contrast because of relatively slow thermal equilibration that occurs after soft tissue injection.

[Graph 1]

[Graph 2]

[Graph 3] A119

INTERSCALENE BLOCK FOR ANALGESIA AFTER OPEN REDUCTION AND INTERNAL FIXATION OF MEDIAL AND MID-CLAVICULAR FRACTURES J.-L. Horn, B.F.S. Allen, S.S. Shah Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA Though surgical repair of clavicle fracture may hasten recovery and minimize pain, immediate post-surgical pain is significant - often requiring overnight hospitalization for pain control. Interscalene brachial plexus blockade (ISB) provides excellent postoperative analgesia for distal clavicle repair, but the literature is not clear as to the innervation of the medial clavicle. Traditionally, it is assumed that the mid and medial thirds of the clavicle are innervated by the supraclavicular nerve emerging from superficial cervical plexus (C3 and C4). This study both reviews literature on clavicular innervation and assesses the efficacy of ISB placed for postoperative pain control after surgical repair of mid and medial clavicle fractures.

First, we reviewed anatomy of the clavicle innervations in classic atlases; we then performed a Medline search on clavicle fracture and regional anesthesia. Third, we reviewed the charts of patients who underwent ORIF of medial or mid clavicle and received an ISB. The data was retrieved from our electronic medical record. We recorded the demographic data as well as postoperative pain score and side effects. We also confirmed surgical location and repair by reviewing patient X-rays.

Descriptions of clavicular innervation found in the literature are summarized in Table 1. Both the brachial plexus and cervical plexus are identified as giving branches to the medial and mid clavicle, consisting of several nerves.

We identified 9 subjects 16-64 years old (Table 2) who were given an ISB with ultrasound guidance for surgical repair of the clavicle. Eight received a block prior to surgery and none experienced surgical pain greater than 3/10 on the Visual Analog Scale at any time in the recovery room. Two patients consented to have an IS block only if a superficial cervical plexus block failed to cover their pain: one patient received his blocks preoperatively, the other patient deferred block until the postoperative period. In both patients the superficial cervical plexus block failed to provide any analgesia whereas the ISB abolished their pain completely. Two further patients underwent superficial cervical plexus block along with ISB.

Interscalene blocks were performed using 18 to 30 mL 0.5% ropivacaine in 8 patients and 0.5% bupivacaine in 1 patient. When a superficial cervical plexus block was performed, 5 to 10 ml of 0.5% ropivacaine was used. No patient experienced side effects or complication due to regional anesthesia.

Although the literature describing the innervation of the mid or medial clavicle cites nerves emerging from C3-C6 roots, an isolated ISB appears to be a valid option to control postoperative pain. Our experience shows, superficial cervical plexus block is neither necessary nor sufficient for mid or medial clavicle pain. Of the 9 patients, only 4 received a superficial cervical plexus block, yet none had pain postoperatively. In contrast, interscalene blockade appears ideal, reducing pain in every patient. Our results indicate that the sensory innervation to the medial and mid clavicle by roots C3 and C4 is insignificant (contrary to reference texts), though there may be some spillover from ISB to the superficial cervical plexus.

[Table 1]

[Table 2] A120

IV ACETAMINOPHEN USE IN PATIENTS WHO UNDERWENT HIP OF KNEW SURGERY: A SYSTEMATIC CHART REVIEW T. Oursbourn, T. Oursbourn A, Pharmacy, Grace Medical Center, Lubbock, TX, USA IV Acetaminophen Use in Patients who Underwent Hip or Knee Surgery: A Systematic Chart Review

IV acetaminophen was approved for use in pain management or reduction of fever in November of 2010 by the US FDA. IV acetaminophen administered over 24 hours has been shown in a repeated-dose, randomized, double-blind, placebo-controlled study in patients with moderate to severe pain after major orthopedic surgery to provide rapid and effective analgesia.1-2 Grace Medical Center started using IV acetaminophen as soon as it became available in the US. A chart review was conducted to compare the outcomes of patients prior to and post introduction of IV acetaminophen.

Methods:

Patients who underwent hip or knee surgery at Grace Medical Center pre- (N=138) and post- (N=132) IV acetaminophen were included. The time period for the patients not treated with IV acetaminophen included Jan 1, 2010 to Jan 17, 2011 and for those treated with IV acetaminophen included Jan 19, 2011 to Oct 31, 2011. Charts were reviewed sequentially. Written informed consent was obtained from all patients. All applicable charts were reviewed for the following information: demographic, time spent in the PACU, narcotic usage (converted to morphine equivalents), and total number of days of narcotic usage. Descriptive statistics were summarized and compared by treatment groups. All statistical tests were two- sided and conducted at the 0.05 level of significance.

Results: A total of 270 patient charts were reviewed (138 pre-IV acetaminophen availability [51 and 87 with hip and knee surgery, respectively] and 132 post-IV acetaminophen availability [39 and 93 with hip and knee surgery, respectively). The groups were well matched in terms of age (mean 68.3 vs. 68.3 years), sex (36.2% vs. 37.1% male) and race (81.9% vs. 86.4% white) between the pre-IV acetaminophen and post-IV acetaminophen groups, respectively. The results of the chart review are contained within Table 1.

The charts were also reviewed regarding the timing of the administration of the first dose of IV acetaminophen (N=130, data not available for 2 patients). Patients could receive their first dose of IV acetaminophen during pre-op (N=55), intra-op (N=51) or post-op (N=24). Using a liner model with timing and surgery type as independent variables, there were no statistically significant differences in terms of total morphine equivalents (p=0.082), total narcotic days (p=0.637) or time spent in the PACU (p=0.993) based upon timing of the first dose.

Discussion: While the administration of IV acetaminophen did not impact the number of minutes spent in the PACU, it did have a statistically significant impact on the morphine equivalents that patients received and the total number of days that narcotics were used.

References: 1. Sinatra RS, Jahr JS, Reynolds L, et al. Pain Pract. Oct 19 2011;DOI 10.1111/j.1533- 2500.2011.00514.x. 2. Sinatra RS, Jahr JS, Reynolds LW, et al. Anesthesiology. Apr 2005;102(4):822-831.

A121

POPLITEAL BLOCK AT THE SITE OF SCIATIC NERVE BIFURCATION THROUGH A COMMON NERVE SHEATH. A RANDOMIZED, DOUBLE-BLIND STUDY W. Patrick, F.W. Abdallah, C. Tse, V. Chan, A. Perlas Department of Anesthesia and Pain Management, Toronto Western Hospital, Department of Anesthesia and Pain Management, Toronto, Toronto, ON, Canada Introduction: Existing approaches for ultrasound-guided sciatic nerve block include blockade proximal to or distal to sciatic nerve bifurcation. A distal approach targeting both the common peroneal (CPN) and tibial nerves (TN) separately has been associated with a faster onset time than blockade proximal to the bifurcation. 1 A subepineureal injection has also been proposed, but it remains controversial due to the potential for nerve injury.2 In this prospective, randomized and double-blind study we compare the efficacy and onset time of a single injection at the site of bifurcation, within the common nerve sheath3 but outside the epineurium of both terminal nerves to a blockade distal to nerve bifurcation. Methods: Patients scheduled to undergo elective foot or ankle surgery are randomly assigned to either blockade 3 cm distal to the site of bifurcation as identified with ultrasound (group D) or blockade at the site of bifurcation within the common nerve sheath but outside the epineurium of each terminal nerve (group B). For group D the CPN and TN are blocked separately with 15ml of local anesthetic solution (50:50 mix of lidocaine 2% with 1:200,000 epinephrine and bupivacaine 0.5%) injected circumferentially around each nerve. For group B, blockade is performed at the site of sciatic nerve bifurcation with an out-of-plane needle approach. The needle is inserted to lie between the two terminal branches, within the common nerve sheath, but outside the epineurium of each nerve. A single injection of 30 mL of the standardized study solution is injected in this location. Results: We present an interim analysis of 36 patients (for a projected 88 subjects, Group D=22, group B=14). To this point, a single injection within the common nerve sheath at the site of bifurcation had a similar onset time for both sensory and motor blocks (22±11min and 22±15min) than a distal separate blockade (19 ± 10 min and 19 ± 9min, p=0.49 and 0.64 respectively). Block performance time was similar (8.7±3.1 min vs 8.5±3.4 min, p=0.84) with a trend of patients in the distal group requiring more than one skin puncture site (32% vs. 21%, Z-score 0.68, p=0.50). There were no complications reported immediately or on post-operative day 7 follow-up. Conclusion: Preliminary data from this ongoing clinical study suggest that a single injection of local anesthetic at the site of sciatic nerve bifurcation in the popliteal fossa, within the common nerve sheath but outside the epineurium of each terminal nerve provides a fast onset time, similar to a distal injection of each terminal nerve. This approach to sciatic nerve blockade at the popliteal fossa is technically simple requiring a single needle entry site in most patients, while preserving nerve integrity.

References:

1.Prasad A, Perlas A, Ramlogan R, Brull R, Chan V. Reg Anesth Pain Med 2010;35:267-271.

2. Tran de QH, Dugani S, Pham K, Al-Shaafi A, Finlayson RJ. Reg Anesth Pain Med 2011;36:548-52.

3. Vloka JD, Hadzic A. Anesth Analg 2001; 92(1):215-7

A122

DEVELOPMENT OF ENHANCED, QUANTITATIVE SONO-ELASTOGRAPHY FOR REGIONAL ANAESTHESIA S. Munirama, G. McLeod, A. Schwab, S. Cohcran, G. Corner Anaesthetics, Institute of Academic Anaesthesia, Medical Physics, University of Dundee, Institute for Medical Science and Technology, Department of Anaesthetics, Ninewells Hospital and Medical School, Dundee, UK Despite the widespread adoption of ultrasound and needles technology, and proliferation of ultrasound guided regional anaesthesia (UGRA) training, no evidence yet suggests any reduction in the incidence of intraneural injection during peripheral nerve block1. Reports of nerve damage during UGRA2 and inadvertent intraneural injection using post block video analysis3 suggest that B-Mode visibility of nerves and surrounding tissue is not sufficient to prevent nerve trauma. Moreover, hydrolocation test doses of 0.5 to 1ml are inappropriate because such small volumes may still cause damage if injected into a nerve fascicle.The limitations of current practice suggest a need to develop new translational technologies in order to measure different tissue properties, and in doing so, differentiate between intraneural and extraneural anatomy using the smallest possible volume of injectate, and characterise spread of local anaesthetic.

Sonoelastography is an ultrasound based technique which measures the displacement of radio frequency (RF) lines before and after probe compression. Compression or strain elastography is used to diagnose liver and breast tumours4, and conceptually may be regarded as a digital form of palpation. Application of sonoelastography to regional anaesthesia in Thiel embalmed human cadavers and patients has shown ready identification of tissue strain5, but still remains a surrogate measure of local anaesthetic spread. Therefore, the primary objective of this study was to develop an enhanced form of sonoelastography in order to quantify the visibility of injection and define the threshold for visibility for interscalene, median and femoral block in the Thiel embalmed human cadaver.

A Zonare z.one scan engine and proprietary elastography algorithm were used to reconstruct images. MATLAB 7.9 software with Mathworks Image Acquisition and Image Processing Toolbox was installed. An adaptive noise-reduction filter and a two dimensional median filter were applied. Two measurements were made: first, the area in pixels of the enhanced elastography image, and second, mean pixel intensity within a grayscale 25 by 25 pixel square, to capture low intensity spread. Images were visualised as a B-Mode, elastography, enhanced elastography and enhanced elastography overlaid with B-Mode, and visibility as the Hydrolocation Index (H) for each frame.

After obtaining Anatomy ethics permission from the University of Dundee we performed interscalene, femoral, and median nerve-blocks on 30 Thiel embalmed human cadavers using volumes of 0.25, 0.5 and 1ml embalming fluid. The study conformed to the Anatomy Act 2006 (Scotland). The results are shown in Fig 1. Maximum median (IQR) H increased with increasing volume but not between blocks. The threshold for visibility was < H 0.4. Only two injections receiving 0.25ml were not visible. An example of enhanced elastography with 1ml injectate during interscalene block is shown in Fig 2.

In conclusion, we have developed a quantitative measure of strain elastography using MATLAB which can visualise tissue strain in 94% of 0.25ml injections. We intend to apply this technology in real time to patients and develop a diagnostic tool. Moreover, such sensitivity means it is possible to see if the local anaesthetic spreads in the wrong direction and reposition the needle accordingly.

References

1. Neal JM, Wedel DJ. Ultrasound guidance and peripheral nerve injury: is our vision as sharp as we think it is? Reg Anesth Pain Med 2010;35(4):335-7.

2. Cohen JM, Gray AT. Functional deficits after intraneural injection during interscalene block. Reg Anesth Pain Med 2010;35(4):397-9.

3. Liu SS, YaDeau JT, Shaw PM, Wilfred S, Shetty T, Gordon M. Incidence of unintentional intraneural injection and postoperative neurological complications with ultrasound-guided interscalene and supraclavicular nerve blocks. Anaesthesia 2011;66(3):168-74.

4. Evans A, Whelehan P, Thomson K, McLean D, Brauer K, Purdie C, et al. Quantitative shear wave ultrasound elastography: initial experience in solid breast masses. Breast Cancer Res 2010;12(6):R104.

5. Munirama S, Satapathy A, Corner GA, Cochran S, McLeod GA. Translation of sonoelastography from Thiel cadaver to patients for peripheral nerve blocks. Anaesthesia 2011;66(10):962-63.

[Figure 1]

[Figure 2] A123

PRELIMINARY ASSESSMENT OF AN IMMERSIVE REGIONAL ANESTHESIA WORKSHOP FOR ANESTHESIOLOGISTS IN PRACTICE T.E. Kim, T.K. Harrison, E.R. Mariano, A. Kou, S.K. Howard Veterans Affairs Palo Alto Health Care System, Stanford University, Palo Alto, 4Anesthesiology and Perioperative Care Service, Veterans Affairs Palo Alto Health Care System, Stanford University Medical Center, Palo Alto, CA, USA Background: Since the introduction of ultrasound (US) technology to regional anesthesia (RA), especially peripheral nerve blocks (PNB), various teaching methods have been developed, some of which have been studied in the setting of resident trainees. Similar programs, such as continuing education workshops, have been applied to practicing anesthesiologists, the majority of whom have not received US instruction as part of their residency training. However, the efficacy of teaching methods in this population has yet to be determined. Furthermore, the additional learning and system-based resources that are required by practicing anesthesiologists to begin performing these new techniques following workshops are currently unknown. Methods: During a 2 month period, 12 anesthesiologists participated in a one-day RA workshop (3 participants per day) that included didactic lectures, observation of continuous PNB on actual patients, US scanning of human models, and performance of US-guided continuous PNB in a hybrid simulator (mannequin/porcine meat model) under realistic clinical conditions within an immersive learning center. Participants were asked to complete pre-course surveys and post-course surveys immediately following and 3-6 months after the workshop to assess changes in PNB practice, perceived effectiveness of US teaching methods using a Likert scale, and resources most likely to be used after the course to learn more about US-guided PNB. For the 3-6 month follow-up, participants were contacted initially by email with non-responders receiving a follow-up email or telephone survey using the same instrument. Results: All 12 participants completed pre-course and immediate post-course surveys. All participants gave enjoyment and learning the highest possible rating. Three to six months after the course, 8 post-course surveys were collected by email (75%) or via telephone (25%). After participation in the course, there were no statistically-significant changes in the average percentage of clinical practice devoted to PNB (p=0.36) and average number of PNB performed (p>0.99). There were no changes in the perceived effectiveness of US teaching methods before vs. after the workshop. Participants planned to use the following for continued learning of US-guided PNB: teaching by colleagues, observation of PNB on patients, self-teaching, and online tutorials (Figure 1).

Conclusions: In this preliminary assessment, participation in a one-day immersive workshop promotes enthusiasm and the pursuit of further learning in US-guided RA but does not lead to significant short-term increases in PNB performance. After this workshop, there is a consistent trend in the preference of future learning modalities. These findings suggest that there continue to be obstacles in acquiring skills requisite to perform US-guided PNB, and further studies are needed to delineate specific barriers to changing practice.

References: 1) Reg Anesth Pain Med. 2004 Nov-Dec;29(6):544-8. 2) Reg Anesth Pain Med. 2010 Mar-Apr;35(2):224-6.

[Figure 1] A124

UTILIZATION OF HIGHER LEVELS OF CARE AMONG TOTAL JOINT ARTHROPLASTY RECIPIENTS D. Yoo, O. Stundner, X. Sun, Y.-L. Chiu, M. Nurok, S.G. Memtsoudis Department of Anesthesiology and Intensive Care, Salzburg University Hospital, Salzburg, Austria, Public Health, Weill Cornell Medical College, Public Health, New York, Department of Anesthesiology, Hospital for Special Surgery, New York, NY, USA Background: The number of hip and knee arthroplasties performed in the US is steadily increasing. This burden on the health care system has been accompanied by increases in the medical acuity of patients presenting for this popular procedure. Despite this trend, there is a paucity of data evaluating the utilization of higher levels of care, including intensive care, telemetry and step down unit services. This information is important to help clinicians and administrators allocate appropriate resources.

Materials and Methods: Data collected by Premier INC. from approximately 350 hospitals between 2006 and 2010 was accessed. Patients who underwent primary hip or knee arthroplasty (THA, TKA) were identified and included in our analysis. Patient and health care system related demographics for patients requiring higher levels of care, including intensive care, telemetry and step down unit services were compared to those who did not require such services. The prevalence of comorbidities and postoperative complications were compared between groups. Differences in outcomes such as mortality, disposition status and hospital charges were analyzed. Finally, a regression analysis was performed to identify risk factors for the need of higher level of care.

Results: We identified a total of N=528,495 entries for patients who underwent primary THA (n=172,467, 33%) and TKA (n=356,028, 67%). Of those, approximately 1 in 10 required higher levels of care (2.9% step down unit, 3.3% telemetry, and 3% intensive care services). Patients requiring higher levels of care were on average 2 years older, P< 0.001), more frequently male (42% vs. 38%, P< 0.001), and had a higher average comorbidity burden (average Deyo Index 1.2 vs. 0.8, P< 0.001, compared to their counterparts not requiring such care. Higher levels of care were utilized more frequently in medium sized hospitals, in urban settings and amongst teaching institutions compared to large, rural and non-teaching facilities.

Patients requiring higher levels of care were more frequently affected by major complications. The average length of hospital stay was also higher (4.8 vs. 3.4 days, P< 0.001)) among this patient group. Higher level of care recipients had higher mortality rates (0.8% and 0.04%, P< 0.001) and were less likely to be discharged home (54% vs. 64%, P< 0.001) than other patients.

Average hospital charges were approximately 32% higher among patients requiring higher levels of care (P< 0.001).

The risk factors with the highest odds for the requirement for higher levels of care were increasing age, comorbidity burden and postoperative complications.

Conclusion: One in ten patients undergoing total joint arthroplasty requires higher levels of care. Given the large number of procedures performed in the US per year, perioperative physicians need to familiarize themselves with particularities of this patient population. Clinicians and administrators need to be aware of the significant clinical and economic impact this population represents and allocate resources accordingly.

A125

THE USE OF CADAVER MODELS FOR LEARNING AIRWAY SONOANATOMY AND REGIONAL TECHNIQUES B. Tsui, V. Ip, A. Walji Department of Anesthesia and Pain Medicine, University of Alberta Hospital, Division of Anatomy, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada Purpose:

The strategy of using human cadaveric models for teaching ultrasound-guided peripheral nerve blocks has been described for both the trunk and the upper and lower extremities. This study highlights the parallels between cadaveric and live imaging as is relevant to ultrasound (US) scanning of the airway and the related regional blocks. The aim of the study is to determine if there is great variation of the airway sonoanatomy between cadaver and live models, hence, whether the cadaver model is a viable training tool for understanding the sonoanatomy and for practising ultrasound-guided superior laryngeal nerve blocks, and transtracheal injections. Methods: Cadavers were in the legal custody of the Division of Anatomy of the authors' institution; permission for their use was obtained from the Division of Anatomy and is in compliance with the institutional ethical standards for the use of human material in medical education and research. Ethics approval was obtained from the local Institutional Research Ethics Board for US scanning on the volunteers (two of the authors). Ultrasound images using a portable machine (MicroMaxx, SonoSite Inc., Bothel, WA, USA; HFL38 13-6 MHz linear array probe) were obtained from scanning the neck of one embalmed male and one embalmed female adult cadaver. The areas of interest were between the hyoid bone and the second tracheal ring since this region is the most relevant for regional anesthesia of the airway. The images were compared with those taken from one live male and one live female adult subject. The ultrasound airway images of the cadaver were verified by real time ultrasound guided needle puncture onto the cartilaginous or bony structures. Fibreoptic bronchoscopy was also performed to monitor needle puncture into the trachea during transtracheal injections in cadavers.Results:

The sonoanatomy of the airway is strikingly similar between cadaveric and live models. The hyoid bone, an important landmark for the superior laryngeal nerve, can be easily identified under US imaging. The upper and lower borders of the thyoid cartilage and cricoid cartilage can also be easily appreciated for transtracheal injection through the cricothyroid membrane.Conclusion:

Cadavers may provide viable training options for practising ultrasound imaging and real-time ultrasound needle guidance for superior laryngeal nerve block and transtracheal injection to anesthetize the airway mucosa. Training can be performed in a stress-free, pre-clinical environment without time constraints or the potential for patient discomfort. The limitation of using cadaver models is that it removes the problems faced during clinical scenarios such as movement during respiration, patient anxiety, discomfort, and time constraints.

A126

POST-DURAL PUNCTURE HEADACHE: A COMPARISON BETWEEN MEDIAN AND PARAMEDIAN APPROACHES IN ORTHOPEDIC PATIENTS F. Mosaffa, K. Karimi, F. Madadi, H. Khoshnevis, L.D. Besheli, A. Eajazi Anesthesiology & Pain Management, Akhtar Orthopaedic Hospital, Shahid Beheshti University of Medicine, Tehran, Iran Background: Post-dural puncture headache (PDPH) is an iatrogenic complication of spinal anesthesia. Reported risk factors for PDPH include sex, age, pregnancy, needle tip shape and size, bevel orientation, approach and others. Little is known regarding the effect of different approaches on the incidence of PDPH.

Objectives: In this study we aimed to compare the incidence of PDPH in the case of median and paramedian approaches in patients undergoing spinal anesthesia for orthopedic operations.

Patients and methods: Patients scheduled for orthopedic surgery under spinal anesthesia between 2007 and 2008 were studied in a double-blinded randomized controlled trial. The patients were randomized to receive spinal anesthesia by either a median (n = 75) or paramedian (n = 75) approach through a 25-gauge Crawford needle. No premedication was given, and all patients received 500 mL of normal saline intravenously and 4 mL of 0.5% isobaric Marcaine 30 minutes prior to surgery in both approaches.

Results: Fifteen patients (10%) developed PDPH. There was no significant difference in the incidence of PDPH in both groups, with 7 (9.3%) patients in the median approach group versus 8 (10.7%) in the paramedian approach group developing typical PDPH (P = 0.875). However, a significant difference in PDPH incidence (P = 0.041) was observed between females (9; 16.7%) and males (6; 6.3%).

Conclusions: There is no difference between median and paramedian approaches with respect to PDPH incidence; the paramedian approach is therefore recommended, especially for older patients with degenerative changes in the spine and intervertebral spaces and those who cannot take the proper position. Moreover, the rate of PDPH was found to be significantly higher in females than in males..

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THE ASSOCIATION OF GENDER AND BODY MASS INDEX (BMI) WITH POSTOPERATIVE PAIN SCORES WHEN UNDERGOING ANKLE FRACTURE SURGERY UNDER GENERAL ANESTHESIA S. Grodofsky, W.J. Levy Anesthesia and Critical Care, University of Pennsylvania, Philadelphia, IA, USA Introduction: In the absence of regional anesthesia, using intraoperative opiates to provide adequate and safe postoperative analgesia proves challenging due to its highly variable pharmacodynamics and side effect profile. Rather than taking a weight based approach to dosing, accounting for certain patient characteristics may refine an analgesic plan. Various studies have identified that women both report greater pain scores to nociceptive stimuli and have a higher incidence of chronic pain. In addition, studies have shown a greater incidence of chronic pain in obese patients. This study attempts to retrospectively evaluate if gender and/or body mass index predict reported postoperative pain scores after undergoing a similar surgical procedure- open reduction and internal fixation (ORIF) of an ankle fracture. The relevance will be to assess whether two easily identifiable patient characteristics should influence opiate dosing.Methods: The Hospital of the University of Pennsylvania anesthesia electronic medical record system was queried to identify all patients undergoing general anesthesia without regional for an ORIF between 2006-2011 receiving morphine only analgesia (175 patients). Exclusion criteria included: undergoing a repeat ORIF, receiving multi-modal analgesia, the preoperative presence of chronic pain requiring high dose opiate therapy and receiving a dose of Morphine < 0.1 mg/kg or >0.3mg/kg. 110 patients survived cut-off for analysis. The dependent variable consisted of the patient's post-anesthesia care unit(PACU) Verbal Numerical Pain Scores, rated on a subjective 0 to 10 point scale (0=no pain, 10 =worst pain in life) upon first arrival and 30 minutes later. Results: The mean results and distribution of minimal (0-3), moderate (4-7) and severe (8-10) pain are recorded in the attached table. There are no statistically significant differences when comparing the mean pain scores by gender or BMI. Using the Fisher's exact test, there is a statistically different distribution in pain severity when comparing first reported pain score in patients with a BMI >30 and < 30 (P=.01). There was no significant difference in age, surgical time, weight based morphine dose or ASA status when making group comparisons.Discussion

This study retrospectively analyzes a uniform injury, surgical procedure and anesthetic approach to identify if gender or BMI influence immediate reported postoperative pain scores. According to the data, there is no clear pattern that should influence intraoperative opiate dosing. The study does suggest that patients with a higher BMI are more likely to report the extremes of pain scores. The study limitations include its single institution retrospective design, reliance on subjective measures and short follow up period.

[Figure 1] A128

TRANSIENT PARTIAL BRACHIAL PLEXUS BLOCK COMPLICATING ULTRASOUND-GUIDED ACCESSORY NERVE BLOCK PERFORMED FOR DIAGNOSIS AND TREATMENT OF MAYOFASCIAL PAIN IN THE TRAPEZIUS MUSCLE: A CASE SERIES F.W. Abdallah, A.V. Morgan Anesthesia, Sunnybrook and Women's College HSC, Toronto, ON, Canada Background

Myofascial pain syndrome (MPS) is a musculoskeletal non-inflammatory pain refractory to pharmacological treatment frequently affecting the trapezius muscle. Neuropathy of accessory nerve innervating the trapezius and involuntary trapezius contractions are proposed explanations to this pain. Trapezius motor block via trigger point injection serves as a diagnostic and therapeutic block that relaxes painful contractions and reduces pain transmission. Recently, an ultrasound-guided (USG) accessory nerve block below the posterior edge of the sternocleidomastoid muscle (SCM) has been described.1 Our case series examines potential complications of this technique. Methods

Twenty two patients diagnosed with MPS in the trapezius following work up that excluded other causes were consented to accessory nerve block. The posterior border of the SCM was scanned to localize nerve, first at the cricoid level and then in a cranial-caudal fashion when nerve was not found. Nerve stimulation eliciting trapezius twitch confirmed needle position and excluded phrenic nerve. Unilateral USG perineural injection targeting circumferential spread was performed using 3 mL of 0.25% bupivacaine mixed with epinephrine 1:200,000. Patients were assessed for pain relief and newly onset sensory or motor deficits at 10 and 20 minutes after injection. Results

Total relief occurred in 14 patients (63.6%), significant pain relief (≥ 20 mm reduction in VAS) in 5 (22.7%), minor pain relief (< 20 mm reduction in VAS) in 2 (9%), and 1 (4.5%) reported no change. An undesirable partial brachial plexus block diagnosed by numbness and/or weakness over C5, C6, or C7 dermatomal distribution was observed in 6 patients (27.3%). Discussion

The relatively high incidence of partial brachial plexus block with a small volume of local anesthetics exceeds the 1.6 %,2 2.7%,3 and 3.8%4 rates reported to complicate superficial cervical plexus block when volumes ≥ 10 mL are injected. This, together with the fact that brachial plexus is a deeper structure shielded by investing and deep cervical (prevertebral) fascial layers, render anatomic proximity an unlikely explanation for the observed partial block. However, recent anatomic evidence suggests absence of investing fascia between SCM and trapezius muscles,5, 6 extensive channels between connective tissue deep to the SCM and the subcutaneous tissue,7 as well as “pores” in the prevertebral fascia along nerve trajectories8 may explain why deep and superficial spaces of the neck act as a single space.9 Finally, the confinement of spread between carotid and SCM sheaths anteriorly and trapezius sheath posteriorly amplifies the volume spread of injectate by a factor of two favoring a cranio-caudal spread along C1-C7 roots.10 This theory has also been proposed to explain the lack of analgesic difference between superficial and deep2, 6, 11 as well as superficial and intermediate cervical plexus blocks performed for carotid endarterectomy.12 Future research should investigate alternative accessory nerve block techniques to minimize incidence of undesired nerve block.

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CONTINUOUS PARAVERTEBRAL NERVE BLOCK AS AN ALTERNATIVE TO EPIDURAL ANALGESIA FOR NUSS PROCEDURE D.M. Hall-Burton, M. Visoiu Anesthesiology, University of Pittsburgh Medical Center, Pittburgh, Anesthesiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA Introduction: Pectus excavatum repair with a Nuss procedure is a common pediatric surgical procedure. Pain following the Nuss Procedure is severe and difficult to control. The use of a thoracic epidural catheter has been advocated as a superior method of controlling postoperative pain following this surgery. Thoracic epidurals, however, are not without risk. In a recent review of 1,215 Nuss Procedures, two cases of lower extremity paralysis were reported in patients receiving thoracic epidurals. We report the use of bilateral paravertebral nerve block (PVNB) catheters in three patients after the Nuss procedure.

Methods: The medical records of six patients with a history of pectus excavatum and repair via a Nuss procedure were reviewed. All patients were over 14 yrs of age, weighed more than 50 kg and were ASA status 1 or 2. Three patients had epidural catheters and three patients had PVNB catheters placed for postoperative analgesia. Patients and their families were offered a choice of PVNB catheters, thoracic epidural catheters or patient controlled analgesia for postoperative analgesia. All blocks were placed under conscious sedation preoperatively. PVNB's were placed with an 18g 8cm tuouhy needle at the level of the T6 transverse process. A classic approach was used with the needle directed caudally below the transverse process and the space identified with loss of resistance. A 20g catheter was inserted 2-3 cm beyond the tip and the catheter secured. Each catheter was bolused with 15 ml of ropivicaine 0.5% upon insertion and ropivicaine 0.2% infusions started at 7ml/hr. Epidural catheters were placed midline in the T5-T6 interspace using an 18g 8cm tuohy needle. The epidural space was identified with loss of resistance and a 20g catheter inserted 2-3 cm beyond the tip and secured. The catheters were bolused with ropivicaine and infusions stated at 7ml/hr. All catheters were continued for 2-3 days. Intraoperative opiates were not controlled were given per the usual practice of the attending anesthesiologist. All patients were extubated postoperatively and transferred to the PACU. In addition to the nerve blocks, a standardized multimodal pain regimen was implemented. Patients were followed daily by the Acute Perioperative Pain Team.

Results: Patient data is reported in attached figures. No differences in pain scores, opioid consumption or time to first opioid were statistically significant.

Discussion: Our institution offers patients and their families a choice between PVNB and thoracic epidural analgesia for thoracic surgery. The use of PVNB for controlling postoperative pain in thoracotomy patients has been shown to have equal efficacy to epidural nerve blocks with a better side-effect profile and a lower incidence of pulmonary complications. In addition, no reports of paralysis have been attributed to the placement of PVNBs. In this series, a trend towards equivalent postoperative analgesia as evidenced by VAS and opioid consumptions over 48 hours was shown. Additional studies are needed to directly compare PVNB, thoracic epidural nerve blocks, and patient controlled analgesia for the Nuss procedure in pediatric patients.

Conclusions: PVNB for the Nuss procedure in pediatric patients provides adequate postoperative analgesia.

[Graph 2]

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IMMEDIATE AND TANGIBLE RETURNS FROM ELECTRONIC MEDICAL RECORDS ON AN ACUTE PAIN SERVICE K.S. Mon, G. Kong, J. Brookman, E. Freck, S.C. Swanson, M. Hanna Anesthesia and Critical Care Medicine, Johns Hopkins University, Anesthesia and Critical Care Medicine, johns Hopkins University, Baltimore, MD, USA Introduction:

There is a diverse literature on electronic medical records (EMR) showing many important quality- and efficiency-related benefits: such as patient satisfaction, patient safety and decrease in utilization of care. However, there are large gaps in this body of literature with particular regards to the financial context, such as data on exact monetary cost and gains. This study is an attempt to fill in some of the gaps by reporting on our experiences with professional fee (profee) revenues before and after implementation of an electronic medical record system. Methods:

The Acute Pain Service (APS) at Johns Hopkins Hospital implemented the Citrix ® Sunrise Provider Order Entry (POE) electronic medical record system on November 8, 2010. In this retrospective study, we reviewed all the profee charges billed on behalf of the APS service during the “pre-EMR period” (Nov 8, 2009 to Oct 31, 2010) to the “post-EMR period” (Nov 8, 2010 to Oct 31, 2011). We also analyzed the internal database of daily APS patient census over the corresponding time periods as a basis of comparison for the clinical workload. Results:

Overall, a total charge of $477,161 billed during the paper period, which increased to a total of $666,794 after implementation of POE, which represent a gain of 40%. Actual payments received also saw a corresponding gain, going from $200,407 to $280,053, for a net gain of $79,646 (40%). We also saw noticeable improvements in billing capture rates, particularly with regards to a 67% decrease in number of days without any billing activity (14 during the paper period to 6 during the POE period,) as well as a greater capture of higher level billable care (see table 1.) Discussion:

Despite a large body of evidence on various improvements in quality and efficiency of patient care, physicians' and hospitals' use of EMR is still low and slow to improve. Though not without hardship, a shift to EMR from paper records, while keeping a constant model of staffing and workflow, has resulted in a 40% increase in revenue. There are many possible factors that can attribute to the total bottom line increase, but we believe that much of it can be either directly or indirectly attributed to a better process of billing capture that is brought about by better record keeping. It should be noted that this is an ongoing process. This is but an encouraging first step and a small part of the process for an overall improvement in patient care and clinical efficiency.

Table 1. Distribution of Billing based on CPT codes Paper/Pre-EMR period (Nov 8, 2009 to Oct 31, 2010) vs. Electronic/Post-EMR period (Nov 8, 2010 to Oct 31, 2011)

[Table 1. Distribution of Billing based on CPT cod] A131

THE USE OF ECHOGENIC CATHETERS FOR ASSESSING CATHETER POSITION AFTER ULTRASOUND-GUIDED PLACEMENT OF A CONTINUOUS PERIPHERAL NERVE BLOCK IN CADAVERS R.J. Waclawski, J.W. Heil Anesthesiology, Naval Medical Center San Diego, San Diego, CA, USA The use of peripheral nerve block (PNB) catheters have become common for post-operative analgesia in orthopedics. Ultrasound visibility of the nerves and needles during local anesthetic placement is thought to potentially increase safety and success of the procedure. However, subsequent placement of the PNB catheter in near proximity of the nerve can be challenging even when using ultrasound guidance due to the difficulty of visualizing the catheter, and the potential for the catheter tip to migrate away from the initial point of placement. We present a new echogenic catheter (Teleflex© Prototype, 19 ga antimicrobial) with a stainless steel tip to use ultrasound for confirmation of the position of a PNB catheter tip after placement. We used fresh cadavers as a reasonable simulation of ultrasound imaging compared to live patients. We formally assess the ultrasound visibility of echogenic catheters in fresh cadavers and discuss the potential benefits for continuous peripheral nerve block catheters in regional anesthesia.v

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HUMAN PATIENT SIMULATION FOR TRAINING IN CRISIS MANAGEMENT OF REGIONAL ANESTHESIA COMPLICATIONS P.A. Sloan, Z.U. Hassan, J.S. Grider University of Kentucky, Lexington, Lexington, KY, USA Background: Patient simulation in anesthesia training is becoming more common, especially in the area of crisis management, in which exposure to rare but potentially catastrophic events can be completed in an environment that does not jeopardize patient safety.1 Simulation scenarios of local anesthetic systemic toxicity (LAST) have been reported using a simulated continuous lumbar plexus block2, but there is little in the literature regarding the simulation of other complications of regional anesthesia. Also, the use of combination simulation modalities has not been explored.

Objective: The aim of this pilot study is to create a simulation scenario, including combination simulation modalities, for the training of anesthesia residents in the treatment of complications of regional anesthesia.

Methods: Simulation scenarios were written for CNS toxicity and LAST, as well as pneumothorax as complications of regional anesthesia. The stem (common to each scenario) describes a recently placed continuous supraclavicular catheter as the source of the complication. This allows for simply taping a catheter to the mannequin in the supraclavicular area for realistic simulation. We then combined simulation modalities by adding TTE/TEE clips appropriate for each scenario. This TTE/TEE clip entered the scenario by means of a simulated respondent to the trainee's call for help, suggesting TTE or TEE might help with diagnosis during a prolonged and difficult resuscitation.

Results: The simulations were piloted on faculty from our institution, with promising results, and with the intention to apply the simulations to resident education. The residents would have subsequent debriefings on the complications, and would be surveyed about their confidence in more quickly recognizing and more quickly and accurately treating the complication than they would have been able to do prior to the simulation.

Conclusions: 1) Simulated scenarios of regional anesthetic complications were piloted on faculty from our institution with promising results, and likely good applicability toward resident education. 2) Area for potential improvement: We used clips that had previously been saved to a database of echocardiographic images when the trainee asked for echo to help with diagnosis. An improvement would be to incorporate the HeartWorks simulator currently used at our institution to perform a realtime TTE or TEE which would match the scenario at hand. This would require a particular pathologic process algorithm for the HeartWorks simulator, but would add another level of both realism and teaching opportunity for trainees, who could see the physiologic differences in such things as LAST versus myocardial ischemia or tension pneumothorax.

Reference: 1. Hassan ZU. Sim Healthcare 2008; 3:47-52.

2. Torsher LC. Sim Healthcare 2009; 4:109-113.

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THREE PATIENTS WITH PAINFUL BRACHIAL PLEXUS IMPINGEMENT FOLLOWING PACEMAKER GENERATOR PLACEMENT V.K. Puppala, G.N. Kozlov, M. Razminia, N.N. Knezevic, K.D. Candido Division of Pain Medicine, Loyola University Medical Center, Maywood, Section of Cardiac Electrophysiology, Advocate Illinois Masonic Medical Center, Department of Anesthesiology, Chicago, Department of Anesthesiology, Advocate Illinois Masonic Medical Center, Chicago, IL, USA Introduction: We present three distinct cases of patients who developed upper extremity numbness, tingling, pain, and weakness following pacemaker generator implantation. All three were referred within a four-month time span for diagnostic anesthetic techniques until definitive treatment with generator revision was undertaken. Pain practitioners should be aware of this etiology of brachial plexopathy, which may become more prevalent in decades to come as increasing numbers of patients undergo cardiac device implantation.

CASE DESCRIPTIONS: A 37-year-old woman presented with five years of worsening intermittent left chest, shoulder, and scapular pain radiating into the left upper extremity exacerbated by movement following pacemaker placement for sick sinus syndrome. Exam revealed trapezius tenderness but no focal neurologic deficits. A 63-year-old woman was referred following a sudden onset of intermittent right arm numbness and weakness three months following AICD implantation for congestive heart failure. Exam revealed ipsilateral deltoid and triceps weakness. A 37-year-old man presented with a four year history of progressive numbness of the left upper extremity and sharp pain over the left axilla radiating to the medial forearm, wrist, and fourth and fifth digits exacerbated by shoulder abduction following pacemaker implantation for vasovagal episodes and history of asystole.

Methods: All three patients failed conservative management with NSAID, anticonvulsant, and opioid therapy. Diagnostic ultrasound and fluoroscopic techniques were used to evaluate each patient. Under ultrasound guidance, the axillary artery, vein, and brachial plexus were identified and contrast was administered through a 21G needle into the brachial plexus sheath. 5mL of Omnipaque (Iohexol) 180 injected into the sheath revealed a filling void due to proximal impingement of the sheath by each cardiac device. With abduction of each patient´s upper extremity, each device moved into close proximity of the brachial plexus sheath, likely impinging the plexus. Due to the impingement of the brachial plexus by the pacemaker, regional techniques were deemed to be only temporizing. Each patient was referred back the referring cardiac electrophysiologist for pacemaker generator revision which provided long-term pain relief.

Discussion: Although pain is common following device implantation, the presence of persistent, chronic upper extremity neuropathic pain may indicate impingement of the brachial plexus sheath. Our three cases in a short time span may indicate this complication is more common than previously thought. Cardiac device migration may be caused by range of motion of the upper extremity and is unlikely to resolve with conservative therapy. Image- guided anesthetic techniques may be useful diagnostic measures to elucidate symptom etiology. Durable relief requires definitive treatment with surgical device revision.

[Image 1] A134

MANAGEMENT OF SEVERE HEADACHE IN AWAKE PATIENTS WITH INTRACEREBRAL HEMORRHAGE S. Chamandi, M. Helou, T. Matta Head of pain clinic, ICU department, Notre Dame University Hospital, Byblos, Anesthesia, Chairman of Anesthesia department, Lebanese University, Medical Faculty Anesthesia Department, Notre Dame University Hospital, Beirut, Lebanon Introduction:

Our Intensive Care Unit (ICU) has been treating patients with intra cerebral hemorrhage and subarachnoid hemorrhage for many years. The highest majority of patients with intra cerebral bleed are comatose and require intubation and sedation during their intensive care unit stay, until recovery. Rare are the cases of the patients with diagnosed intra cerebral hemorrhages who were awake, and thus needed no intubation.

Between 2007 and 2010, 12 patients (9 males and 3 females) were admitted into our ICU with a confirmative imaging (MRI) of intracranial hemorrhage. (Intracerebral and subarachnoid hemorrhage). All 12 patient were awake and did not require intubation

The chief complaint of those patients was a severe thunderclap headache that responded poorly to classic antalgics such as acetaminophen and Non Steroid Anti Inflammatory drugs. Opiate, such as morphine, was also used without a significant relief of their headache.

The pain management of the headaches in this group of awake patient with classic antalgics and morphine was not optimal and the need to establish a new pain management method has led us to perform a new supportive therapy for their headache: Nerve Block.

A greater occipital nerve block along with the lesser occipital nerve block, using a nerve stimulator was done bilaterally on all twelve patients using Bupivacine on each side. A dramatic improvement of the headache (according to VAS scale) was noted by the 12 patients after this block.

After having an intra cerebral hemorrhage, patients often experience ongoing severe headaches.

The pain is well documented as a cause of raised intra cranial pressure and it is important to make the pain relief for such patients a priority. (Hickay 1996). Pain is usually unbearable and leads in many cases to agitation. [1]

This pain (headache) with or without agitation must be avoided because it can aggravate the intra cerebral pressure elevation through straining (increasing thoracic, jugular venous, and systemic blood pressure), it can increase the cerebral metabolic rate of oxygen, and also it may cause uncontrolled hyper/hypo-ventilation[1].

During an ICP spike, pain management of the headache may be all that is necessary to control the intra cranial pressure.

Analgesia is a must to prevent this viscous circle of pain, agitation, increased ICP and increased clinical deterioration (re-bleeding); the risk of re-bleeding is 4% on the first day, and increases by 2% per day to reach 30% in the first month [3].

Effect of acetaminophen:

Treatment with acetaminophen:

Fever is common after SAH and is found in at least one third of patients [2], it is a neurogenic type of fever and treatment with acetaminophen may be needed for hyperthermia. Its antalgic effect alone in this severe headache was poor and its main effect was to decrease the fever without notable improvement of the headache.

Narcotics:

IV morphine has been demonstrated to cause significant arterial dilation manifested by a reduction in systemic vascular resistance.

Cerebral vasodilatation may occur secondary to carbon dioxide retention.

We conclude that bolus injection of opioid should be used with caution on patients with ICP because they can transiently lower Mean Arterial Pressure (MAP) and increase ICP due to auto regulatory vasodilatation of cerebral vessels. [1]

Neurological assessment is of massive importance in patients with cerebral hemorrhage [4] and the use of opioid is believed to mask the neurological deterioration due to its central inhibiting effect.

Methods

Approval for this study was obtained from the Ethics in Human Research Committee (Notre Dame University hospital). Potential volunteers were given an information sheet and a briefing by a researcher, with an opportunity to ask questions. Written informed consent was obtained from all subjects agreeing to participate in both studies. Data was anonymised and information on the performance of individual participants was not made available to anyone outside of the study team.

All patients were presented with severe headache that responded poorly to Acetaminophen and other pain killers. A greater occipital nerve block along with the lesser occipital nerve block, using a nerve stimulator was done bilaterally on all ten patients using Bupivacine 0.125% 6cc on each side.

The block was performed every 6 hours.

No discomfort was observed no hematoma was seen.

Result:

After 30 minutes, the patients were observed and examined. Pain was almost subsided in ten patients. Only two patients reported no improvement of their headache.

Discussion:

Our study suggests that in the hands of experienced anesthesiologist (pain management), the greater occipital nerve block along with the lesser occipital nerve block, in managing the headache after intra cerebral hemorrhage and subarachnoid hemorrhage, is a very safe tool that provides relief and comfort for this group of patients.

As for the two cases that did not respond to this block we assume that either the block was a failure or didn't work at all.

References:

[1] Clinical review: critical care management of spontaneous intracerebral hemorrhage. Fred Rincon, Stephan A Mayer, critical care 2008, 12:237 PubMed abstract

[2] Schievink WI. Intracranial aneurysms. N Engl J Med 1997; 336: 28-40.

[3] van Gijn J, Rinkel GJE. Subarachnoid hemorrhage: diagnosis, causes, and management. Brain 2001: 124: 249-78.

[4] Wijdicks EFM. The clinical practice of critical care neurology, 2e. 2003; Oxford University Press.

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NEURAXIAL BLOCKADE IN PATIENTS WITH HEREDITARY NEUROPATHY WITH LIABILITY TO PRESSURE PALSIES (HNPP): A SERIES OF THREE CASE REPORTS J.W. Freeman, F. Lucci, J.-P. Lilley 3Anaesthetics and Intensive Care, Queen Elizabeth University Hospital, Birmingham, UK, Anaesthetics and Intensive Care, Tor Vergata University Hospital of Rome, Rome, Italy, Anaesthetics, BMI Edgbaston Hospital, Birmingham, UK Hereditary neuropathy with liability to pressure palsies (HNPP) is a common hereditary disorder affecting approximately 1 in 2500 of the population in the US. It is a slowly progressive neuromuscular disorder in which trauma to a single nerve may result in numbness and weakness. This can last from several minutes to days or months and may be permanent. The most commonly affected sites are the peroneal nerve, the ulnar nerve, and the radial nerve because of their relative vulnerability to trauma. HNPP is inherited in an autosomal dominant manner and is due to deletion of the peripheral myelin protein PMP-22 on chromosome. This is the same chromosome that is implicated in Charcot Marie Tooth (CMT) disease where there is a duplication of PMP-22.

We describe three separate cases of sensorimotor palsy in patients undergoing surgery under combined general and epidural anaesthesia who later subsequently were diagnosed with HNPP.

Case 1 was a 60 year old female presenting for total knee arthroplasty. This operation was performed under epidural regional inserted at level L2/3. A tourniquet was applied to the mid thigh and inflated to a pressure of 300mm and was inflated for 65 minutes. Postoperatively she complained of foot drop and numbness in the treated leg. This lasted for five days but recovered.

Case 2 was a 64 year old female presenting for colonic resection for carcinoma. Anaesthesia was provided by a combined general and regional anaesthetic technique with a low thoracic epidural. She was positioned supine on the operating table with her legs in lithotomy supports for four hours. Postoperatively she complained of weakness and numbness in the whole of her left leg including foot drop. Her neurology persisted for six days but she made a complete recovery.

Case 3 was a 32 year old female undergoing total hip arthroplasty. The procedure was performed under epidural regional anaesthesia combined with intravenous sedation. She was positioned in the left lateral position with her right arm lying in a Carter-Braine gutter support. Postoperatively she complained of weakness and loss of sensation in her right arm with marked wrist drop. She was investigated and was found to have both hand and foot small muscle atrophy which was previously asymptomatic. History enquiry revealed a distant relative had symptomatic Charcot-Marie Tooth disease and the patient was found to have a genetic mutation of PMP 22.

Discussion:

Regional anaesthesia for patients with a known hereditary neuropathy is not contraindicated however the possibility of developing a palsy should be discussed. Previously undiagnosed HNPP patients constitute a different situation and the possibility of a palsy secondary to nerve pressure is a reality. Loss of motor tone secondary to neuraxial blockade, poor or prolonged abnormal positioning on the operating table or the use of tourniquets can increase the risk. All patients should be warned of the risks and should be followed up with genetic testing.

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ANALGESIA FOR THE STERNOCLAVICULAR JOINT: WHAT SWIMMING THE BOSPORUS CAN TEACH US ABOUT ANATOMY B.F.S. Allen, J.-L. Horn Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA A 63 year-old female competitive swimmer presented for surgical repair of sternoclavicular joint dislocation. She had previously undergone surgery and successfully rehabilitated from an identical injury in the past. However, while swimming the Bosporus straight in Turkey during a competition, she reinjured herself and returned to the USA for treatment.

The patient was a highly athletic ASA 2 capable of > 10 METs. Her only comorbidities were Reynaud's disease and depression.

The intraoperative plan was for general endotracheal anesthesia with peripheral nerve block, standard monitors, 1 peripheral IV. The patient elected not to have a peripheral nerve block placed pre-operatively but consented for postoperative block if her pain was poorly controlled in PACU.

The anesthetic was uneventful and she was brought to PACU after a two-hour procedure. In recovery, the patient complained of 5 out of 10 pain and requested a peripheral nerve block.

A single-shot interscalene nerve block was performed using ultrasound guidance using a 2- inch Pajunk Sonoplex needle. Injection of 20 mL of Ropivicaine 0.5% with clonidine 100 mcg was performed in divided doses without paresthesia or signs of intravascular injection. Adequate appearance of spread in the interscalene groove was noted.

Within one minute of needle removal, the patient noted that the block had eliminated her pain “like magic” and she had zero pain. Immediate sensory exam of the patient showed deltoid weakness and decreased sensation of light touch over the superior aspect of the shoulder, but no sensory changes to light touch over the lateral neck, suggesting that her pain relief was due to interscalene block itself and unrelated to any spillover of local anesthetic to the superficial cervical plexus.

Several different options for regional anesthesia had been considered for this case. The sternoclavicular joint is a watershed area between the clavicle, which receives innervation from cervical nerve roots, and the sternum and chest, innervated by thoracic nerve roots. Likewise, depending on exact placement of the surgical incision, either thoracic dermatomes or cervical roots would transmit the incisional pain signals from the skin. The interscalene nerve block was chosen as the first intervention because it was easy to perform, required no patient repositioning, can cause coincident superficial cervical plexus block, and prioritized clavicular sensation, which we presumed took precedence over the sternal innervation. Had this initial interscalene block not proved effective, a subsequent T2 paravertebral block would have been considered. However, the interscalene block proved completely effective at eliminating the patient's pain, even without superficial cervical plexus blockade. This suggests the sternoclavicular joint is, like much of the remainder of the clavicle, innervated by the brachial plexus, specifically C5 and C6 nerve roots, and not by the superficial cervical plexus or thoracic roots.

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TAP BLOCKS USING DEXAMETHASONE WITH ROPIVICAINE DECREASES INPATIENT HOSPITAL STAY, A CASE REPORT C.J. Foster, D.J. Ferguson Surgery, Service of Anesthesiology, Carl R. Darnall ARMY Medical Center, Fort Hood, TX, USA T.A.P Blocks for Total Abdominal Hysterectomy Using Dexamethasone with Ropivacaine Decreases Inpatient Length of Stay, a Provocative Case Report

Christopher J. Foster, MD, Darrell J. Ferguson, MD

Carl R. Darnall Army Medical Center, Fort Hood, TX, USA

BACKGROUND

Over the past few years there has been a growing amount of evidence to support the use of Transversus Abdominus Plane (TAP) blocks for post-operative pain control for a variety of surgeries, including total open abdominal hysterectomies. [1,2,3] Similarly, Dexamethasone has been used successfully as an adjunct with local anesthetics to prolong the duration of analgesia for a variety of peripheral nerve blocks. [4,5,6] At Carl R. Darnall Army Medical Center (CRDAMC) in Fort Hood, TX, peripheral nerve blockade using Dexamethasone 4mg with Ropivicaine 0.5% has been successfully employed by the anesthesiologists for the past three years for hundreds of orthopedic procedures. More recently, the anesthesiologists have begun performing TAP blocks for total open abdominal hysterectomies with surprising results. The following is a specific case report describing these findings.

CASE REPORT

A 43 year-old female weighing 74.8kg presented for total open abdominal hysterectomy secondary to chronic pelvic pain due to pelvic adhesive disease. Her surgical history is significant for two prior Cesarean sections and an appendectomy. Her medical history is significant only for GERD and NIDDM, and both are well controlled with oral medications. After proper informed consent was obtained, the patient received bilateral TAP blocks pre- operatively in the regional block bay with Midazolam 2mg IV and Fentanyl 100mcg IV used for moderate sedation. Using ultrasound guidance, 30mL of Ropivacaine 0.5% with Dexamethasone 4mg was injected into each side of her abdomen, for a total of 60mL of Ropivacaine 0.5% and Dexamethasone 8mg. The patient then proceeded to the operating room, where she underwent general endotracheal anesthesia. Intraoperatively, her pain medications included a total of Fentanyl 150mcg IV and Hydromorphone 2mg IV in a titrated fashion. Surgical time was 107 minutes and she received a total 1000mL of Lactated Ringers and 500mL of hetastarch. Urine output was 200mL and total blood loss was 300mL. Her surgical course was complicated by the discovery of her urinary bladder being adhered to the uterus at the level of the internal os, necessitating a 2cm bilateral resection of the rectus abdominus muscle for proper visualization of the uterus, then subsequent muscle closure after successful removal of the uterus. Upon completion of the surgery, the patient was emerged from general anesthesia without incident and transferred to the Post-Anesthesia Care Unit (PACU) at 1335.

The patient's post-operative recovery went very well. In the PACU, she remained pain-free (0/10) as assessed by the Numerical Rating Scale and was discharged to the inpatient ward after thirty minutes without further pain medication. After arrival on the ward, she was placed on patient-controlled IV hydromorphone per routine by the OBGYN service at CRDAMC. Throughout her entire stay, the patient received a total of 3.6mg of hydromorphone, 1.7mg of which was administered in the first four hours after her arrival on the ward. She was transitioned to oral oxycodone 5mg/acetaminophen 325mg at 0800 the following morning and was subsequently discharged at 1400 later the same day, approximately 24 hours after leaving the operating room. During her inpatient stay, she reported a single pain score of 3/10 at 1800 on the day of surgery and a single pain score of 2/10 at 1200 on post-operative day one. All other pain scores were reported as 0-1/10. Upon discharge she was written a prescription for oxycodone 5mg/acetaminophen 325mg tablets PRN as well as Ibuprofen 800mg TID and was seen one week later for OBGYN follow-up without any complications or complaints of pain. Upon phone interview, the patient reported pain scores of 1/10-1.5/10 during her post-operative course leading up to her follow-up visit with OBGYN. She was unable to clearly identify when the analgesic effects of the TAP blocks wore off.

DISCUSSION

Patients undergoing total open abdominal hysterectomy typically experience a significant amount of post-operative pain which usually necessitates inpatient hospital stays of 48-72 hours. This case report demonstrates a patient who underwent pre-operative TAP blocks with Ropivacaine 0.5% and Dexamethasone 4mg bilaterally, whose hospital stay was substantially shorter than normal, and with lower pain medication requirements for post-operative pain control despite having an intra-operative course that would typically be indicative of a more painful post-operative recovery. Pending IRB approval, we plan to attempt to duplicate these results with a double-blinded, randomized controlled study to determine if the routine use of preoperative bilateral TAP blocks with Ropivacaine 0.5% and Dexamethasone 4mg can result in reliably shorter lengths of inpatient hospital stays with improved patient outcomes as measured by narcotic medication requirements and related side effects, as compared to Ropivacaine 0.5% alone or with placebo via sterile normal saline. By doing so, we hope to demonstrate a standardized, cost-effective approach to the peri-operative care and pain management of patients undergoing total open abdominal hysterectomy.

REFERENCES

1. Carney J, McDonnel JG, Ochana A, Bhinder R, Laffey JG. The Transversus abdominis plane block provides effective postoperative analgesia in patients undergoing total abdominal hysterectomy. Anesth Analg. 2008 Dec; 107(6): 2056-60.

2. Amr Y, Amin, S. Comparative study between effect of pre- versus post-incisional transversus abdominis plane block on acute and chronic post-abdominal hysterectomy pain. Anesthesia Essays and Researches. 2011, Vol. 5, Issue 1: 77-82.

3. Bonnet F, Berger J, Aveline C. Transversus abdominis plane block: what is its role in postoperative analgesia? Br. J. Anaesth. 2009; 103 (4): 468-470.

4. Vieira PA, Pulai I, et al. Dexamethasone with bupivacaine increases duration of analgesia in ultrasound-guided interscalene brachial plexus blockade. Eur J Anaesthesiol. 2010 Mar; 27(3): 285-8.

5. Movafegh A, et al. Dexamethasone Added to Lidocaine Prolongs Axillary Brachial Plexus Blockade. A&A. 2006 Jan, Vol. 102: 263-267.

6. Cummings, KC, et al. Effect of Dexamethasone on the duration of interscalene nerve blocks with Ropivacaine or bupivacaine. Br. J. Anaesth. 2011 Apr; 1093

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THROMBOELASTOGRAM WITH PLATELET MAPPING AS A MARKER OF ASSURANCE FOR PERIPHERAL NERVE BLOCK AND PATIENTS ON CLOPIDOGREL AND ASPIRIN J.J. Mukalel, H.C. Modi, A. Altamirano, E.G. G Pivalizza, D. Cattano Department of Anesthesia, University of Texas, Houston Texas Medical Center, Houston, TX, USA Long term inhibition of platelet function, with clopidogrel and aspirin, has been shown to improve outcome for those with cardiac disease (1). These patients are at high risk for general anesthesia, and the recommendations regarding urgent and emergent surgery are limited. The current recommendation for administering a regional anesthetic are to discontinue clopidogrel seven days prioir to surgery (2). Recently, thromboelastogram with platelet mapping (TEGPM) has been shown to be an effective tool for measuring platelet inhibition for patients on antiplatelet therapy (APT) (3). It has been demonstrated that patients are not equally effected by clopidogrel and aspirin and are therefore not at the same risk of bleeding. We present three cases where TEGPM aided in the safe placement of a regional anesthetic for intraoperative anesthesia.

77 year old female, American Society of Anesthesia (ASA) physical status 3, presenting for an open reduction internal fixation (ORIF) of a tibial and fibular fracture. She also had a 3-9 left sided rib fractures and small pneumothorax. Past medical history include chronic obstructive pulmonary disease, coronary artery disease, hypertension transient ischemic strokes, carotid stenosis and gastric reflux. She had a 40 pack year history of cigarette smoking, with the capability to climb 1 flight of stairs and daily housework without shortness of breath. We conducted an assay of her APT. The TEGPM demonstrated subtherapeutic inhibition of the ADP pathway, allowing us to confidently place an anesthetic subgluteal and femoral nerve block.

74 year old male, ASA 3, presenting for an ORIF open left distal fibular fracture. Patient had a history of hypertension and non-ST elevated myocardial infarction 4 weeks prior to his presenting fracture. After revascularization with coronary stenting, he had been taking aspirin and clopidogrel daily. Given that the patient was at moderate to severe risk for general anesthesia, we assayed his APT with the TEGPM and found subtherapeutic ADP and aspirin pathway inhibition. We therefore conducted a subgluteal sciatic and perivascular sapheneous anesthetic nerve block.

76 year old male, ASA 3, presenting for an ORIF left 4th and 5th metacarpal after a fall and fracture. His past medical history included a coronary artery bypass grafting more than 10 years ago, hypertension, peripheral vascular disease, chronic kidney disease 60 pack year history of tobacco use and recent bilateral carotid artery stenting. He also became dyspneic with minimal exertion. A TEGPM assay demonstrated subtherapeutic ADP and aspirin inhibition. We placed a single shot axillary nerve block for post operative analgesia and conducted the surgery with a general anesthetic uneventfully.

We feel the TEGPM has an application as point of care testing to help guide clinicians in placing peripheral nerve blocks. Although, it will be necessary to determine its sensitivity before firm recommendations can be made. Objective evidence of apt effect may assist individual decision making rather than blanket guidelines.

1. Di Minno DM et al. Intern Emerg Med. 2009 Aug;4(4):279-88 2. Horlocker T et al. RAPM 2010;35 (1):64-101 3. Collyer TC et al. BJA 2009;102:492-8

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NEAR MISSED WRONG SIDED BLOCKS R. Merman Anesthesiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA Introduction

As the use of peripheral nerve blocks is becoming more frequent, the number of blocks performed on the wrong side has become a more serious concern, warranting closer attention. In the state of Pennsylvania alone, it is estimated that “wrong-site” blocks represent 29% of all reports of wrong-site procedures in the surgical suites, the largest cohort of wrong-site procedures within a single specialty. Over time, wrong-site blocks have increased significantly from less than 20% of all reported cases to more than 40%, suggesting that the implementation of best-practice strategies to prevent wrong-site blocks lags behind other efforts to prevent wrong-site surgery.

Case

A 56-year-old Caucasian male with a past medical history significant for benign prostatic hypertrophy, hypertension, nephrolithiasis and severe degenerative disc disease of the right hip presented for right total hip replacement. The patient was evaluated prior to surgical procedure and consented obtained for placement of a lumbar plexus catheter preoperatively for postoperative pain management. Prior to performing the peripheral nerve block, the time- out protocol was performed and lateralization confirmed. The patient was then positioned, landmarks obtained and procedure site prepped and draped in a sterile fashion and vital signs monitored continuously throughout the procedure. Sedation was achieved with fentanyl and midazalam and the skin was then anesthetized with 1% lidocaine prior to needle placement. Lumbar plexus block was attempted with insulated needle but was terminated when attending anesthesiologist realized that the needle was placed on the wrong side. No local anesthetics were injected and patient was repositioned to correct side and lumbar plexus block performed and catheter placed and patient was subsequently taken to operating room to undergo surgery with no further sequelae.

Discussion

During the period of July 2002 to July 2011, the division of regional anesthesia and acute interventional perioperative pain of the department of anesthesiology at the University of Pittsburgh Medical Center has performed 135,090 blocks. During that time period, 7 blocks were performed on the wrong side, with at least 1 near-missed wrong-side block reported. The last wrong-side block complication led to system wide changes such as the implementation of wrong-side block policy (time-out protocol), education and training for physician as well as nursing staff. Despite these changes, this near-missed episode occurred a few months later. Upon further investigation, the root cause analysis revealed that in this case, the previously defined guidelines were not followed and many of the checklist points were overlooked or not done in correct order. Firstly, there were 2 successive nurses instead of one who participated in the time-out. Secondly, the time-out protocol was performed prior to the correct positioning of the patient and thirdly, the site of the block was not marked at the end of the time-out.

References

1.Cohen SP, Hayek SM, Datta S, Bajwa ZH, Larkin TM, Griffith S, Hobelmann G, Christo PJ, White R. Incidence and root cause analysis of wrong-site pain management procedures: a multicenter study. Anesthesiology. 2010 ; 112:711-8.

2.Fox MA, Webb RK, Singleton R, Ludbrook G, Runciman WB. The Australian Incident Monitoring Study. Problems with regional anaesthesia: an analysis of 2000 incident reports. Anaesth Intensive Care. 1993; 21:646-9

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THE IMPORTANCE OF ULTRASOUND IN THE PERFORMANCE OF TRANSVERSUS ABDOMINUS PLANE BLOCK IN A PATIENT WITH LATE STAGE DUCHENE MUSCULAR DYSTROPHY A. Wallace, D. Faulk, S. Bansal, D. Chatterjee, C. Ciarallo Anesthesiology, Surgery, Childrens Hospital Colorado, Anesthesiology, Aurora, Aurora, CO, USA Introduction

The advent of ultrasonography in regional anesthesia has popularized the Transversus Abdominus Plane (TAP) block for abdominal surgeries. The use of ultrasonography allows better localization and deposition of local anesthetic with improved accuracy.

Progressively degenerative neuromuscular diseases such as Duchenne's muscular dystrophy (DMD) typically alter both the size and composition of the muscle over time. There have been no reports on the use of ultrasound guided TAP blocks in patients with neuromuscular disease. We report the successful use of an ultrasound guided subcostal approach to the TAP block in an end stage patient with DMD undergoing laparoscopic Nissen fundoplication and gastrostomy placement who demonstrated severe atrophy of his entire abdominal musculature.

Case Report

A 27-year-old male with end stage DMD weighing 28kg presented for laparoscopic Nissen fundoplication and gastrostomy insertion. He suffered from severe scoliosis, contractures, a fused cervical spine, restrictive lung disease and required continuous bilevel positive airway pressure (BiPAP). An epidural or traditional TAP block for postoperative pain control was deemed unsuitable due to severe scoliosis and truncal contractures.

Following an uneventful anesthetic, bilateral subcostal TAP blocks were performed with ultrasound guidance to help decrease narcotic requirements and to help safely transition the patient from the ventilator post operatively. An ultrasound examination of the abdominal musculature revealed severely atrophied rectus abdominus muscles as well as almost non- existent external oblique, internal oblique or transversus abdominus muscles. Upon closer examination it was possible to identify a layer between the internal oblique and transversus abdominus muscle in the subcostal region and a 22 gauge short beveled block needle was inserted by an in plane technique with a linear 12mHz transducer. 10mL of 0.25% bupivacaine was injected on each side. Upon emergence the patient reported a successful block and was extubated to his home BiPaP settings on postoperative day one.

Discussion

Management of patients with DMD pose several anesthetic challenges. The degenerative progression of DMD also creates an immobility that results in severe muscular contractures and progressive muscle atrophy.

TAP blocks may be performed either by a traditional landmarks' technique1 or using ultrasound guidance. However the accuracy of truncal blocks has been reported to be greater when ultrasound is used2. Additionally, Hebbard3 and others have also reported on the lack of reliability of traditional TAP techniques for supraumbilical operations and have recommended alternative techniques such as the subcostal and subcostal oblique approaches to address these concerns.

Conclusion

The use of ultrasonography aided the performance of a technically difficult TAP block using an alternative subcostal approach in a patient with end stage DMD with scoliosis and contractures.

References

1. Rafi et al. Anaesthesia 2001;56:1024-26

2. Weintraud et al. Anesth Analg 2008;106:89-93

3. Hebbard et al. Anaesth & Int Care 2007;35:616-7

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ULTRASOUND-GUIDED SUPRACLAVICULAR BRACHIAL PLEXUS BLOCK:SINGLE VERSUS TRIPLE INJECTION TECHNIQUE FOR UPPER LIMB ARTERIOVENOUS ACCESS SURGERY E. Nada, S. Arab, D. Elrifai, M. Harbi, M.-S. Loran Anesthesiology, Cleveland Clinic, Cleveland, OH, USA, Anaesthesia, King Abdul Aziz Medical city, Riyadh, Saudi Arabia, Cleveland Clinic, Cleveland, OH, USA Objectives: The aim of this study was to compare the sensory block success rate between single injection (SI) versus Triple injections (TI) ultrasound guided spuraclavicular brachial plexus block for arteriovenous access surgery. (AVF)Methods: Prospective randomized double blind study. Ninety six end stage renal disease patients undergoing AVF creation or superficialization were equally randomized to receive either single injection (SI) or triple injections (TI) for upper limb vascular access surgery under regional anesthesia. After exclusion of 3 patient 46 patients were randomized in the SI group and 47 patients in the TI groups. In the SI the needle tip was positioned in the lower part of the plexus and 30 ml of lidocaine 1.5% mixed with epinephrine followed by Ropivacaine 0.5% in 1:2 ratio were injected. For TI group the same type of local anesthetic mixture in the same ratio was injected in 3 aliquots in the upper, middle and lower third of the of the cluster of the cluster of the plexus.The primary outcome was: the combined score of sensory blockade of the five nerves (the median, ulnar, radial, medial cutaneous nerve of the forearm and the musculocutaneous) at 5, 10, 15 and 20 minutes. The secondary outcomes were the onset time, the performance time, the success of each of the above nerves separately, the success rate of surgical anesthesia as measured by the lack of need of supplemental local anesthesia or the need to convert to general anesthesia on surgical stimulation and the rate of complications.

Results: The sensory block was significantly higher in the TI group at all times measured, P= (0.043, 0.002, 0.015, 0.043) for 5, 10, 15, 20 minutes respectively. The Muscolocautaneous (MC) nerve block was significantly faster in onset and more successful at all time intervals in the TI group P < 0.05. The onset time was significantly shorter in the TI group P< 0.002, while the time needed to perform the block was significantly longer in TI group P< 0.001, however the overall success of surgical anesthesia measured at 30 minutes was not statistically significant between the two groups ( p = 0.253) .Conclusion:

The TI technique was faster in onset and resulted in more successful sensory block of all nerves in the first 20 minutes, however the surgical success at 30 minutes was not statistically significant, although that was not statistically significant it was clinically significant in this group of sick patients. Also, Musculocutaneous nerve block was more successful in the TI technique which makes this technique more useful in certain procedures.

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MULTIPLE POSITIVE EPIDURAL TEST DOSES MAY INDICATE DIRECT EPIDURAL AND VENOUS CIRCULATION CONNECTION C.P. Moore, D.B. Auyong Anesthesia, Virginia Mason, Seattle, WA, USA A 76 y/o male presented for resection of liver lesion due to pancreatic adenocarcinoma. The patient had complete heart-block and was pacemaker dependent. For surgery, the pacemaker was programmed to DOO at a rate of 70bpm. Our plan included a thoracic epidural for analgesia. After placement of monitors, sedation, and positioning, the T 7-8 epidural space was accessed at 6.5cm depth with one attempt. The soft, spring-wound epidural catheter was threaded easily to 11.5cm and aspiration for blood or CSF was negative. A test dose of 3mL of lidocaine 1.5% with epinephrine 1:200,000 was administered through the catheter. Non- invasive blood pressure (NIBP) showed an increase in BP from 138/56mmHg to 151/60mmHg two minutes after test dose and decreased to 140's/50's upon repeat NIBP reading. An additional 2mL was injected with similar results - NIBP to the 150's/60's. The patient was alert, cooperative, and reported a bilateral sensory block to alcohol wipe over his abdomen. After induction, an arterial line was placed. Prior to surgical stimulation, monitoring of arterial blood pressure (ABP) showed an increase from 85/45mmHg to 158/106mmHg 30sec after repeat test dose, resolving within five minutes to baseline [Fig1]. No epidural infusions were started. The epidural catheter was removed after surgery. Another catheter was placed at T7-8. Again, a test dose showed ABP increased only minutes after administration. Two attempts were made one level above and below the initial catheter site with each test dose manifesting at least a 20% increase in ABP with no change in heart rate (70bpm-paced). The patient reported 10/10 pain upon arrival to the recovery which decreased to 0/10 on the NRS pain scale with accumulated administration of the test doses, in the absence of IV opioid. Although suspicion of a direct intravascular catheter placement was low given the scenario, the evidence of drug reaching the systemic circulation represented a higher than normal risk for systemic toxicity, and outweighed the benefits of epidural analgesia. Therefore, the epidural catheter was removed and the patient placed on a PCA. An epidural test dose is administered after epidural placement to assess for intravascular or intrathecal catheter location. A heart rate increase of >10bpm or, in the setting of unreliable heart rate response (beta-blockade, etc.), a systolic blood pressure increase of >15mmHg indicates a positive test dose for systemic delivery. [1] The assumption with a test dose is that the epidural space is not directly connected to the systemic circulation. New data may refute this assumption as direct connections between the spinal epidural space and the venous circulation have been identified in cadaver studies. [2] This case gives a clinical example of possible direct connections between the epidural space and systemic circulation. Our catheter was likely epidural, evidenced by decreased pain scores post-operatively and clinical loss of sensation. Additionally, it was likely not intravascular as test doses were delivered through a soft-tip catheter with four different uncomplicated placements at three different levels. 1)Guay, J. A&A. 2006; 102:921-9.

2)Buffington, C. RAPM 2011; 36:134-9.

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ELICITING PARASTHESIAS TO IMPROVE ULTRASOUND GUIDED ILIOINGUINAL BLOCKS R. Lange, C. Burnett Anesthesiology, Scott and White, Temple, TX, USA Background: Chronic pain from ilioinguinal neuralgia is frequently treated with nerve blocks using anatomic and ultrasound guided approaches. We will describe the use of a radiofrequency ablation probe to elicit parasthesias to improve clinical outcomes of ultrasound guided ilioinguinal blocks.

Case: We identified three patients followed in our clinic for chronic pain from ilioinguinal neuralgia. Two of the patients developed inguinal pain following inguinal hernia repair while the third developed symptoms after cardiac catheritization. Ilioinguinal nerve blocks were performed on all three using ultrasound as well as elicting parasthesias in the distribution of their pain using a radiofrequency ablation probe. All three patients underwent successful blocks using a combination of triamcinolone and bupivicaine while having no initial complications.

Conclusion: Direct visualization of the ilioinguinal nerve using ultrasound is thought to improve the quality of block as well as reduce the risk of complications. We added the use of our radiofrequency ablation machine to elicit parasthesias in the distribution of the patients pain. This technique may improve success rates of ilioinguinal blocks when used appropriately.

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IMPROVEMENT OF ALLODYNIA AND FUNCTIONING FOLLOWING 8 % CAPSAICIN TRANSDERMAL THERAPY IN THE SETTING OF COMPLEX REGIONAL PAIN SYNDROME STEMMING FROM BILATERAL ANKLE FRACTURES R. Alvarado, M. Eckmann UTHSCSA, San Antonio, TX, USA Capsaicin in the form of an 8% transdermal patch has emerged as a promising therapy indicated for chronic pain from post-herpetic neuralgia. More concentrated than other available ointment preparations (between 0.025% and 0.075%), this therapy has special precautions for application but offers the distinct advantage of avoiding systemic side effects compared to those of oral pain medications. Investigators and clinicians have used capsaicin 8% to treat off-label diagnoses such as HIV related neuropathy and other neuropathic pain states. We present a case of an active 28 year-old woman with complex regional pain syndrome (CRPS) type-I after bilateral ankle fractures sustained in a motor vehicle crash, who was successfully treated with Capsaicin 8% patch applications. The patient presented with sudomotor changes, spontaneous pain, and severe allodynia of both heels which prevented her from putting full pressure on the feet -- leading her to walk chronically on her toes. The patient had no significant improvement from oral medication management with opioids and membrane stabilizers. She underwent bimonthly intrathecal blocks, as an alternative to repeated bilateral lumbar sympathetic blocks, with some success until she developed a post-dural puncture headache. Subsequently she desired no further interventional pain therapies including spinal cord stimulation. The patient accepted capsaicin 8% patch applied to the heels and soles bilaterally after topical anesthesia. Initial reduction in pain started at 48 hours; at one week post application, she was able to walk using her heels and has continued to do so at 1 month post intervention. The response to 8% capsaicin patch therapy in this patient supports the need to investigate this method of therapy for other neuropathic pain syndromes, including CRPS.

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PULSED RADIOFREQUENCY OF THE BILATERAL C2 NERVE ROOTS FOR THE TREATMENT OF SEVERE REFRACTORY UPPER CERVICAL DYSFUNCTION INDUCED VERTIGO M. Martinez, A. Hays Department of Anesthesiology and Pain Medicine, University of Texas Health Sciences Center San Antonio, Anesthesiology and Pain Management, South Texas Veteran's Health Care System-Audie L, San Antonio, TX, USA Cervicogenic vertigo (CV) is a subset of vertigo provoked by a particular neck posture unrelated to the orientation of the head in regards to gravity. The incidence of CV is an estimated 20-58% in patients who sustain closed-head injuries or whiplash, most common in the 30-50 year old age group and the female population. Diagnosis is made based on lack of reasonable alternatives (i.e. ear disease, brain disease and migraines) and any or all of the following: dizziness, nausea, nystagmus on head turning, cervical disc herniation abutting spinal cord, readily apparent high-cervical disease, severe stiffness of the neck, symptoms elicited by massage or vibration of the neck, and no substantial hearing symptoms. The patient is 51 year-old medically retired Lt. Colonel with a past medical history of polytrauma sustained in the Gulf War, demyelinating polyneuropathy, cervical spondylosis, and recurrent cervicogenic headaches and nausea, responsive to radiofrequency ablation (RFA) of the C2- C4 dorsal rami/medial branches. The patient was admitted to the VA hospital for severe vertigo and nausea accompanied by headache, refractory to medical management. Physical examination revealed tenderness to palpation over bilateral C2-C3-C4 facets, increased pain with facet loading, 15% decreased range of motion in all planes, and delayed horizontal nystagmus with neck torsion testing. Neurological examination of the cranial nerves and cerebellum was unremarkable. Due to the success of bilateral C2-4 RFA in alleviating headaches and nausea, pulsed radiofrequency (PRF) at bilateral C2 nerve roots at 42 °C for a cycle time of 240-s was performed. The patient tolerated the procedure well without complications and reported an immediate decrease in his vertigo but not his headache. After 24 hours, the patient reported complete resolution of his headache and vertigo for the duration of the hospitalization and at 1, 3, and 6 month follow up. CV is managed with physical therapy, gentle mobilization, exercise, and instructions in proper posture. Medication management includes muscle relaxant, anti-emetic, empiric anti-migraine prophylaxis, and in patients with depression, anti-depression medications. In patients with cervicogenic pain, non-steroidal anti-inflammatory medications, tramadol, trigger point injections, and cervical blocks have been used. Anterior fusion has been successful in the treatment of cervicogenic vertigo but carries greater risk. The prognosis for CV is good; 75% of patients treated conservatively generally improve. We contemplated whether the resolution of vertigo occurred spontaneously as his headache resolved, however the fact that his vertigo improved 24 hours before his headache argues against this. It is not clear whether PRF of the C2 nerve root ablated abnormal afferent signals in the musculature involving the position of the head on the neck. RFA of the C2/3 joint involves modulation of the C2 dorsal ramus; we reasoned that PRF of the C2 nerve root, which includes the ventral ramus, would modulate central pathways involving the vestibular system. Although our patient had complete resolution of vertigo, and headache, the use of pulsed RF for the treatment of CV should be further evaluated with prospective studies.

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POSTOPERATIVE ANALGESIA VIA TRANSVERSUS ABDOMINIS PLANE (TAP) BLOCK FOR OUTPATIENT URETERAL REIMPLANTATION PROCEDURE K. Klimowicz, M. Visoiu, K. Boretsky, J. Chelly Anesthesiology, University of Pittsburgh Medical Center, Anesthesiology, Childrens Hospital of Pittsburgh of UPMC, Anesthesiology, Pittsburgh, Pittsburgh, PA, USA Introduction:

Single administration of local anesthetic and morphine preservative free via caudal space is used to provide adequate analgesia after ureteral reimplantations for pediatric patients, with the downside of overnight hospital stay (1). The use of Transversus Abdominis Plane (TAP) block has been described in children for analgesia following lower abdominal surgery (2). We report the use of bilateral TAP blocks to provide postoperative analgesia after bilateral intravesical ureteral reimplantation performed as an outpatient procedure.

Case description :

The patient is a 4 year old girl, 16.3 kg, with a history of recurrent febrile urinary tract infections, diagnosed with bilateral vesicoureteral reflux with ureteral duplication on the right side. The anesthetic technique included inhalational induction, endotracheal intubation, and TAP blocks performed at the conclusion of surgery. Intraoperatively the patient received fentanyl 4.3mcg/kg, acetaminophen per rectum 40mg/kg, ketorolac 0.3 mg/kg, and dexmedetomidine 1.25mcg/kg. At the end of the surgery, the patient was turned over to pain team for peripheral nerve blocks. After the skin was prepped with ChloraPrep , the three muscles of the lateral abdominal wall were visualized using a portable ultrasound (Bothnell,WA,USA) and a high frequency probe (SonoSite25n,13-6MHz,25mm broadband linear array) was placed oblique, pointing toward pelvis, very close to the iliac crest. The plane between the transversus abdominis muscle and the internal oblique was cannulated with a 24 gauge, 40 mm needle (SonoTap cannula, Pajunk®). After negative aspiration for blood, 8 ml of ropivacaine 0.5 % (40 mg) was administered to hydro dissect the transverses abdominis plane bilaterally. The patient was easily extubated and transported to postoperative care unit (PACU).

During PACU stay, the patient´s CRIES score was between 0-2 and no additional pain medications were administered. The patient spent in PACU 297 minutes and was discharged home in a stable condition. There were no complications from nerve blocks and no problems with voiding prior discharge.

Discussion:

A single administration of local anesthetics via the caudal space is a safe and simple way to provide postoperative analgesia but controversy exists if caudal blocks result in urinary retention (1) after ureteral reimplantation. Extravesical ureteral reimplantation has been reported as an outpatient procedure and has less morbidity compared to traditional intravesical reimplantation. In our case, with uncomplicated past medical history, the patient was an excellent candidate for outpatient surgery and in order to provide adequate pain control and facilitate discharge home we performed bilateral TAP blocks.

In summary, TAP blocks can be considered a feasible technique for the provision of analgesia for outpatient ureteral reimplantation in pediatric patients.

1.Fisher QA, et all. Postoperative voiding interval and duration of analgesia following peripheral or caudal nerve blocks in children. Anesth Analg 1993;76;173-7.

2.Carney J, et all. Ipsilateral transverses abdominis plane block provides effective analgesia after appendectomy in children: a randomized controlled trial. Anesth Analg 2010;111:998- 1003

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ULTRASOUND-GUIDED CONTINUOUS MEDIAN NERVE BLOCK TO FACILITATE INTENSIVE HAND REHABILITATION B.G. Maxwell, J.A. Hansen, J. Talley, C.M. Curtin, E.R. Mariano Anesthesia, Stanford University Medical Center, Anesthesia, Plastic Surgery, Stanford University, Plastic Surgery, Stanford, Stanford, Anesthesia, VA Palo Alto Health Care System, Palo Alto, CA, USA Background: Continuous brachial plexus blocks for postoperative analgesia following upper extremity surgery are well-described, but they can result in undesirable motor block and lack of specificity for minor hand procedures. We present the use of extended-duration continuous local anesthetic infusion via an ultrasound-guided median nerve catheter at the forearm (1) to facilitate hand physical therapy in a patient who had previously failed rehabilitation due to pain unrelieved by systemic opioids.

Case report: A 54-year old man presented with inability to flex his index finger after proximal phalangeal fracture. He underwent hardware removal and extensive scar release. He had severe post-operative pain that limited his ability to comply with hand therapy, which is required to maintain functional gains after surgery. A perineural catheter was placed under ultrasound guidance adjacent to the median nerve in the proximal forearm and a continuous infusion of ropivacaine 0.2% was initiated and maintained for 11 days. The patient had a focused sensory loss in the median nerve distribution, but maintained active flexion of the fingers. He subsequently was able to participate in hand physical therapy and discontinued the use of oral opioid medications.

Conclusions: Ultrasound-guided perineural catheters targeting terminal branch nerves may have potential benefits beyond the immediate postoperative period and in non-operative management of patients requiring physical therapy and rehabilitation.

References: 1. McCartney CJL, Xu D, Constantinescu C, Abbas S, Chan VWS. Ultrasound examination of peripheral nerves in the forearm. Reg Anesth Pain Med 32(5):434-9.

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ULTRASOUND-GUIDED LUMBAR PARAVERTEBRAL BLOCK FOR SURGICAL ANESTHESIA IN HIGH RISK PATIENTS UNDERGOING UNILATERAL INGUINAL HERNIA A. Al-Alami, A. Abouelezz, S. Sultan Anesthesia, International medical center, Anesthesia, IMC, Jeddah, Saudi Arabia Case series:We report three cases of unilateral inguinal herniorrpahy that were done under ultrasound-guided Lumbar paravertebral block(LPVB).

Case 1:76 year old gentleman whose past medical history(PMH)includes hypertension,diabetes,parkinson disease,myocardial infarction and stroke.His medications includes aspirin,enalapril,levodopa and metformin.The block was successfull and the surgery was uneventfull.Postoperatively he had no pain at his groin and his back.He received total of intravenous 1 g paracetamol.Next day he was discharged home.

Case 2:71 year old gentleman whose PMH includes hypertension,COPD, congestive heart failure,renal failure,dyslipidemia and myocardial infarction.Social history included alcohol,heroin and heavy tobacco abuse.His medications includes ventolin,bisopropol,Irbesartan, hydrochlorothiazide and budenoside.LPVB was done.Intraoperatively,the patient developed bradycardia,nausea and retching that were treated with glycopyrrolate,local anesthetics injected by the surgeon and antiemetics.Postoperatively he had minimal pain from his groin that was treated with 2 g intravenous paracetamol and 75 mg tramadol.However he had no pain at the block site.Next day he was discharged home.

Case 3:70 year old gentleman whose PMH included uncontrolled hypertension,iron deficiency anemia,malnutrition,chronic gastritis and prostate disease.His medications included iron and folate supplements,pantoprazol,doxazocin,amlodipine.The block was successfull and the surgery was uneventful.Postoperatively,after 12 hours he started to have moderate pain both at his groin and the block site that were treated with 1 g intravenous paracetamol and 50 mg tramadol.Next day he was discharged home.

The patient in case 1 was positioned laterally,while those in case 2 and 3 were positioned prone.All received propofol with ketamine sedation with full monitors and face mask oxygen during both the block and the surgery.Ultrasound guided longitudinal approach LPVB was done using curved probe frequency of 5 Hz(Ultrasonix,Richmond,Canada) with 22 G 90 mm Spinal Quincke needle (BD,Madrid,Spain).Hydro-dissection was used for needle tip localization.We first scanned over the sacrum laterally and counted the transverse processes from L5 to T12. We performed blocks between transverse processes extending from T 10 to L2.We injected 30-40 ml 0.5% bupivacaine with 2%lidocaine in the posterior one third of the posas muscle.

Discussion: Although ultrasound-guided LPVB with nerve stimulation was reported before(1),this is the first report describing real time ultrasonography without nerve stimulation to perform LPVB.The advantages of this technique are avoiding potential complications associated with blind needle entry such as renal injury, less back pain that was previously associated with using blunt block needle in the paraspinal muscles,avoiding patient discomfort secondary to nerve stimulation and less needle manipulations in the psoas muscle to obtain appropriate twitch,thus less time required to perform the block.These results however need to be validated in a randomized controlled prospective study.

Reference

1-Karmakar MK et al.Ultrasound-guided lumbar plexus block through the acoustic window of the lumbar ultrasound trident.BrJ Anesth 2008.100(4):533-

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CONTINUOUS LESSER PALATINE NERVE BLOCK FOR POSTOPERATIVE ANALGESIA FOLLOWING UVULOPALATOPHARYNGOPLASTY N.A. Ponstein, T.E. Kim, R. Goode, P. Borges, E.R. Mariano Anesthesiology and Perioperative Care Service, VA Palo Alto Health Care System; Stanford University, Anesthesiology and Perioperative Care Service, VA Palo Alto Health Care System; Stanford Universi,, Surgical Service, Otolaryngology, VA Palo Alto Health Care System; Stanford University, Surgical Service, Palo Alto, Anesthesiology and Perioperative Care Service, VA Palo Alto Health Care System, Stanford University, Palo Alto, CA, USA Background: Uvulopalatopharyngoplasty (UPPP) is a commonly-performed surgical intervention used to alleviate obstructive sleep apnea (OSA) symptoms. Patients with significant OSA are prone to developing opioid-induced respiratory depression, making the treatment of postoperative pain challenging in this population. Continuous peripheral nerve blocks have been shown to reduce postoperative pain and opioid requirements for other surgical indications but have not been previously described for palate surgery. We present the use of a continuous lesser palatine nerve block catheter as part of the multi-modal postoperative pain management of a patient with OSA following UPPP.

Case report: A 24-year old man with severe OSA presented for UPPP with scheduled postoperative hospital admission. The patient gave written permission to share the details of this case. Upon completion of the surgical procedure, but prior to emergence from general anesthesia, a 20-gauge multi-orifice epidural catheter was inserted via the left nasal passage (Fig. 1A), passed into the oropharynx, tunneled posteriorly within the anterior portion of the soft palate (Fig. 1B) with the aid of a 16-gauge angiocatheter, and sutured in place. The catheter was secured using clear adhesive dressings along the left cheek and anchored to the left shoulder. A continuous infusion of 0.2% ropivacaine at 2 mL/hour was delivered using a disposable infusion device for 2 days postoperatively in addition to prescribed oral and intravenous opioids. The patient reported numbness in his soft palate and posterior oropharynx with pain scores of 0-5 on a numeric rating scale (NRS; 0=no pain; 10=worst possible pain) throughout this time period and required 34 mg of intravenous morphine and 50 mg of oral oxycodone for breakthrough pain. The catheter was discontinued by the surgeon prior to discharge home. Approximately 4 hours after removal, the patient noted a 4- point increase in pain on the NRS which was manageable with oral oxycodone.

Discussion: Continuous lesser palatine nerve block may be a useful regional anesthetic technique in the multi-modal postoperative pain management of opioid-sensitive OSA patients undergoing UPPP and deserves further study.

References: 1) Anesth Analg. 2011 Oct;113(4):904-25; 2) Anesthesiology. 2006 May;104(5):1081-93

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TOTAL SPINAL ANESTHESIA AFTER PLANNED POSTERIOR LUMBAR PLEXUS BLOCKADE M.D. Danko, T. Kunkel Anesthesiology, University of Cincinnati, Cincinnati, OH, USA Background: The lumbar plexus innervates the extensor and adductor compartments of the thigh. Blockade of this plexus is useful for providing analgesia for many lower extremity surgeries and is an alternative to neuraxial analgesia (1). We present a patient in whom hamstring stimulation was noted during local anesthetic injection with the block resulting in total spinal anesthesia.

Case report: A 45 year old woman with osteoarthritis presented for right anterior total hip arthroplasty that was performed under general anesthesia. Postoperatively, the patient reported hip pain that was inadequately controlled with systemic analgesics. She was agreeable to attempting a lumbar plexus block for pain relief. The patient was placed in the left lateral decubitus position and the injection site was prepared in a sterile fashion. The top of the right iliac crest was used to identify the intercristal line. Then, the posterior superior iliac spine was palpated approximately 4 cm lateral to midline and a line was drawn parallel to the spine. The intersection of this line with the intercristal line was used as the site of needle insertion. A 21 G needle was advanced parallel to midline until the L4 transverse process was contacted. The needle was then redirected in a medial and caudal fashion until quadriceps stimulation was produced. With the muscle twitch maintained at 0.6 mAmp, an injection of Ropivacaine 0.5% was initiated. At the beginning of the injection brief hamstring stimulation was noted, but this stimulus dissipated and the injection was continued for a total volume of 25 ml. Aspiration at 5 ml intervals throughout the injection was negative for blood or cerebrospinal fluid.

Less than 2 minutes after injection, the patient became agitated and complained of dyspnea. She then became unresponsive and hypotensive. Her pupils were noted to be small, but still reactive and naloxone was administered with no response. The patient's trachea was intubated for ventilatory support, hypotension was managed with volume resuscitation and a phenylephrine infusion, and intravenous sedation was provided with propofol. No seizure activity or arrhythmias were noted. Approximately 3 hours after the injection, spontaneous ventilation returned and the patient was noted to have upper extremity motor function. At 6 hours post-injection, lower extremity motor function resumed and mechanical ventilation was discontinued the following morning. At that point she was able to recall numbness that spread from her legs to her head before becoming unconscious. The patient made a full neurologic recovery with no evidence of adverse sequelae upon discharge from the hospital.

Discussion: Hamstring stimulation during a posterior lumbar plexus block indicates sacral plexus stimulation and implies that needle placement is too far medial or caudal (2). Thus, the presence of the hamstring twitch during injection in this case was likely caused by migration of the needle medially to stimulate a spinal nerve with continued needle migration into the intrathecal space. For posterior lumbar plexus blocks in which hamstring stimulation is seen on injection, we recommend aborting the injection due to the possibility of needle tip migration away from the intended injection site.

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References:

1. Awad IT and Duggan EM. Posterior Lumbar Plexus Block: Anatomy, Approaches, and Techniques. Reg Anesth Pain Med 2005; 30(2): 143-149.

2. Capdevila X, Coimbra C, and Choquet O. Approaches to the Lumbar Plexus: Success, Risks, and Outcome. Reg Anesth Pain Med 2005; 30(2): 150-162.

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FLUOROSCOPIC GUIDED REMOVAL OF BROKEN PERI-NEURAL CATHETER IN AMBULATORY SETTING T. Malik, J. Enayati Anesthesia, Critical Care, Pain Medicine, University of Chicago, Chicago, IL, USA The benefits of continuous peripheral nerve blocks & increasing complexity of ambulatory surgical procedures have made the use of ambulatory CPNBs more common. The uses of ultrasound & stimulating catheter designs have increased the success rates for CPNBs- yet potential for complications still exists. Problems removing CPNBs have been previously reported, albeit rare in the literature. Herein, we report a case of a difficult to retract supraclavicular catheter which was removed using fluoroscopic guidance without any surgical intervention.

Case report: 46 year old female scheduled for a right arthrotomy for release of an elbow flexion contracture under regional anesthesia. To improve pain control, & for prescribed aggressive physical therapy, the surgeon requested continuous regional analgesia post-op. A supraclavicular wire-reinforced Arrow catheter was placed using ultrasound without stimulation via an in-plane technique. Anticipating prolonged use, it was tunneled 3 cm subQ & a bio-patch was placed at the exit site. The patient experienced excellent analgesia, participated in therapy, & was discharged after 3 days. She was connected to an On-Q pump, home instructions were given, & daily phone contact maintained. On the 6th day post-op, the patient reported that the catheter was “stuck” & aggressive pulling had caused breakage. She came to the Pain Clinic, & 6 inches of wire were presenting from the skin. The wire had uncoiled & there was no sheath over it (image1). She denied paresthesia & had intact sensory & motor exams. Fluoroscopic images of the catheter revealed no knotting (image2). After cleaning the catheter & site using chloraprep, the catheter was steadily pulled under live fluoro without progress. Most of the tension was coming out at the primary insertion site. A suture removal kit was used to open up the primary insertion site & the catheter was pulled out with fluoro guidance (image3). The wire was cut & the subQ portion of the catheter was pulled out separately. The wire tip was partly bent but there was no other obvious damage.

Discussion: Ambulatory perineural catheters provide great pain relief at home, require little care by the patient to manage them, yet still require constant clinical supervision. The most concerning issue that has surfaced are catheters getting “stuck” requiring simple management to surgical intervention. There are different proposed mechanisms, including mechanical issues created during catheter insertion, and biologic responses to the catheter or wire. In our case tunneling dose not seems to be the issue as the sheath slipped out easily, catheter was threaded only 4 cm beyond the needle tip & there was no knotting of the catheter or damaged catheter tip. The sheath slipped off the wire easily, & the catheter still would not come out & seemed to be suck at mostly at the primary insertion site. Pulling on the catheter seemed to uncoil the catheter more. Fluoroscopy helped us decide upon non- surgical intervention versus sending the patient to the OR for surgical intervention. By applying steady tension we could see the wire slowly moving out after widening the primary insertion site, and that led us to continue with persistent tension, & after few minutes the wire retracted completely.

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PARAVERTEBRAL CATHETER FOR COMPLEX SPINE SURGERY E. Nada, E. Farag, S. Kolli Anesthesiology, Cleveland Clinic, Cleveland, OH, USA 62 years old female with history of chronic pain had a Complex spine surgery for correction of thoracolumbar kyphosis. Before surgery the patient was on 50 mcg/hr. transdermal fentanyl every 72 hs, and gabapentin 300 mg three times daily.

The surgery entailed a Saber-slash incision done from the tip to the lowest rib on one side to the middle of the abdomen, T11 rib resection which has been used later as a graft, the diaphragm was taken down , the psoas muscle was taken down largely from the chest wall and access to the spine was obtained. At the end of the procedure small pleural rents were created and a soft drain was placed in the thorax and tunneled out through separate stab incision, an intrapleural catheter was also inserted by the surgeon. Ropivacaine 0.2% was run in it at a rate of 6/4/15; she was left the whole night in surgical intensive care unit intubated and sedated. After extubation IV Hydromorphone PCA and home medications were started but the patient's pain was largely uncontrolled and was at 10/10 on numerical rating scale at the surgical incision.

On examination it was found that the pleural catheter was not covering the surgical pain. We decided to place a paravertebral nerve catheter using ultrasound guidance. The right paravertebral space was located at T 9-10, a catheter was threaded and a 20 ml of 0.5% Ropivcacaine was injected. The patient reported reduction of her pain score to 2/10, a continuous infusion of Bupivacaine 0.1% and fentanyl 2mcg /ml at a rate of 5ml/h basal and a bolus of 4 every 15minutes to a maximum of 4 boluses/h. We were able to discontinue the basal from PCA, and added Oxycontin 10 mg q 12 hours. On the following day the paravertebral infusion were increased to 7ml/h basal a bolus of 4 every 15minutes to a maximum of 4 boluses /h, decrease the IV PCA demand down to 0.3 due to increased sleepiness.

The Paravertebral catheter was removed after 3 days and she was started on oral Hydromorphone 4 mg every 4 hours , and her transdermal Fentanyl dose was increased to 150 mcg/h, her postoperative pain was controlled to level that was close to her baseline.

Discussion

We will discuss the various ways of pain management in complex spine surgery especially in chronic pain patients we will elaborate more on the intrapleural and paravertebral analgesia.

A153

WORKUP OF A COMPLICATION FOLLOWING A FEMORAL NERVE BLOCK D. Beausang, R. Shechter Anesthesiology, Thomas Jefferson Univ. Hospital, Philadelphia, PA, USA This is a case of unilateral lower extremity paralysis following arthroscopic knee surgery preceded by an uneventful femoral nerve block. This case exemplifies the importance of a neurologic exam prior to regional techniques and outlines the necessary post-operative evaluation of alleged block-associated complications.

The patient is a 16 year-old female who underwent right knee arthroscopy and open medial patellar femoral ligament reconstruction. She had a history of postoperative urinary retention. Preoperative neurologic exam of the patient's lower extremities was negative. The preoperative, ultrasound guided, femoral nerve block and intraoperative period were unremarkable. The patient was discharged on POD#0 after refusing lower extremity exam from physical therapy.

On POD #4, the patient contacted her surgeon and reported right leg weakness. The surgeon immediately informed us of the patient's complaint and further consultation was arranged.

On POD #5, a physiatrist's examination discovered global weakness of her right lower extremity with normal sensation and intact reflexes. A limited nerve conduction study showed normal tibial nerve activity, offering no explanation for the patient's inability to plantar flex. On POD #7, the patient saw a neurologist whose exam revealed intact sensation, +2 ankle jerk reflex bilaterally and a + Hoover sign. The neurologist was unable to define an organic injury that would account for involvement of both sciatic and femoral nerve distributions. A follow-up EMG, months later, was normal.

During the post-operative period we kept regular contact with the teenage patient's mother who reported that her daughter continued to drag her leg despite aggressive and almost daily physical therapy. The family on their own accord sought psychiatric evaluation, records from which were not released. Six months following surgery the patient developed acute onset urinary retention, which resolved spontaneously. Full motor function in her right lower extremity had also recovered.

Our impression is that the patient suffers from conversion disorder. With conversion-induced lower extremity paralysis, Hoover sign is positive and, according to the DSM, “with gait, one finds that the weakened leg is dragged rather than circumducted”. Both clues were present in our patient.

The management of a peripheral nerve injury is dictated by the severity of the deficit. Minor deficits, the result of neuropraxia, require patient reassurance and frequent patient contact, usually without further diagnostic intervention. Major deficits, the result of axonotmesis or neurotmesis, must be directed promptly to a specialist for further diagnostic tests. These include electrophysiology testing, Doppler and MRI. An EMG can differentiate radiculopathies, plexopathies and neuropathies within days of the injury but cannot identify the etiology. Doppler imaging is used to evaluate nerve integrity, inflammation or compression and is used in conjunction with nerve conduction. MRI is ideal for detecting early signs of nerve compression, nerve inflammation and nerve trauma and is also ordered in conjunction with nerve conduction.

A154

THE USE OF CONTINUOUS NERVE CATHETERS FOR A BELOW THE KNEE AMPUTATION IN A HIGH RISK CARDIAC PATIENT J. Johnson, J. Adams Anesthesia, University of Nebraska, Omaha, NE, USA Peripheral vascular disease (PVD) poses a challenge to the anesthesiologist to maintain homeostasis in poorly perfused organ tissues with particular attention to cardiac and cerebrovascular circulations. Tipping the delicate balance can have profound effects leading to tissue ischemia and further end-organ damage. This case illustrates how a continuous peripheral nerve catheter (CPNC) can provide adequate anesthesia for limb amputation in a patient with PVD complicated by severe aortic stenosis and a recent stroke.

The patient was an 87 year man old presenting with right foot gangrene. His aortic valve area was 0.56cm2 and he suffered an ischemic stroke two months prior with residual aphasia and dysphagia. An angiogram showed heavily calcific disease throughout the right lower extremity. His ejection fraction was 65-70% and there was EKG evidence of a past inferior infarct. Carotid dopplers indicated right internal carotid artery occlusion. The surgery consultant recommended a below the knee amputation and the patient was admitted the night prior to have both a sciatic and femoral nerve catheter placed. A continuous infusion of 0.2% ropivicaine at 6ml/hour was run overnight in each the catheter. Prior to surgery, he received 100mg of lidocaine with 25mg of ropivacaine and 1ml of HCO3 in both catheters. 150ug of fentanyl was given over the first 45 minutes of surgery; a propofol/ketamine infusion was started for patient comfort for the remaining 45 minutes. Mean arterial pressures were maintained above 60 using a total of 30mg of ephedrine, and his heart rate did not exceed 80 bpm. The post-operative course was uneventful and his catheter was removed on Post-op day 3, and the next day he was discharged to a skilled nursing facility. His cognitive status was determined to be at his pre-operative baseline.

CPNC can provide adequate anesthesia with relative hemodynamic stability in critically ill patients. A neuraxial technique would be contraindicated with a history of severe aortic stenosis, and general anesthesia also carries the possibility of dramatic hemodynamic shifts. One of the primary goals in this case was to avoid further cognitive impairment by challenging an already vulnerable cerebral blood supply. A CPNC performed on admission would address these concerns and provide excellent post-op pain control. The continuous catheter was chosen over a single shot nerve block because it intuitively provides more control of sympathetic tone and allows titration for analgesia. Ephedrine was used peri- operatively, but this coincided with the initiation of the propofol/ketamine. Overall, this case illustrates the usefulness of CPNC in critically ill patients. While current research agrees on immediate benefits of this technique, there is limited evidence showing long-term improvements in quality-of-life measures. However, it would be prudent to further investigate CPNB as the primary anesthetic technique in patients susceptible to cardiac and vascular events.

Sources:

1. H Baddoo. A Preliminary Report on the Use of Peripheral Nerve Blocks for Lower Limb Amputations. Ghana Med J. 2009 March; 43(1): 24-28.

2. Brian IIfeld. Continuous Peripheral Nerve Blocks: A Review of the Published Evidence. Anesth and Analg 2011;113:904-15.

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CERVICAL PLEXUS BLOCK FOR LEFT HEMI-THYROIDECTOMY IN A PATIENT ON THE WAITING LIST FOR LUNG TRANSPLANT O. Duany, M. Fajardo, M.F.J. Garcia Anesthesiology, Indiana University, Indianapolis, IN, USA, Anesthesiology, Hospital del Tajo,, Madrid, Anesthesiology, Hospital del Tajo, Aranjuez, Spain The use of regional anesthesia for thyroid surgery is a reasonable alternative to General Anesthesia in patients who represent a high surgical risk. This case presentation is about a 51 years old male patient, 175 cm of height, 68 kg of weight, with a past medical history of being a smoker, neurofibromatosis type II (Von Recklinghausen disease), severe bullous emphysema with recurrent pneumothoraces, traumatic T12 fracture with T11-L1 spinal fusion and hypercholesterolemia. His medications included Spiriva, Seretide, Simvastatin and use of home oxygen. At the moment of this study, the patient was a candidate for lung transplantation due to severe limitation in his functional capacity secondary to his pulmonary pathology. As part of the pre-transplant work up, a cold nodule was found on the left thyroid lobe, which prevented including this patient in the transplant waiting list until it was surgically corrected. The case was discussed with our hospital Tumor Board and the Surgery, Anesthesia and Pulmonology services, where we decided to proceed with the surgery with regional anesthesia to avoid mechanical ventilation and general anesthesia. We performed a left superficial and deep cervical plexus block which allowed a successful hemi- thyroidectomy with no pain in the intra-operative period. In PACU and the ward, the patient had absent pain at 0, 2, 4, 6 and 8 hours, not needing opioids for pain control. He was discharged home the next day.

Cervical plexus block allows anesthesia on the dermatomes from C1 through C4, which innervate the anterolateral portion of the neck, the mandible and the clavicle. Superficial and deep cervical plexus blocks are used in our hospital due to being easy to use, with little hemodynamic impact and allowing performing surgery with the patient awake. Aspiration done before the injection of the local anesthetic is important to avoid accidental intravascular or intrathecal injections Patients using this technique have a sooner recovery and less undesired symptoms such as nausea, vomiting and pain. In patients with a high surgical risk, like the one presented in this case report, regional anesthesia allows to minimize the stress response and a satisfactory post-operative pain control.

The thyroidectomy with regional techniques also allows minimizing health care cost and diminishing the time of hospital stay. Some studies have reported savings of up to 30% by using this type of anesthesia.

A156

ULTRASOUND-GUIDED SUPERFICIAL CERVICAL PLEXUS BLOCK FOR MINIMALLY-INVASIVE PARATHYROIDECTOMY IN A PATIENT WITH EISENMENGER'S SYNDROME L. Eppihimer, B. Spektor Anesthesiology, Emory University School of Medicine, Atlanta, GA, USA INTRODUCTION

Superficial cervical plexus blockade (SCPB) has become increasingly utilized for minimally- invasive parathyroidectomy (MIP). We present a case of a patient with uncorrected patent ductus arteriosus (PDA) complicated by Eisenmenger's Syndrome presenting for parathyroidectomy performed under minimal sedation with an ultrasound-guided SCPB as a primary anesthetic.

CASE

A 52-year-old female with uncorrected PDA, severe pulmonary hypertension and Eisenmenger's syndrome presented for elective MIP. This ASA 4 patient had hypercalcemia with elevated parathyroid hormone secondary to isolated right lower parathyroid adenoma. Patient had baseline dyspnea on exertion chronically on home O2 of 2 L/min. Preoperative EKG demonstrated normal sinus rhythm, right atrial enlargement, RV hypertrophy, and RBBB. Echocardiogram revealed a PDA, RV hypertrophy, and mean pulmonary artery pressures of 88-93 mmHg; left ventricular EF was 60%. Baseline upper extremity SpO2 was 90-96% and lower extremity SpO2 was 80-88%. Preoperative collaboration of the surgeon, anesthesiologist, and cardiologist resulted in a decision to proceed with unilateral SCPB with minimal MAC; intraoperative goals were avoidance of hypoxemia, hypercarbia, and systemic hypotension to prevent worsening of pulmonary hypertension and cyanosis. After obtaining consent, IV access with air filter, and invasive arterial monitoring, the patient was placed supine with head turned contralaterally. Ultrasound guidance with high-frequency probe in axial orientation was utilized to identify the mid sternocleidomastoid (SCM) muscle. A 25g 1.5” needle was advanced out-of-plane just deep to the posterior SCM, and 15 ml of Ropivacaine 0.5% was incrementally injected along the posterior SCM in a cranio-caudad direction. 1 mg of midazolam facilitated the block. In the OR, both upper and lower extremity SpO2 were monitored. Inhaled nitric oxide was immediately available. Preoperative sensory testing revealed decreased pinprick sensation in all 4 terminal branches of the SCP. After applying O2 via nonrebreather facemask, low-dose dexmedetomidine infusion was initiated at 0.2 mcg/kg/hr with no bolus. Minimal supplemental local anesthesia was administered by the surgeon. The patient was communicative throughout and maintained upper and lower SpO2 of 100% and 99%, respectively. Post-operatively, patient was transferred to PACU without pain complaints. She was monitored in the cardiac ICU overnight and then discharged.

DISCUSSION

The SCP originates from the anterior rami of the C1 to C4 spinal nerves and gives rise to 4 terminal branches: the greater auricular, lesser occipital, transverse cervical, and supraclavicular nerves. Landmark-based SCPB was previously evaluated for MIP and was found equally efficacious relative to combined deep and SCPB. Of import, several prior reports using higher volume multi-level deep cervical plexus blocks showed increased incidence of ipsilateral diaphragmatic paralysis. Prior comparison between landmark- and ultrasound-guided SCPB techniques revealed similar efficacy and side effect profile. We offer this case highlighting the utility of US-guided SCPB in a patient with Eisenmenger's syndrome to control pain, prevent cyanosis, and maintain hemodynamic stability.

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PUDENDAL ENTRAPMENT NEUROPATHY, A RARE COMPLICATION OF PELVIC RADIATION THERAPY F. Elahi, D. Callahan, W. Wu, C. Lassalle, B. Beutler, A.K. Bhandary Universty of Iowa, Coralville, IA, USA Pudendal nerve entrapment (PNE), also known as Alcock canal syndrome,is an uncommon source of chronic pain, in which the pudendal nerve (located in the pelvis) is entrapped or compressed. In this case study we describe a 59 year-old male with stage IV prostate cancer with Gleason Score of 9 . He was diagnosed 3 years ago with subsequent chemotherapy and radiation therapy. He was referred to Pain Clinic for chronic perineal pain. The patient has been suffering chronic pelvic pain, that was started insidiously about two months after completion of adjuvant chemotherapy and radiation therapy to the pelvic region. He described his pain as it is mainly located in the left perineal region behind the testicular sac. There is occasional radiation of pain to the testicles and the left groin. The patient describes the pain as deep, aching, sharp, and burning at times. Sitting for a prolonged period of time greatly exacerbates the pain. The pain has not been controlled with oral pain medications including high dose of gabapentin, morphine, physical therapy. He was seen by outside facility pain service and did not received improvement with caudal epidural steroid injection, pelvic trigger point injection and ganglion Impar injection.

The patient had a recent normal pelvic MRI.

After thorough evaluation and review of prior imaging, based on his presentation with the diagnosis of pudendal entrapment neuropathy, we decided to perform a left pudendal nerve block under the double guidance of Ultrasound /Fluoroscopy.

In this article we discuss the suggested pathophysiology of entrapment neuropathy after radiation injury, importance of double imaging guidance to have more accurate localization, and finally a review of literature will be provided.

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USE OF PERIPHERAL NEUROMODULATION IN THE TREATMENT OF CHRONIC REFRACTORY SACROILIITIS T. Evazyan, F.M. Ferrante Department of Pain Management/Anesthesiology, University of California Los Angeles, Santa Monica, CA, USA Introduction

Sacroiliitis is a chronic pain condition which causes significant pain and suffering for patients who have the condition. We are describing a novel use for peripheral neuromodulation in a patient with chronic refractory sacroiliitis.

Materials and Methods

Mrs. D is a 57 year old female who has suffered from sacroiliac pain since June 2008. Throughout the three year course of her treatments, she benefited greatly from repeated bilateral sacroiliac joint injections. She underwent a total of nine sacroiliac joint injections over the span of three years, initially with corticosteroid and eventually with hylan G-F 20. With each injection, she had significant benefit in pain and physical functioning. Unfortunately, she only would receive benefit for a maximum of two months at a time. After the short lived results of the injections wore off, she would experience debilitating pain ranging greater than 8/10 pain on the visual analog scale (VAS). Throughout her care, she was medically managed on pregabalin, lidocaine patches, as well as ibuprofen. Our institution had attempted to perform denervation of the sacroiliac joint with radiofrequency ablation throughout her care given her positive response. However, her insurance company denied coverage. In an attempt to provide the patient with long-lasting analgesia, we performed a peripheral neuromodulation trial placing percutaneous leads over the sacroiliac joints. The patient experienced greater than 90% relief of pain with this technique. The patient then underwent permanent implantation of bilateral peripheral neurostimulator leads, with bilaterally implanted implantable pulse generator (IPG) units.

Results

At multiple follow up visits, the patient continues to endorse greater than 90% resolution of her chronic pain, improved physical functioning, and improved quality of life. She has been able to discontinue use of pharmacological agents for treatment of her pain.

Discussion

Peripheral neuromodulation has been used in one case at our institution as an effective means of treating chronic refractory sacroiliitis. Given the success, the use of this technique for sacroiliac pain will likely be attempted in additional appropriately selected patients.

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EPIDURAL BLOOD PATCH IN PATIENT WITH A HISTORY OF SPINAL FUSION AND INTRATHECAL PAIN PUMP A.J. White, C. Burnett Anesthesiology, Texas A&M University at Scott and White Hospital, Temple, TX, USA Bv Epidural blood patch (EBP) is a widely accepted treatment for post-dural puncture headache (PDPH), which is postulated to result from persistent leakage of cerebrospinal fluid (CSF) following dural puncture. EBP is frequently utilized in obstetrical anesthesiology. The use of EBP is not well described in patients with a history of surgical disruption or obliteration of the epidural space. Questions abound to the safety and efficacy of epidural blood patching within that patient population. We present a patient with PDPH following intrathecal pain pump implantation complicated by history of multilevel lumbar spinal fusion with implanted hardware.

Case Report

A 49 year old female with chronic lower back pain with history of lumbar fusion presented for severe headache of three weeks duration. Patient had medical history significant for six lumbar vertebrae and spinal fusion at the L5-L6-S1 levels with pedicle screws, intradiscal cages and bone grafts at multiple levels. Patient had undergone intrathecal pain pump implantation in the lumbar region 7 weeks prior. Patient presented with a severe headache with photophobia and nausea that started 3 weeks after the implantation. The headache was alleviated by lying flat and worsened with standing or mobilization. Patient had attempted and failed conservative management. Patient was seen in referral per request of surgical team for evaluation for possible EBP. Patient was felt to be candidate for EBP and subsequently was counseled on risks and benefits of procedure and consent forms were signed.

Patient was placed in prone position in fluoroscopy suite and the lumbar spine was imaged which demonstrated six lumbar vertebrae and spinal hardware bilaterally, extending from L5 through S1 and an intrathecal pain pump with catheter insertion at the L5-L6 level. An 18 gauge Touhey needle was inserted at the L5-L6 level to the right of midline and advanced into what was felt to be the epidural space using loss-of-resistance technique and intermittent fluoroscopy. Injection of 2 mL of contrast demonstrated satisfactory cephalad and caudal epidural spread. A total volume of 20 mL of autologous blood was then injected through the needle. The patient was observed in clinic for a brief period post-procedure and then discharged home with complete resolution of her headache. Follow up at three weeks demonstrated continued relief from the headache.

Discussion

EBP is a widely utilized treatment for PDPH that has been studied and validated primarily in obstetrical anesthesia with reported success rates in the 70-95% range. A paucity of information exists in patients with postsurgical changes that can cause a potential alteration or complete obliteration of the epidural space. Patients with history of lumbar spinal surgery could theoretically have no epidural space or significant alteration of the space, thus rendering loss-of-resistance technique impossible and/or potentially dangerous. Additionally, with no epidural space, the question arises whether blood patching will be effective and by what mechanism the blood patch works in such a patient. EBP was performed successfully in this case, but further research into this modality of treatment is probably warranted so that the mechanism of action and safety profile can be further elucidated before widespread adaptation can be advocated for.

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KETAMINE AS AN ADJUNCT FOR THE LONG-TERM SEDATION AND ANALGESIA OF A PATIENT WITH A LEFT VENTRICULAR ASSIST DEVICE (VAD) AND AN OPEN CHEST A. Gupta, C. Charles Kato, E. Viscusi Thomas Jefferson University Hospital, Philadelphia, PA, USA Introduction Critically ill patients are often deeply sedated for patient comfort, but also to reduce the sympathoadrenal response to injury. Younger patients or patients chronically on opioids and benzodiazepines can be difficult to manage despite very high doses due to development of tolerance. Escalating opioid doses may prove ineffective and esacerbate opioid tolerance and hyperalgesia. Ketamine may be a useful adjunt in a mutimodal approach to maximize both pain control and sedation. We report a case utilizing ketamine as an adjunctive agent for the long-term sedation and analgesia of a patient with a Left Ventricular Assist Device (LVAD) and an open chest in the surgical cardiac care unit (SCCU).

Case description A 5'10”, 110 kg 28 year old male with no past medical history was admitted due to worsening shortness of breath and lower extremity edema. His work up included an echocardiogram which demonstrated a 20% ejection fraction with severe mitral valve regurgitation, pulmonary arterial pressure of 60/30, wedge pressure of 28, right atrial pressure of 22, and cardiac output of 4.5. Nonischemic cardiomyopathy was suspected at this point. The clinical management consisted of inotropic support of milrinone and nesiritide and subsequently Extracorporeal Membraneous Oxygenation (ECMO) for decreased cardiac function as well as antibiotics for sepsis secondary to a suspected hospital acquired pneumonia. Ultimately, on admission day 32, he was placed on LVAD but his chest remained open due to inadequate intraoperative hemostasis.

Next day, the acute pain service was consulted because of inadequate sedation and pain uncontrolled by conventional means. By this time, the patient was receiving 300mcg/hr of fentanyl and 18mg/hr of midazolam, and was characterized as “-3 moderate sedation” according to the RASS scoring system. Ketamine was started at 20mg/hr with a 10mg bolus and was subsequently titrated up to 60mg/hr over the next six hours. A dramatic decrease in the amount of fentanyl and midazolam required for sedation and analgesia was observed. Over 24-36 hours, fentanyl dosage decreased from 18 to 4mg/hr while his fentanyl remained at 50mcg/hr from its original high of 300mcg/hr. During this time, his RASS score was “-2 light sedation.”

Discussion Ketamine may be a useful adjunt to sedation in patients who also require analgesia and are on high doses of opioids. The addition of ketamine may improve patient comfort while decreasing opioid requirements and reduce opioid tolerance and hyperalgesia. Ketamine's effects on the cardiovascular system are well known and can be potentially beneficial even in critically ill patients with carefully titrated doses. Indirectly, it acts as a sympathetic stimulant via centrally mediated mechanisms to generate increases in heart rate, blood pressure, and cardiac output - all of which can be valuable to patients suffering from acute hypovolemic, septic or cardiogenic shock. Other useful effects of ketamine include its bronchodilating effects and minimal respiratory depression. In summary, a multimodal sedative and analgesic regimen utilizing ketamine in selective patients that require very high doses of opioids and benzodiazepines can be innovative and offer important advantages.

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LAP TAP-LAPAROSCOPIC ASSISTED TAP BLOCK M. Guzman Community Hospital East, Fishers, IN, USA Introduction: The ability to abolish postoperative pain has been elusive for surgeons and anesthesiologists. Major abdominal surgery with minimal postoperative pain has evolved with the introduction of Transversus Abdominis Plane(TAP) blocks. TAP blocks have shown to decrease post- operative pain for procedures above(subcostal TAP) and below(posterior TAP)the umbilicus. Difficulties with percutaneous TAP block placement are multifactorial. Hospitals may not have appropriate ultrasound equipment. Many anesthesiologists have been reluctant to obtain proper regional anesthesia training. Surgeons usually dread long turnover times between cases, and their impatience does not allow for an acute pain service. Laparoscopic assisted transversus abdominis plane(LAP TAP) block is presented as an efficient,safer alternative for placement of single and continuous TAP blocks for all laparoscopic surgeries.

Methods: One can place a TAP block under direct vision during a laparoscopic procedure. With the abdomen distended with carbon dioxide, the surgeon can safely view the peritoneum in the area of a typical posterior or subcostal block. An apparatus(needle/sheath) is used by the surgeon or anesthesiologist. Using the apparatus under direct camera vision, one penetrates through skin,fat,external oblique,internal oblique, and slides the apparatus in a plane parallel to and above the peritoneum. The distal end of the apparatus is now in the belly of the transversus rectus muscle. Local anesthetic is given through tubing connected to the apparatus. If the apparatus is too deep, the surgeon will see the apparatus, and upon injection of local anesthetic, one will notice the peritoneum surface ballooning. The apparatus should then simultaneously be withdrawn out of the patient and then local anesthetic injected until a bulge(Figure 1) is noted. This bulging indicates separation of the transversus rectus from the internal oblique. Continuous LAP TAP blocks involve placing a catheter through the apparatus and then connecting to an infusion device.

Discussion: LAP TAP reliability is dependent on recognition of the transversus rectus muscle. Percutaneous TAP block ultrasound pictures will show a two dimensional diamond shaped spread of local anesthetics(Figure 2). This spread correlates with the snow cone bulge seen at the LAP TAP site. Confirmation of local anesthetic placement for a LAP TAP can also be performed by ultrasound(Figure 3).

Reduction in postoperative narcotics,nausea, and length of hospitalization are many of the described benefits for percutaneous TAP blocks. Laparoscopic surgery is usually presented as minimal invasive, however these procedures are still invasive. Many patients have pre- existing pain issues and are chronically taking oral opiods. General and bariatric surgeons at our institution have been educated with LAP TAP blocks. Surgeons now elect to place single LAP TAP blocks for almost every laparoscopic surgery. Continuous LAP TAP catheters are placed in patients with chronic opiod history. Clinical results for LAP TAP by our surgeons have been equivalent to TAP blocks placed by anesthesia. LAP TAP is presented as a safe alternative for single and continuous TAP blocks for laparoscopic procedures.

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EPIDURAL BLOOD PATCH FOR TREATING BENIGN INTRACRANIAL HYPOTENSION A. Abd-Elsayed, H. Sachdeva University of Cincinnati, Cincinnati, OH, USA Introduction:

Spontaneous intracranial hypotension (SIH) is caused by spontaneous spinal cerebrospinal fluid (CSF) leaks and is known to cause orthostatic headaches. It is an important cause of new headaches in young and middle-aged individuals, but initial misdiagnosis is common. While there are different treatment modalities, an epidural blood patch (EBP) is the most common procedure to be performed if conservative management fails. We present 4 cases with spontaneous intracranial hypotension that failed treatment with epidural blood patches.

Case presentations:

Our patients were four women with an average age of 30 years. All of them reported a positional nature of the headache being severe on sitting or standing. They denied any history of epidural puncture or any other neuroaxial procedures in the previous 10 years. Patients reported severe headache 6-8/10 in severity that interfered with their daily activities. Physical examination and MRI were normal. We treated the four patients with conservative measures that included bed rest, oral hydration and caffeine. The conservative management failed and after discussing the risks and benefits the patients agreed to receive epidural blood patches. We preformed EBP using 20 mL of autologous blood injected into the epidural space at the level of L3-4. The patients were then placed in the supine position for 30-40 minutes prior to discharge. All patients reported reduction in the headache severity before discharge by 40- 60%. Daily phone follow ups revealed a return of headache to base line level in all patients within 5-7 days. We are in the process of performing more imaging investigations to our patients trying to localize the exact site of the leak.

Conclusion:

The success rate of epidural blood patch in treating spontaneous intracranial hypotension is controversial. In our series; none of our patients' headaches were improved after receiving treatment with an epidural blood patch. There are several reasons that can lead to the failure of the epidural blood patch such as an anterior leakage or leakage from a nerve root sleeve.

References:

1.Schievink WI. Spontaneous spinal cerebrospinal fluid leaks and intracranial hypotension. JAMA 2006; 295:2286-2296.

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SUCCESSFUL USE OF CONTINUOUS PERIPHERAL NERVE CATHETERS FOR THE TREATMENT OF A RAPIDLY PROGRESSING COMPLEX REGIONAL PAIN SYNDROME I IN A PEDIATRIC PATIENT S. Sukumvanich, R. Bryskin Mayo Clinic and Nemours Children's Clinic, Jacksonville, FL, USA Successful Use of Continuous Peripheral Nerve Catheters for the Treatment of a Rapidly Progressing Complex Regional Pain Syndrome I in a Pediatric Patient.

Complex regional pain syndrome (CRPS) in a pediatric patient is an infrequent but incapacitating disorder that results after a minor injury (1,2). The pathophysiology of pain is unclear but is thought to be mediated through the peripheral, autonomic and central nervous systems (3). Therapy traditionally focuses on restoration of function and employs a multidisciplinary approach with pharmacotherapy (analgesics, antidepressants, anticonvulsants and NMDA receptor antagonists), physical therapy (PT), psychotherapy and interventional management (sympathetic plexus blockade, spinal cord stimulation and regional anesthetic blocks) (4). In several recent studies/case-reports, continuous peripheral nerve blockade (CPNB) has been demonstrated to be effective in resolving CRPS I when utilized in combination with either Bier blocks or Ketamine infusion (5,6). We describe a 14- year-old patient with complex regional pain syndrome I in her left leg triggered by a bug bite that progressed rapidly despite a combination of traditional pharmacologic and therapeutic modalities. She had complete resolution of symptoms following insertion of continuous Sciatic and Femoral peripheral nerve block catheters and 96 hours local anesthetic infusion plus aggressive PT. • Compare and contrast the different techniques for treatment of CRPS I in a pediatric patient.

• Discuss the importance of the peripheral, autonomic and central mechanisms in the maintenance of pain.

• Realize the potential of continuous LA infusion via peripheral nerve catheter for the treatment of CRPS in pediatric patient resistant to traditional modalities. References:

1.Lee, et al. Physical therapy and cognitive-behavioral treatment for complex regional pain syndromes. J Pediatr 2002.

2.Mogilevsky, et al. Complex regional pain syndrome-a multifaceted disorder requiring multidimensional care: case study. J Pain 2007.

3.Forouzanfar, et al. Treatment of complex regional pain syndrome type I. Eur J Pain 2002.

4.Wilder, et al. Reflex sympathetic dystrophy in children. Clinical characteristics and follow- up of seventy patients. J Bone Joint Surg Am 1992.

5.Dadure, et al. Continuous peripheral nerve blocks at home for treatment of recurrent complex regional pain syndrome I in children. Anesthesiology 2005.

6.Everett,et al. A unique presentation of complex regional pain syndrome type I treated with a continuous sciatic peripheral nerve block and parenteral ketamine infusion: a case report. Pain Med 2009.