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Home , Femoral nerve block, Local anesthesia, Vein stripping

Alexandria Journal of Anaesthesia and Intensive Care 44

Femoral versus Spinal for Lower Limb Peripheral Vascular By Ahmed Mansour, MD Assistant Professor of Anesthesia, Faculty of , Alexandria University.

Abstract Perioperative cardiac complications occur in 4% to 6% of patients undergoing infrainguinal under general, spinal, or epidural anesthesia. The risk may be even greater in patients whose cardiac disease cannot be fully evaluated or treated before urgent limb salvage operations. Prompted by these considerations, we investigated the feasibility and results of using with infiltration of the genito4femoral nerve branches in these high-risk patients. Methods: Forty peripheral vascular reconstruction of lower limbs were performed under either spinal anesthesia (20 patients) or femoral nerve block with infiltration of genito-femoral nerve branches supplemented with local infiltration at the site of dissection as needed (20 patients). All patients had arterial lines. Arterial blood pressure and electrocardiographic was continued during surgery, in PACU and in the intensive care units. Results: Operations included femoral-femoral, femoral-popliteal bypass grafting and thrombectomy. The intra-operative events showed that the mean time needed to perform the block and dose of and sedatives needed during surgery was greater in group I (FNB,) compared to group II [P=0.01*, P0.029* , P0.039*], however, the time needed to start surgery was shorter in group I than in group II [P=0. 039]. There were no block failures in either group, but local infiltration in the area of the dissection with 2 ml (range 1-5 ml) of 1% lidocaine was required in 4 (20%) patients in FNB group vs none in the spinal group. The recovery times showed that the nerve block resolution and time to micturition was longer [P0. 0001 [p=0.0001*, p=0.00032*] in the Spinal group (group II) as compared with patients receiving femoral nerve blockade (group I). Moreover, the incidence of requiring analgesics in PACU and postoperative complications was higher in group II than in group I [P0.021*, p0.0028*]. Conclusion: lower limb vascular reconstruction can be done under (femoral nerve block with infiltration of genitor-femoral nerve branches) with acceptable complication rates specially in patients with high-risk diseases.

Introduction Furthermore, the most prevalent anesthetic techniques, general and Most patients presenting with lower neuro-axial anesthesia, are associated limb ischemia are elderly, often with with some complications and have extensive co-morbidity. Early symptoms side-effects that make them less than ideal include intermittent claudication and leg in such patients. For general anesthesia ulcers, progressing to critical ischemia these include myocardial depression, (rest pain and tissue loss) or acute postoperative nausea and vomiting(3), sore ischemia (white leg). Patients commonly throat(4), and myalgias(5) On the other hand, have widespread atherosclerosis involving postoperative backache(6), post-dural coronary, cerebral and renal vasculature, puncture headache(7), slow resolution of and 10-year mortality in these patients is the block or the development of postural 45%, mainly as a result of coronary and hypotension(8), can complicate the cerebral events. About 20% of patients postoperative course of neuro-axial progress to critical ischemia within 6 years anesthesia and result in delayed discharge. and require surgery. (1) By confining the anesthesia to the region that is being operated upon, nerve block Pen-operative cardiac complications anesthesia can avoid many of the occur in 4% to 6% of patients undergoing disadvantages of both general and infra-inguinal revascularizatioii under neuro-axial anesthesia.(9) general, spinal, or epidural anesthesia. The purpose of this study was to The risk may be even greater in patients investigate the feasibility and results of whose cardiac disease cannot be fully using femoral nerve block with infiltration of evaluated or treated before urgent limb genito-femoral nerve branches in these salvage operations.(2) high-risk patients.

AJAIC-Vol. (9) No. 1 Marsh 2006 Alexandria Journal of Anaesthesia and Intensive Care 45

Methods was set at 2 Hz, while the intensity of stimulating current was initially set to The study was carried out- on 40 deliver I mA and then gradually decreased patients scheduled for either elective or to less than 0.5 mA. Paraesthesia was emergency peripheral of never intentionally sought, and a multiple the lower limbs. After written informed technique was used, eliciting consent was obtained, patients scheduled specific muscular twitches on nerve for peripheral vascular surgery were stimulation to confirm exact needle randomly assigned to receive either spinal location. anesthesia or femoral nerve block with genito-femoral nerve branches infiltration. Femoral nerve block (FNB) was Patients excluded from randomization performed with patients in the supine included those in whom regional position, with the negative electrode anesthesia was contraindicated. connected to the needle and the reference Contraindications for regional anesthesia electrode connected to the lateral thigh; included preexisting coagulopathy (i.e., contractions of the quadriceps femoris patients receiving preoperative infusions of muscle were sought. After the contractions heparin or urokinase), operations requiring were obtained, 25 mL of the local arm , and prior lower back surgery. anesthetic (10 ml of 1% lidocaine and 15 ml of 0.5% bupivacaine) was injected. Demographic data, , Branches of the genitofemoral nerve were and surgical and medical history were blocked by of 7 mL obtained from the patient and from the of 1% lidocaine. In case of specific medical record. All patients underwent complaints related to the surgical preoperative 12-lead electrocardiography.

procedure (i.e., pain on instrumentation), After an intravenous (IV) cannula infiltration with (1% had been inserted in the forearm, all lidocaine) was used instead of intravenous patient received IV 7 ml/kg infusion of supplementation. lactate Ringer’s . Then, patients Sensory level was evaluated by were allocated to receive either spinal loss of pinprick sensation (20-gauge anesthesia or femoral nerve block hypodermic needle), whereas motor blockade was evaluated using a modified Intra-operative monitoring was Bromage scale (0 = no motor block; 1= hip carried out with radial artery cannulation, blocked; 2 = hip and blocked; 3=hip, pulse oximetry, noninvasive blood knee and ankle blocked). Haemodynamic pressure measurements, and dual-channel variables were measured every 5 min electrocardiographic monitoring (leads II during the first 30 min after block and V5). Pre- consisted of oral placement, then every 15 min until the end diazepam (5-10mg) often supplemented of surgery; further assessments were with either intramuscular meperidine performed every 30 min Clinically relevant (25-50 mg) or intravenous fentanyl (25-50 hypotension was defined as a decrease in micro gram). systolic arterial blood pressure by 30% or Spinal anesthesia was performed more from baseline values, and it was with hyperbaric bupivacaine 0.5% initially treated with 200 ml IV infusion of (7.5-10mg). This was administered via a Ringer’s lactate solution; if this proved to 22-G spinal needle at L4-L5 or L3-L4 with be ineffective, an IV bolus of phenylephrine the patient in the lateral decubitus position, (40-50 mcg) was given. Clinically relevant operative side down. Patients were kept in bradycardia was defined as heart rate this position for 10 mm after the intrathecal decrease below 45 bpm, and it was treated injection. with 0.5 mg IV atropine.

Femoral nerve block (FNB) was The time lasting from skin performed with the aid of a nerve stimulator disinfection to the end of local anesthetic using a short-beveled, Teflon-coated injection (preparation time) and then to stimulating needle. Stimulation frequency achieve surgical anesthesia (readiness for

AJAIC-Vol. (9) No. 1 Marsh 2006 Alexandria Journal of Anaesthesia and Intensive Care 46 surgery) were recorded. Surgical (SPSS/version 14) software. The statistical anesthesia was defined as the presence of test used as follow: mean and standard adequate motor (complete motor blockade deviation, student t-test, Chi-square test, in the Spinal group or inability to move the the 5% was chosen as the cut off level of ankle and the knee of the operated limb in significance. the femoral group) and sensory (loss of pinprick sensation at T12 in the Spinal Results group, or in the femoral nerve distribution in the femoral group) blocks. The quality of This study was carried out on 40 the block was judged according to the need patients scheduled for peripheral vascular for supplementary IV analgesics and surgery of the lower limbs. The operations : adequate nerve block = neither included were thrombectomy, femoral- sedation nor analgesics required to femoral and femoral-pophiteal bypass complete surgery; inadequate nerve block grafts. Twenty patients in group I received = need for. additional analgesia (25 mcg IV FNB with subcutaneous infiltration of bolus of fentanyl) or sedation (1mg genito-femoral nerve branches while 20 ) required to complete surgery; patients of group II received spinal failed nerve block = general anesthesia anesthesia. required to complete surgery. The two groups had comparable After completion of surgery, patients demographic data (Table1). However, were managed in the post-anesthesia care Figure I showed a significant haemodynamic unit (PACU) for the first 2 h with continuous changes in group II which were clinically electrocardiographic and arterial pressure irrelevant (the decrease in MAP, the number monitoring. After discharge from the of patients needing phenylephrine and the post-anesthesia care unit, patients were total amount of phenylephrine given was transferred to intensive care unit (ICU). more in group11). Intravenous morphine (2-5 mg) and/or meperidine (12.5-50 mg) were given for The intra-operative events (table 2) analgesia as needed while the patient showed that the mean time needed to remained in a monitored care setting. Data perform the block and dose of analgesics regarding the time lasting from the end of and sedatives needed during surgery was local anaesthetic injection to complete greater in group I (FNB) compared to group resolution of sensory and motor blocks, 11[P=0.0V’,P=0.029*, P=0.039*],.However, urination, as well as occurrence of adverse the time needed to start surgery was events or complications, and pain shorter in group I than in group II [P 0.039*]. treatments were also recorded. Also, the duration of surgery and quality of The patients pain control regimens the block were comparable in both groups were changed to intramuscular meperidine, (There were no block failures in either or oral analgesics on transfer to a general group, but local infiltration in the area of the patient care floor. On the 1 st postoperative incision with 2 ml (range 1-5 ml) of 1% day, patients were given subcutaneous lidocaine was required in 4 (20%) patients heparin (5,000 units every 12 h) until in FNB group vs none in the spinal group). ambulating; oral aspirin (81 mg) was then given daily until discharge. Also, the Table (3) summarizes the recovery times. patients were interviewed using a Nerve block resolution and time to standardized questionnaire. Back pain, rnicturition was longer [P= 0.0001*, P neurological sequelae, post-dural puncture =0.00032*] in the Spinal group (group 11) headache (PDPH) and patient satisfaction as compared with patients receiving were investigated. femoral nerve blockade (group I). Moreover, the incidence of pain requiring The Data was collected and analgesics in PACU and postoperative entered into the personal computer. complications was higher in group II than in Statistical analysis was done using group I [P0.021*,p 0.0028*]. Statistical Package for Social Sciences

AJAIC-Vol. (9) No. 1 Marsh 2006 Alexandria Journal of Anaesthesia and Intensive Care 47

Table (1): Demographic Data Group I Group I P Value n20 n20 Age (years) 68±12 66±10 0.123 Sex Male 13 15 0.49 Female 7 5 Weight (kg) 69+11 71±12 0.31 Type of surgery Thombectomy 8 10 Femoral-Popliteal bypass 9 6 0.61 Femoral artery grafting 3 4

Group I Group II 120

110

100       90         80

70 e n n n n n n n n n n n n n iv i i i i i i i i i i i i i t m m m m m m m m m m m m m ra 5 0 5 0 5 0 5 0 5 0 5 0 0 e 1 1 2 2 3 4 6 7 9 0 2 5 p 1 1 1 -o re P Figure (1): Pen-operative changes in mean arterial blood pressure in both groups.

Table(2):Intra-operative Clinical Data. Group I Group II P Value Mean time to perform the block 14±3 9+4 0.0l* Mean time to start surgery (min) 15 ± 5 20 + 5 0.039* Duration of surgery (min) 124 ± 35 127 ± 30 0.28 Quality of the block Adequate 16 (80%) 18 (90%) Inadequate 4 (20%) 2 (10%) 0.41 Failed 0 0 Mean dose of intraop. 105 + 60 50 ± 60 0.029* analesics/ 3.8 + 1.5 2.5 + 1.0 0.039*

Table (3): Post-operative Data. Group I Group II P Value Time to nreve block resolution 185±42s 127+39 0.0001* Time to urination 135±46 225±83 0.00032* Pain in PACU/ ICU requiring analgesia 45% 70% 0.021* Complications Headach none 20% Backache 10% 30% 0.0028* Vomiting 5% 10% Patient satisfaction 80% 50% 0.041*

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Discussion postoperatively in patients in the FNB group than in the spinal anesthesia group. This In patients scheduled for vascular may be due to the fact that patients surgery, atherosclerotic disease is highly undergoing lower extremity peripheral prevalent. Haemodynamic reactions are vascular surgery do not experience the often aggravated when spinal analgesia is same intensity of postoperative pain as (10) used in this population. The cumulative patients undergoing orthopedic or other results of many studies showed that the major intra-abdominal procedures(14) incidence of cardiovascular morbidity and Moreover, diabetics over time often develop mortality is similar regardless whether the sensori-motor peripheral neuropathies, patient receives a general, spinal, or which may minimize their (11,12,13) epidural anesthetic Therefore, requirements (15) optimal anesthetic management for Taylor et al. reported successful use peripheral vascular surgery requires that of FNB for long saphenous stripping the anesthesia be handled expeditiously, (LSVS) operation in 1981 (16). The authors with minimal residual postoperative used 20 mL of 1% lidocaine for FNB and anesthetic effects and side-effects that infiltration of local anesthetic at the may affect the outcome of such operations sapheno-femoral vein junction, but the and local nerve block may represent a safe recovery times were not reported. Since alternative in such conditions. then, the authors in a subsequent reply to a In this study, femoral nerve block comment have recommended use of 0.5% (FNB) resulted in a more favorable bupivacaine for the same operation(17) recovery, fewer complications, and better Our results are consistent with patient satisfaction than spinal anesthesia Barkmeier et.al.(2) who found that limb in patients undergoing lower limb vascular salvage operations can be done under local surgery. anesthesia with acceptable complication Femoral nerve block (FNB) results rates. In selected patients with high-risk in anesthesia in the antero-medial thigh coronary artery disease, local anesthesia and medial aspect of the lower leg. This has theoretic and practical advantages and distribution covers the entire operative field, should be considered an alternative to except the inguinal region, where sensory general or regional anesthesia. innervations is derived from the branches Since FNB does not result in of the genito-femoral nerve. The first sign complete anesthesia of the lower extremity of successful blockade was the inability of as spinal anesthesia does, patients the patient to extend the leg at the knee frequently express anxiety when the joint. This was then followed by onset of surgeon is manipulating the leg even in the surgical anesthesia in the described absence of surgical stimuli. Thus, although distribution. the quality of anesthesia did not appear to This study demonstrated that, even differ between the groups, the patients in though performing a femoral nerve block the FNB group received significantly more took slightly longer than spinal anesthesia, fentanyl and midazolam. Verbal the time required to achieve surgical reassurance and short-acting intravenously anesthesia and resolution of the block after administered sedatives before the surgical the end of the procedure was shorter when manipulation is begun is very important performing lower limb vascular surgery here, as it is with most other regional using a femoral nerve block and a multiple anesthesia techniques. Additionally, local injection technique. infiltration of the area of the dissection may

When the motor component of the occasionally be needed. It should be block had dissipated, allowing for early recognized, however, that discomfort on ambulation, the remaining sensory surgical manipulation is not considered a blockade after FNB provided longer lasting failure to achieve blockade of the femoral postoperative analgesia as evidenced by nerve. decreased need for analgesics in the Moreover, although the sample size PACU/ICU and the first 12 hours of this study is not large enough to provide

AJAIC-Vol. (9) No. 1 Marsh 2006 Alexandria Journal of Anaesthesia and Intensive Care 49 new information on the incidence of long saphenous vein stripping surgery. cardiovascular and neurological Anesth Analg 1997; 84:749-52. complications or other adverse events such 10- Lundorff L, Dich-Nielsen JO, as post-dural puncture headache and Laugesen H, Jensen MM. urinary retention, it should be pointed out Single-dose spinal anesthesia versus that peripheral nerve blocks are associated incremental dosing for lower limb with a lower morbidity than spinal vascular surgery. Acta Anaesthesiol anesthesia. Scand. 1999 Apr; 43(4):405-l0. In summary, our results show that 11- Damask MC, Weissman C, and Todd FNB results in excellent anesthesia in G. General versus epidural patients undergoing peripheral vascular anesthesia for femoral-popliteal surgery of the lower limb. When compared bypass surgery. I Clin Anesth 1990; to spinal anesthesia, this technique resulted 2:71-5. in a more favorable recovery, higher patient 12- Rivers SP, Scher LA, Sheehan E, satisfaction and fewer complications. Veith FJ. Epidural versus general

anesthesia for infrainguinal arterial References reconstruction. I Vasc Surg 1991; 1- Andrew B Lumb. Anesthesia for 14:764-70. vascular surgery on extremities. 13- Christopherson R, Beattie C, Frank Anesthesia and Intensive Care SM, Norris EJ, Meinert CL, Gotllieb Medicine 2004 June; 5: 207-2 10. SO, Yates H, Rock P, Parker SD, 2- Barkmeier LD, Hood DB, Sumner DS, Perler BA, Williams GM. Mansour MA. Local anesthesia for Perioperative Ischemia Randomized infrainguinal arterial reconstruction. Anesthesia Trial Study Group: Am I Surg 1997 Aug; I 74(2):202-4. Perioperative morbidity in patients 3- Wafcha ME, White PF. Postoperative randomized to epidural or general nausea and vomiting. anesthesia for lower extremity 77:162-184, 1992. vascular surgery. Anesthesiology 4- Monroe MC, Gravenstein N, 1993; 79:422-34. Saga-Rumley S. Postoperative sore 14- Allen PD, Walman T, Concepcion M, throat: effect of oropharyngeal airway Sheskey M, Patterson MK, Cullen D, in orotracheally intubated patients. Covino BG: Epidural morphine Anesth Analg 1990; 70:512-6. provides postoperative pain relief in 5- Philip B. Ambulatory anesthesia. peripheral vascular and orthopedic Semin Surg Oncol 1990; 6:177-83. surgical patients: A dose-response 6- Schneider M, Ettlin T, Kaufmann M, study. Anesth Analg 1986; 65:165-70. el a!. Transient neurological toxicity 15- Bode, Robert H, Lewis, Keith P, after hyperbaric subarachnoid Zarich, Stuart W. Cardiac Outcome anesthesia with 5% lidocaine. Anesth after Peripheral Vascular Surgery: Analg 1993; 76:1154-7. Comparison of General and Regional 7- Cruickshank RH, Hopkinson JM. Anesthesia. Anesthesiology: Volume Fluid flow through dural puncture sites. 84(1) January 1996 pp 3-13 An in vitro comparison of needle point 16- Taylor EW, Fielding JW Keighley types. Anesthesia 1989; 44:415-8. MR, Alexander-Williams J. Long 8- Pflug AE, Aasheim GM, foster C. saphenous vein stripping under local Sequence of return of neurological anaesthesia. Ann R Coil of Surg of function and criteria for safe Engi 1981; 63:206-7. ambulation following subarachnoid 17- Taylor EW, Fielding JW, Keighley block (spinal anesthetic). Can MR, Alexander-Williams J. Anaesth Soc 11978; 25(2): 133-9. Comment to the letter: Long 9- Vloka JD, Hadzic A, Mulcare R, saphenous vein stripping under local Lesser JB, Kilain E, Thys DM. anesthesia. Ann R Coil of Surg of Engl Femoral nerve block versus spinal 1981; 63:364 anesthesia for outpatients undergoing

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AJAIC-Vol. (9) No. 1 Marsh 2006