Anesth Pain Med 2011; 6: 270～274 ￭Case Report￭
Femoral and sciatic nerve blocks for total knee replacement in an obese patient with a previous history of failed endotracheal intubation −A case report−
Department of Anesthesiology and Pain Medicine, School of Medicine, Catholic University of Daegu, Daegu, Korea
Jong Hae Kim, Woon Seok Roh, Jin Yong Jung, Seok Young Song, Jung Eun Kim, and Baek Jin Kim
Peripheral nerve block has frequently been used as an alternative are situations in which spinal or epidural anesthesia cannot be to epidural analgesia for postoperative pain control in patients conducted, such as coagulation disturbances, sepsis, local undergoing total knee replacement. However, there are few reports infection, immune deficiency, severe spinal deformity, severe demonstrating that the combination of femoral and sciatic nerve blocks (FSNBs) can provide adequate analgesia and muscle decompensated hypovolemia and shock. Moreover, factors relaxation during total knee replacement. We experienced a case associated with technically difficult neuraxial blocks influence of successful FSNBs for a total knee replacement in a 66 year-old the anesthesiologist’s decision to perform the procedure [1]. In female patient who had a previous cancelled surgery due to a failed tracheal intubation followed by a difficult mask ventilation for 50 these cases, peripheral nerve block can provide a good solution minutes, 3 days before these blocks. FSNBs were performed with for operations on a lower extremity. The combination of 50 ml of 1.5% mepivacaine because she had conditions precluding femoral and sciatic nerve blocks (FSNBs) has frequently been neuraxial blocks including a long distance from the skin to the used for postoperative pain control after total knee replacement epidural space related to a high body mass index and nonpalpable lumbar spinous processes. This case suggests that FSNBs can [2]. However, there are few reports demonstrating that FSNBs provide a good alternative anesthetic method for total knee can provide an adequate anesthesia during a total knee replacement. (Anesth Pain Med 2011; 6: 270∼274) replacement. We experienced a case of successful FSNBs for a total knee replacement in a 66 year-old female patient who Key Words: Femoral nerve, Intubation, Nerve block, Sciatic nerve, had a history of failed tracheal intubation and conditions Total knee replacement. precluding neuraxial blocks.
CASE REPORT Spinal or epidural anesthesia has gained widespread acceptance for surgery involving the lower extremities. In the A 66 year-old female (height 150 cm, weight 84 kg) was presence of an increased risk of perioperative pulmonary scheduled for elective total knee replacement. She had been compromise, such as in patients with respiratory impairment or treated with methyprednisolone and methotrexate for degenerative features suggestive of a difficult airway after induction of osteoarthritis and rheumatoid arthritis for 3 years, and with general anesthesia, spinal or epidural anesthesia might confer antihypertensive medications including aspirin 100 mg once a some management and outcome advantages. On occasion, there day for hypertension for 5 years. One year ago, total knee replacement was canceled due to underlying conditions involving Received: February 21, 2011. heart and kidney, anemia and other problems in a local private Revised: March 4, 2011. Accepted: April 1, 2011. hospital and then she was transferred to our institution for Corresponding author: Woon Seok Roh, M.D., Department of better management of the problems. After appropriate management Anesthesiology and Pain Medicine, School of Medicine, Catholic of the clinical problems, an elective total knee replacement University of Daegu, 3056-6, Daemyeong 4-dong, Nam-gu, Daegu 705-718, Korea. Tel: 82-53-650-4504, Fax: 82-53-650-4517, E-mail: was scheduled. Preoperative laboratory tests showed hemoglobin [email protected] 8.5 g/dl, total white blood cell count 16,500 cells/mm3, platelet
270 Jong Hae Kim, et al：Peripheral nerve block and total knee replacement 271
Fig. 1. Preoperative chest radiograph shows mild pulmonary edema, left Fig. 3. Preoperative lumbar spine lateral radiograph demonstrates pleural effusion and destructive pulmonary tuberculosis in atelectasis distance from skin to epidural space is approximately 97.8 mm. involving left upper lobe.
block in electrocardiogram. However, the pulmonary function test revealed moderate obstructive lung defect with 0.93 liters of forced expiratory volume in one second and decrease in flow rate at peak flow and flow at 50% and 75% of the flow volume curve, and mild pulmonary edema, left pleural effusion and destructive pulmonary tuberculosis in atelectasis involving left upper lobe were visualized on preoperative chest radiograph (Fig. 1). She also had a history of dyspnea on exertion for 3 years. In addition, she came to be diagnosed with chronic renal failure due to hypertensive nephropathy during this admission. Examination of her upper airway revealed that soft palate and uvula were easily visualized and she was assigned to Mallampati class II. Flexion and extension of the cervical spine appeared to be reasonably well preserved. Her lumbar interspinous space could not be palpated due to excess body
Fig. 2. Preoperative lumbar spine anteroposterior radiograph shows trunk fat. She complained of intermittent low back pain, but osteophytes and no remarkably narrowed interlaminar space in the lower plain radiographs of the lumbar spine showed no particular lumbar vertebrae. bony abnormalities except osteophytes (Fig. 2 and 3). After reviewing the risks of the various forms of anesthesia, general count 106,000/mm3 and blood urea nitrogen 37.5 mg/dl, anesthesia was planned. creatinine 2.7 mg/dl, prothrombin time 11.9 seconds, activated Premedication consisted of intramuscular glycopyrrolate 0.1 partial thromboplatin time 34.4 seconds and bleeding time and mg 30 minutes before surgery. Electrocadiogram, pulse oxime- clotting time in the normal range. Pancytopenia resulting from try and blood pressure cuff were applied for intraoperative moni- disease modifying antirheumatic drugs was resolved following toring. Alveolar denitrogenation was performed with the patient their cessation, but the anemia still persisted. Preoperative vital breathing 100% oxygen through a nonrebreather mask. Anes- signs were blood pressure 120/80 mmHg and heart rate 60 thesia was induced with intravenous propofol 80 mg combined beats per minute. Transthoracic echocardiography and coronary with continuous infusion of remifentanil 0.3 μg/kg/min. After angiography were found to be normal with right bundle branch achieving unconsciousness, intravenous rocuronium 85 mg was 272 Anesth Pain Med Vol. 6, No. 3, 2011
Three days after the event, FSNBs was planned for the total knee replacement. On arrival in the operating room, monitoring
of noninvasive blood pressure, electrocardiogram and SpO2 was instituted. Then, femoral nerve block was performed lateral to the femoral artery immediately below the inguinal ligament. Successful location was indicated by contraction of the quadriceps femoris muscle with an initial current of 1 mA at 1 Hz and continuous contraction at 0.5 mA at 1 Hz using Ⓡ Stimuplex A 150 mm needle (Braun Medical, Melsungen, Germany). After negative aspiration, 25 ml of 1.5% mepiva- caine were injected. The sciatic nerve block was based on Fig. 4. This photograph shows the obese patient after femoral and sciatic Labat’s technique. In the lateral decubitus position (Sim’s nerve blocks. position), the same needle used for the femoral nerve block was inserted at a right angle to all cutaneous planes at administered. Suddenly, mask ventilation became impossible the caudal end of 3−5 cm line originating from, and and immediate endotracheal intubation was attempted. Laryngo- perpendicular to, the middle of a line that intersects the greater scopy revealed a grade 4 Cormack and Lehane view and trochanter posterior to the iliac spine. The sciatic nerve was another attempt of endotracheal intubation also failed. The identified with the help of a nerve stimulator using a stimulus consecutive attempts using a light wand, fiberoptic bronchoscope, of 1 mA at 1 Hz, while contractions of the gastrocnemius (foot laryngeal mask airway were in vain. However, saturation of plantar flexion) indicated proximity to the sciatic nerve and the peripheral oxygen (SpO2) was maintained above 95% with a needle was introduced until muscle twitches were elicited with two-handed technique despite failed intubation and difficult currents of 0.5 mA at 1 Hz. After negative aspiration, 25 ml positive pressure ventilation. After discussion of 20 minute-long of 1.5% mepivacaine were injected. Patients were then returned preoperative episodes with the surgeon, it was decided to to a supine position (Fig. 4). Radial artery catheterization and cancel the surgery. To reverse neuromuscular blockade, 20 mg subclavian central venous catheterization were performed for of pyridostigmine with 0.4 mg of glycoppyrolate was used continuous arterial pressure monitoring and central venous intravenously. Recovery of spontaneous respiration and conscious- pressure monitoring, respectively. The patient felt no pain at ness was not achieved in spite of 15 minutes of additional the incision site when pinch was applied just before the positive pressure ventilation with a two-hand technique, during operation. The operation had been uneventful since and took which arterial catheterization was instituted for continuous 150 minutes. After completion of the surgery, there were no blood pressure monitoring and frequent arterial blood sampling. postoperative complications, and laboratory data and vital signs At this time, the arterial blood gas analysis showed pH 7.14 were within normal limits. Until the next 2 hours after the
PaCO2 70 mmHg, PaO2 258 mmHg, and SaO2 100%. So, an surgery, she didn’t report the postoperative pain. The patient additional dose of reversal agent consisting of 10 mg of was discharged home 21 day after the surgery and reported no pyridostigmine and 0.2 mg of glycopyrrolate was injected complications related to the event. intravenously. A subsequent arterial blood gas measurement showed that ventilation had improved, with pH 7.30, PaCO2 DISCUSSION
45 mmHg, PaO2 492 mmHg and SaO2 100%. Ten minutes later, massive gastric distention resulting from excessive Regional anesthesia in total joint replacement is claimed to pressure applied to maintain airway was decompressed via a decrease the incidence of deep-vein thrombosis and pulmonary nasogastric tube. Gradually, she regained normal consciousness embolism and to reduce intraoperative bleeding, the need for and became responsive to verbal command. After taking a transfusion and the length of hospital stay. It can also increase portable chest x-ray film during one-hour stay in the recovery patient satisfaction especially after one-stage bilateral total hip room, the patient was moved to the ward and oxygen therapy replacement or total knee replacement [3]. Although spinal and was continued by Venturi mask. Her respiratory function had epidural anesthesia/analgesia may cause hypotension, motor completely recovered 2 hours after arriving on the ward. blockade, urinary retention, pruritus, inadvertent dural puncture Jong Hae Kim, et al：Peripheral nerve block and total knee replacement 273
palpation of the lumbar spinous processes, predicts difficulty of neuaxial block. Because the Mallampati score, most commonly used to assess the likelihood of a difficult laryngoscopy, does not successfully predict the difficulty in about 50% of patients [5], difficult intubation will continue to occur in an unpredictable fashion, like in this case (difficult laryngoscopy in spite of Mallampati score of 2). In the presence of the above factors that affect the safe conduct of neuraxial block and general anesthesia, FSNBs can be an excellent anesthetic option for patients undergoing total knee replacement. The unilateral sympathetic block resulting from FSNBs does not cause significant hemodynamic instability and the potential side effects of prolonged bilateral motor block or urinary retention, which result from neuraxial block. Moreover, FSNBs save time needed for the safe Fig. 5. Preoperative abdominopelvic computerized tomography scan positioning of the conscious patient and no time is required demonstrates distance from skin to epidural space is approximately 95.4 mm. for emergence in the operating room, when compared with general anesthesia. When long-acting agents are used, the block and neurological injury, which may make these techniques less provides initial postoperative analgesia, omitting the need for acceptable, epidural anesthesia/analgesia has been shown to opioids, which may make patients nauseated, thus limiting its improve the post-operative outcomes by relieving pain, use. These several benefits justify its use as an alternative reducing pulmonary complications, allowing early mobilization anesthesia for total knee replacement. and shortening the length of hospital stay. In this case, we The dose of mepivacaine used in this case (8.9 mg/kg), have chosen general anesthesia at first instead of spinal or which is more than maximum recommended dose (5−7 epidural anesthesia due to long distance from skin to epidural mg/kg), may cause systemic toxicity of local anesthetics. And space related to a high body mass index value and nonpalpable Kaiser et al. [6] reported that the mean maximum venous lumbar spinous processes. plasma concentration of mepivacaine was 5.1 μg/ml, which is No remarkably narrow interlaminar space in the lower the threshold for toxic symptoms (5−6 μg/ml), in a lumbar vertebrae visualized on the preoperative lumbar antero- pharmacokinetic study of "3-in-1"/sciatic nerve blocks for lower posterior radiograph (Fig. 2) indicates that rheumatoid arthritis limb surgery using 9.4 mg/kg of mepivacaine on the average. and osteoarthritis minimally affected the lumbar spine and However, the patient has some advantage over the systemic potential technical problems in the performance of neuraxial toxicity, because synthesis of the local anesthetic binding blockade might not be anticipated. However, it would be protein (alpha 1 acid glycoprotein) in the liver is stimulated in expected that the relatively long distance from skin to epidural renal failure, offering some protection against systemic toxicity space (approximately 9.5 cm) in the mid-lumbar area, which diminishing the free plasma fraction [7]. Actually, there were was roughly measured in the lateral X-ray film of the lumbar no signs and symptoms of systemic toxicity in the performance spine (Fig. 3) and abdominopelvic computed tomographic scan of FSNBs in this case. (Fig. 5) taken 6 months before the operation, could make In a previous study, the time lasting from the end of local neuraxial block difficult. This long distance seems due to a anesthetic injection to complete resolution of sensory and high body mass index value (37.33 kg/m2) according to the motor block in the patients receiving combined sciatic-femoral result of a previous study that has demonstrated correlations nerve block with 25 ml of 2% mepivacaine was 206 ± 51 between the depth of epidural space and body mass index [4]. minutes (values are expressed as mean ± standard deviation) In addition, inability to positively identify spinous process [8]. In this case, 900 mg of 1.5% mepivacaine were used could affect the decision not to perform neuaxial blockade in and there are no available reports comparable to the complete this patient as de Filho et al. [1] emphasized the quality of resolution time (approximately 270 minutes in this case) so patients’ anatomical landmarks, which was assessed by far. However, considering an increase in the volume and the 274 Anesth Pain Med Vol. 6, No. 3, 2011 concentration of local anesthetics produces a longer duration total knee replacement. of sensory block despite its not-linear pattern [9,10], a prolonged period of perioperative analgesia in this case is a REFERENCES consequent result. 1.de Filho GR, Gomes HP, da Fonseca MH, Hoffman JC, Several investigators have demonstrated that the femoral Pederneiras SG, Garcia JH. Predictors of successful neuraxial nerve block, to result in blockade of the femoral, obturator, block: A prospective study. Eur J Anaesthesiol 2002; 19: 447-51. and lateral femoral cutaneous nerves, does not consistently 2. Zaric D, Boysen K, Christiansen C, Christiansen J, Stephensen S, produce anesthesia of the obturator nerve [11] and addition of Christensen B. A comparison of epidural analgesia with combined obturator nerve blocks improves postoperative analgesia [12]. continuous femoral-sciatic nerve blocks after total knee replacement. Anesth Analg 2006; 102: 1240-6. However, an additional obturator nerve block could not be 3. Schafer M, Elke R,Young JR, Gancs P, Kindler CH. Safety of performed because the dose of local anesthetic used in FSNBs one-stage bilateral hip and knee arthroplasties under regional was already over maximum recommended dose. Fortunately, the anaesthesia and routine anaesthetic monitoring. J Bone Joint Surg quality of surgical anesthesia in this case was enough for the Br 2005; 87: 1134-9. patient to undergo the total knee replacement, presumably due 4. Hoffmann VL, Vercauteren MP, Buczkowski PW, Vanspringel GL. A new combined spinal-epidural apparatus: measurement of to occasional proximal spread of local anesthetics to the the distance to the epidural and subarachnoid spaces. Anaesthesia obturator nerve or no cutaneous contribution of the obturator 1997; 52: 350-5. nerve [13]. 5. Wilson ME. Predicting difficult intubation. Br J Anaesth 1993; 71: Recently, introduction of ultrasound imaging techniques to 333-4. peripheral nerve blocks decreases the dose of local anesthetics 6. Kaiser H, Niesel HC, Biscoping J, al-Rafai S, Klimpel L. Plasma required to produce a successful surgical block and time to prilocaine and mepivacaine concentrations after combined lumbosacral plexus block. Acta Anaesthesiol Scand 1992; 36: perform the procedures, and provides improvements in onset 689-91. and success of sensory block. Nevertheless, nerve stimulation 7. Svensson CK, Woodruff MN, Baxter JG, Lalka D. Free drug should be an essential part of ultrasound guided technique, as concentration monitoring in clinical practice. rationale and current ultrasound alone only had a 60% success rate [14]. Furthermore, status. Clin Pharmacokinet 1986; 11: 450-69. ultrasound-aided peripheral nerve stimulated block is perhaps 8. Casati A, Cappelleri G, Fanelli G, Borghi B, Anelati D, Berti M, et al. Regional anaesthesia for outpatient knee arthroscopy: a the optimal way to achieve a successful block, especially at randomized clinical comparison of two different anaesthetic the beginning of a learning process [15]. Thus, unavailability techniques. Acta Anaesthesiol Scand 2000; 44: 543-7. of ultrasound at the time of FSNBs implies the limitation of 9. Concepcion M, Arthur GR, Steele SM, Bader AM, Covino BG. our experience. By decreasing the dose of local anesthetics A new local anesthetic, ropivacaine. its epidural effects in humans. required for FSNBs under ultrasound guidance, it should have Anesth Analg 1990; 70: 80-5. been possible to perform an additional obturator block, which 10. Chambers WA, Littlewood DG, Edstrom HH, Scott DB. Spinal anaesthesia with hyperbaric bupivacaine: Effects of concentration could not be blocked consistently by femoral 3 in 1 block. and volume administered. Br J Anaesth 1982; 54: 75-80. This case shows that FSNBs offers beneficial alternative 11. Lang SA, Yip RW, Chang PC, Gerard MA. The femoral 3-in-1 anesthesia in a total knee replacement for a patient who has a block revisited. J Clin Anesth 1993; 5: 292-6. previous history of unexpected failed endotracheal intubation 12. Macalou D, Trueck S, Meuret P, Heck M, Vial F, Ouologuem S, and factors precluding central neuraxial block. The increase in et al. Postoperative analgesia after total knee replacement: the degenerative diseases deforming spinal anatomy and cardio- effect of an obturator nerve block added to the femoral 3-in-1 nerve block. Anesth Analg 2004; 99: 251-4. vascular disease requiring antiplatelet therapy is accompanied 13. Bouaziz H, Vial F, Jochum D, Macalou D, Heck M, Meuret P, by the rapid rise in the elderly population. And the prevalence et al. An evaluation of the cutaneous distribution after obturator of obesity is also increasing dramatically in developed nerve block. Anesth Analg 2002; 94: 445-9. countries. Currently, no test is specific or sensitive enough to 14. Yang WT, Chui PT, Metreweli C. Anatomy of the normal brachial predict all difficult intubations. These conditions, that prevent plexus revealed by sonography and the role of sonographic guidance in anesthesia of the brachial plexus. AJR Am J the safe conduct of neuraxial block and general anesthesia, Roentgenol 1998; 171: 1631-6. result in the need of an alternative anesthetic technique. In 15. Orebaugh SL, Williams BA, Kentor ML. Ultrasound guidance with conclusion, FSNBs can be one of the good alternatives to nerve stimulation reduces the time necessary for resident peripheral neuraxial block and general anesthesia for patients undergoing nerve blockade. Reg Anesth Pain Med 2007; 32: 448-54.