Efficacy of Sciatic Nerve Block for Pain Management in below Knee Orthopaedic Surgery.

INTRODUCTION: Perioperative pain management is an integral part of anaesthesia and patients are most satisfied if there is minimal or no pain after surgery. Sciatic nerve block provides postoperative pain relief after below knee surgery and knee surgery. Many studies with different approaches for sciatic nerve block have been conducted to demonstrate the efficacy of sciatic nerve block with different local anaesthetic drugs over the past decade.

AIM: To study the efficacy of single-shot sciatic nerve block for postoperative pain management in below knee orthopaedic surgery.

MATERIALS AND METHODS: Sixty patients of American Society of Anaesthesiologists (ASA) grade I and II aged 18 to 60 years of either sex (male or female) scheduled for unilateral below knee open orthopaedic surgery under spinal anaesthesia and ready to participate in this study were included. Sciatic nerve block with Bupivacaine was given by classic (posterior) approach of Labat using peripheral nerve stimulator and /or ultra sound. Intraoperatively heart rate, noninvasive mean BP, respiratory rate, ECG, SpO2 was monitored. Pain was assessed using "Visual Analogue Scale" (VAS) postoperatively. Diclofenac sodium was given as rescue analgesia when VAS was > 3. Time of supplemental analgesia was noted.

RESULTS: Mean VAS was maximum at 18 hours, 16 (26.7%) patients did not require any rescue analgesia, whereas 93.4% patients did not require rescue analgesia upto 18 hours after surgery. Mean VAS score of the patients who did not require rescue analgesia was 2.06 at 24 hours postoperatively which is far below the level where rescue analgesia was required. The mean time by which rescue analgesia was given was 19.3 hours with standard deviation of ± 3 hours. Inj. diclofenac sodium 75 mg was given intravenously as rescue analgesia when VAS score exceeded 3. No adverse systemic toxicity of Bupivacaine was observed within 24 hours after the operation.

CONCLUSION: Single shot sciatic nerve block provided effective pain relief to majority of the patients upto 18 hours in below knee orthopaedic surgery and also decreased analgesic drugs requirement postoperatively. Sciatic nerve block was safe with no adverse effects.