A Combination of Ultrasound-guided Popliteal Sciatic Nerve Block and Adductor Canal Block as a Sole Anaesthetic Technique for below Knee Amputation in High-risk Patients: A Case Series

Abstract

Below-knee amputation in high-risk patients is associated with significant mortality and morbidity. Spinal anaesthesia is linked to an increased incidence of hypotension and bradycardia, and it is relatively contraindicated in patients with coagulation abnormalities. General anaesthesia is used as an alternative when spinal anaesthesia is contraindicated, but it is associated with a considerable increase in perioperative morbidity and the need for postoperative ventilatory support and Intensive Care Unit (ICU) care. A combination of sciatic nerve block and femoral block has been employed for below-knee surgeries as it provides complete anaesthesia below the knee. Adductor canal block, compared to femoral nerve block, is motor-sparing and, when combined with popliteal sciatic nerve block, offers complete anaesthesia below the knee. Below-knee amputation requires complete motor and sensory blockage, making regional block for below-knee amputation more challenging for the anaesthesiologist. Present case series is of five cases of below-knee amputation performed under a combination of ultrasound-guided popliteal sciatic nerve block and adductor canal block. Ultrasound-guided popliteal sciatic nerve block was administered with a combination of 10 mL of bupivacaine 0.5% and 5 mL of lignocaine 2% with adrenaline (1:200,000) diluted with 5 mL of distilled water to a total volume of 20 mL. Ultrasound-guided adductor canal block was performed with 8 mL of bupivacaine 0.5% and 4 mL of lignocaine 2% with adrenaline (1:200,000), diluted with 4 mL of distilled water to a total volume of 16 mL. All patients achieved adequate surgical anaesthesia, and none experienced any anaesthesia-related complications.