comparison of ultrasound guided popliteal sciatic nerve block through lateral and posterior approach for below knee surgeries - A randomized comparative study

INTERVENTION: Intervention1: Popliteal sciatic nerve block under ultrasound guidance‐lateral approach: 0.5% bupivacaine 20ml(100mg) in Popliteal sciatic nerve block under ultrasound guidance‐lateral approach for below knee surgeries. Control Intervention1: Popliteal sciatic nerve block under ultrasound guidance‐posterior approach: 0.5% bupivacaine 20ml (100mg) Popliteal sciatic nerve block under ultrasound guidance‐posterior approach for below knee surgeries. CONDITION: Health Condition 1: O‐ Medical and Surgical PRIMARY OUTCOME: To compare the sciatic nerve visibility score among popliteal sciatic nerve block patients in lateral and posterior approach under ultrasound guidance.Timepoint: Sciatic nerve visibility will be assessed after giving the popliteal block under USG guidance by standard asssessors using the saved USG image of popliteal sciatic nerve ‐ baseline . ; Sensory and motor block will be assessed at baseline ,5minutes once ,half an hour once for 6hrs. SECONDARY OUTCOME: 1.To compare performers ease score among popliteal sciatic nerve block patients in lateral and posterior approach under ultrasound guidance. ; 2.To compare the block success rate among popliteal sciatic nerve block patients in lateral and posterior approach under ultrasound guidance.Timepoint: Onset of motor and sensory block was assessed every 5 minutes once for 1st 30 minutes. INCLUSION CRITERIA: Patients of ASA physical status 1 & 2