The effect of warming ropivacaine on ultrasound-guided subgluteal sciatic nerve block: a randomized controlled trial

Abstract

Abstract Background Currently, no information is available on the influence of local anaesthetics at different temperatures on sciatic nerve block. This study aims to determine whether warming ropivacaine has an influence on the onset of subgluteal sciatic nerve block under the ultrasonic guidance . Methods Fifty-four patients with distal lower limbs surgery were randomly allocated into warming group (group W, n = 27 ) or room tempeture gruop (group R, n = 27 ). A sciatic nerve block with subgluteal approach under ultrasound guidance was performed with either 30 ml of 0.5% ropivacaine at a temperature of 23℃for group R or 30 ml of 0.5% ropivacaine at a temperature of 30℃for group W. The sensory and motor blockade were assessed every 2 minutes over a 30-minute period following injection.The primary outcome was the onset of limb sensory block . Results In comparison with the group R, the time to onset of motor and sensory block in group W was significantly reduced. No obvious differences for the satisfaction of patients and duration of anesthesia were discovered between both groups. No complications associated with nerve block were observed 2 days after surgery. Conclusions Warming ropivacaine 0.5% to 30℃ received a significantly faster onset of anesthesia during subgluteal sciatic nerve block. Trial registration The trial was registered on October 3, 2022 in the Chinese Clinical Trial Registry (https://www.chictr.org.cn/bin/project/edit?pid=181104), registration number ChiCTR2200064350.(03/10/2022).