LATENCY OF BRACHIAL-PLEXUS BLOCK - THE EFFECT ON ONSET TIME OF WARMING LOCAL-ANESTHETIC SOLUTIONS

A double‐blind study was set up to investigate the effect of warming local anaesthetic solutions on the latency of onset of subclavian perivascular brachial plexus blocks. Twenty‐four adult patients were randomly allocated into two equal groups. In group A the local anaesthetic was injected at room temperature, while in group B the local anaesthetic solution was prewarmed to 37°C in a thermostatically controlled heating block. All blocks were performed using 0.5 ml/kg of a solution prepared by mixing equal volumes of 0.5% bupivacaine with adrenaline 1:200 000, and 1% prilocaine. The speed of onset of sensory blockade was significantly increased when the temperature of the local anaesthetic solution was increased to 37°C. There were no adverse side effects in either group. Copyright © 1990, Wiley Blackwell. All rights reserved