Use of hyaluronidase as an adjuvant to ropivacaine to reduce axillary brachial plexus block onset time: a prospective, randomised controlled study.

Abstract

When considering brachial plexus block as a practical alternative to general anaesthesia for upper limb surgery, the time to achieve complete sensory block is a clinically important variable. In this prospective randomised double-blind controlled trial, we investigated the hypothesis that addition of hyaluronidase to ropivacaine may reduce the time to achieve complete sensory block after axillary brachial plexus block. The patients were randomly assigned into a hyaluronidase group (n=24) and a control group (n=24). The hyaluronidase group received ropivacaine 0.5% with 100IU.ml(-1) of hyaluronidase, and the control group received ropivacaine alone. The primary endpoint was the time to achieve complete sensory block. The hyaluronidase group demonstrated significantly shorter mean (SD) sensory block onset time (13.8 (6.0) min) compared with the control group (22.5 (6.3)min, p<0.0001). Addition of hyaluronidase to ropivacaine resulted in a reduction in the time needed to achieve complete sensory block.