A controlled randomized clinical trial of the efficacy and safety of hyaluronidase as an adjuvant to bupivacaine in ultrasound-guided supraclavicular brachial plexus block

Background and aim Several adjuvants are used with local anesthetics in regional blocks such as supraclavicular brachial plexus block. The goal of this combination is to increase the anesthetic duration. Hyaluronidase enzymes act by increasing tissue permeability by catalyzing the breakdown of the intercellular matrix and diffusion of pharmacological agents. We aimed to examine the effect of hyaluronidase on the safety and efficacy of bupivacaine in ultrasound-guided supraclavicular brachial plexus block. Patients and methods A prospective, randomized, controlled, double-blinded study was conducted at Al-Azhar University Hospitals (Assiut) for patients scheduled for elective surgery of the upper limb. Sixty patients of three equal groups: group I received bupivacaine 0.5% plus 5ml 0.9% normal saline. Group II received 0.5% bupivacaine plus 5ml 0.9% normal saline containing 500 IU hyaluronidase. Group III received bupivacaine 0.5% plus 5 ml 0.9% normal saline containing 250 IU hyaluronidase. Results The onset of sensory and motor block was significantly lower in groups II and III compared to group I. The duration of sensory block and motor block were insignificantly different among the three groups. Visual analog scale was insignificantly different at the beginning and end of the study duration. The heart rate was insignificantly different at the beginning and end of the study duration. Horner’s syndrome was insignificantly different among the three groups. Conclusion The use of 500 and 250 IU hyaluronidase reduced the time to achieve complete sensory and motor block and pain score compared to bupivacaine only with superiority of 500 IU dose.