The Effect of Clonidine on Lidocaine Induced Supraclavicular Brachial Plexus Block

Abstract

BACKGROUND: Brachial plexus nerve blocks (BPB) are the most common nerve blocks used for upper limb surgeries. Techniques using only Local Anaesthetics (LA) have limited duration of post-operative analgesia. Clonidine has been used to prolong the duration of LA s for neuraxial blocks. Hence the effect of clonidine on Lidocaine induced BPB was studied. METHODS: 60 patients of American Society of Anesthesiologists (ASA) class I and II were randomly divided into 2 groups. Group L given 30 ml of Lidocaine with adrenaline 1.5% with 0.6 ml of normal saline and the Group C given 30 ml of same LA with 0.6 ml of 90mcg of Clonidine. All the patients' supraclavicular BPB was given using Winnies' peri-vascular approach. The primary outcome was onset, duration of sensory and motor blockade. The secondary outcomes were motor block duration, opioid supplementation, and BPB complication. RESULTS: There was no statistically significant difference in the onset of sensory and motor block, motor blockade quality and overall quality of block. Duration of sensory and motor blockade was prolonged in groups with Clonidine. No adverse events / hemodynamic instability noted in either group. Sedation scores were higher in Clonidine group. No patients required any intervention. CONCLUSIONS: 90µg Clonidine added to Lidocaine 1.5% with adrenaline produces prolongation of both the duration of sensory and motor blockade with minimal adverse effects.