A clinical study of effects of clonidine as adjuvant with ropivacaine in ultrasound guided axillary brachial plexus block

Abstract

Background: Axillary Brachial plexus block is the distal block performed on the brachial plexus. With the advent of ultrasound guidance establishing the blockade has been easier with reduced drug dosage and less complications. Objective: To evaluate and compare the effects of addition of clonidine with ropivacaine for axillary block with reference to a) onset of sensory blockade b) onset of motor blockade c) duration of analgesia. Methods: 60 patients of ASA class 1& 2 for upper limb surgical procedures were randomly allocated into two groups of 30 each, Group P will receive ropivacaine 0.75% 20ml + NaCl 0.9% (0.5ml) Group D will receive ropivacaine 0.75% 20ml + clonidine 75µg (0.5ml). With ultrasound guidance axillary brachial plexus block was administered. Testing for onset of sensory blockade was done using pin prick method, Motor block was assessed using modified Bromage scale, Post operatively patients would be assessed for the duration of sensory and motor blockade. Results: The present study shows that 20 ml of 0.75% Ropivacaine with clonidine 75 mcg prolonged the duration of motor, sensory block and duration of analgesia when compared with 20 ml of 0.75% Ropivacaine with NaCl 0.9% .The onset of sensory, motor blocks was significantly faster with 0.75% Ropivacaine with clonidine 75 mcg group (Group D) when compared with 0.75% Ropivacaine with NaCl 0.9% group (Group P). Conclusion: Clonidine 75 µg as an adjuvant to 0.75% ropivacaine produces satisfactory onset of sensory and motor blockade, with increased duration of analgesia when used for axillary brachial plexus block under ultrasound guidance without any adverse effects.