Clonidine as an Adjuvant to Local Anaesthetic in Infraclavicular Brachial Plexus Block: A Randomised Clinical Trial

Introduction: Brachial plexus blocks are routinely performed to provide anaesthesia and analgesia for upper limb orthopaedic surgeries. Various adjuvants are being added to local anaesthetic solution to prolong the duration of sensory and motor blockade to ensure successful completion of long duration surgeries with adequate postoperative analgesia. Clonidine is used in varying dosages as adjuvant for peripheral nerve block.

Aim: To study different dosages of clonidine when used as an adjuvant in infraclavicular approach to brachial plexus block.

Materials and Methods: The randomised double-blind clinical study enrolled 60 American Society of Anaesthesiologists (ASA) I and II patients, between ages of 18-60 years, undergoing elective forearm orthopaedic surgery, lasting more than one hour. Based on the dose of clonidine added, the patients were distributed to group I (75 μg); group II (100 μg) and group III (150 μg). They were compared with regard to onset and duration of sensory and motor blockade, haemodynamic parameters, quality of sedation and side-effects. The results were analysed using Statistical Package for the Social Sciences (SPSS) version 21.0.

Results: Demographic profile was comparable between the study groups. The onset of sensory and motor duration was faster in group III (5.8±1.65 minutes; 10.08±0.98 minutes). Also, the duration of sensory and motor blockade was highest in group III (11.02±2.33 hours; 10.44±1.45 hours). Patients in group III had significantly higher level of sedation in comparison to other groups.

Conclusion: Clonidine in a dose of 150 μg provides significantly longer duration of sensory and motor blockade without any adverse haemodynamic outcomes.