A comparative study of the analgesic effect between ropivacaine alone and ropivacaine with clonidine through supraclavicular brachial plexus block in upper limb surgical procedures

Abstract

Background: Peripheral nerve blockade has become an essential and growing part of anaesthesia. Only few studies are available regarding use of ropivacaine with adjuvant clonidine for modification of block but with equivocal results. Hence the present study was planned to evaluate the effect of adding clonidine to ropivacaine in supraclavicular plexus blockade for upper limb surgical procedure.
Materials & Methods: This prospective randomized single blind placebo controlled clinical study was done in a tertiary medical college, Kolkata between Jan 2012 and July 2013. Patients of either sex of ASA physical status I or II age groups 18-65 years undergoing elective upper limb surgery under supraclavicular brachial plexus block. This study was designed to conduct for prolonging the duration of postoperative analgesia with 25 ml 0.75% ropivacaine along with 30µgm clonidine and 25 ml 0.75% ropivacaine in two groups of patients subjected for upper limb surgery.  Two groups were compared for duration of analgesia, onset and duration of sensory and motor blockade. It also studied hemodynamics changes and adverse effects. The degree of sedation was evaluated by using the University of Michigan Sedation Scale [UMSS of o to 4].
Results: The duration of sensory block was 9.2±0.21 hrs and 6.1±0.17 hrs respectively in group 1 and group 2 (p<0.001). All the patients in group 1 and 2 requiring rescue analgesic were 10.1±0.17 and 7±0.13 respectively. Thus, ropivacaine with clonidine provided earlier onset and peak of sensory effect with comparable duration of post operative analgesia when compared to ropivacaine with normal saline.  The mean onset time of motor block was 10.9±0.56 min and 10.8±0.41 min (p<0.51) and duration of 8.1±0.21 hrs and 5.1±0.15 hrs (p<0.001) in group 1 and group 2 respectively.
Conclusion: Thus, ropivacaine with clonidine gave long time of blockade in duration of sensory and motor blockade and also in time requiring for the rescue analgesia by giving injection tramadol.