A double blind randomized study to assess the addition of clonidine to ropivacaine in supraclavicular brachial plexus block

Background: The supraclavicular brachial plexus block provides anesthesia of the entire upper extremity in consistent and time-efficient manner. Ropivacaine is an amide, local anaesthetic agent, eliciting nerve block in brachial plexus. Clonidine as an adjuvant to ropivacaine enhances the quality and duration of analgesia when given epidurally or intrathecally. The aim of the present study was to assess the effect of adding clonidine to ropivacaine in supraclavicular brachial plexus block.Methods: Sixty patients were randomly divided into two groups, Group C and R. Group C received 0.5% of ropivacaine with 1 ml normal saline while Group R received same amount of ropivacaine with 1 ml (equivalent to 100μg) of clonidine for supraclavicular brachial plexus block. The groups were compared regarding quality of sensory and motor blockade, duration of post-operative analgesia, intra and post-operative hemodynamic changes and sedation scores.Results: There was a significant increase in duration of sensory and motor block and duration of analgesia in Group C as compared to Group R (P<0.001). There was no significant difference in mean onset time for sensory and motor blockade, the hemodynamic parameters (pulse rate, diastolic and systolic blood pressure)during and after surgery, sedation score post operatively in either groups (P>0.05).Conclusions: Clonidine 100µg added to 0.5% ropivacaine for supraclavicular brachial plexus block, does not shorten the onset of sensory and motor blockade but the combination produced prolonged sensory and motor blockade, improved and prolonged duration of analgesia, thereby decreasing the need for systemic analgesics without any hemodynamic changes.