A Comparative Study of Adjuvants (Dexmedetomidine Vs Dexamethasone) to Ropivacaine in Supraclavicular Brachial Plexus Block for Onset and Duration of Sensory Analgesia

BACKGROUND : Enhancing the duration of sensory and motor blockade of regional anaesthesia is often desirable for prolonged surgeries and also provides pain relief in the immediate postoperative period. We performed a prospective, randomised, study to evaluate the effect of Dexmedetomidine and Dexamethasone as adjuvants to Ropivacaine in supraclavicular approach of brachial plexus block. METHODS:Sixty ASA physical status 1 and 2 patients undergoing elective hand , forearm and elbow surgeries under brachial plexus block were randomly divided to receive either 8 mg Dexamethasone (1ml) + 30 ml 0.75% Ropivacaine + 1ml distilled water or 50 mcg Dexmedetomidine (o.5ml) + 30 ml 0.75% Ropivacaine + 1.5 ml distilled water. The block was performed using a nerve stimulator. Onset and duration of sensory and motor blockade and total duration of analgesia were measured. Vitals were recorded at 3,5,10,15,30 and 45 minutes. RESULTS: The onset of sensory block and onset of motor block both were found to be sooner with Dexmedetomidine than Dexamethasone. The duration of sensory block and motor blockade and duration of analgesia was longer with Dexmedetomidine than Dexamethasone. CONCLUSION: Both Dexmedetomidine and Dexamethasone enhanced the onset and duration of blockade but, the effect was found to be more pronounced with Dexmedetomidine.