Comparison of Dexmedetomidine and Fentanyl as an Adjuvant to Ropivacaine in Ultrasoundguided Supraclavicular Brachial Plexus Block: A Prospective Observational Study

Introduction: Upper limb surgeries are mostly performed under supraclavicular brachial plexus blocks which provide intraoperative and postoperative analgesia. Ultrasound provides clinicians with real-time images which are useful for better identification of the anatomical structures, safe needle placement, and adequate local anaesthetic spread. Adding adjuvants to local anaesthetic drugs prolong the duration of anaesthesia without concomitantly increasing the risk of complication.

Aim: To compare fentanyl and dexmedetomidine when added as an adjuvant to ropivacaine for Ultrasound-guided supraclavicular brachial plexus block.

Materials and Methods: A prospective observational, double-blinded study was conducted in the Department of Anaesthesia, at Government Medical College, Kottayam, Kerala, India, on 52 patients undergoing orthopaedic upper limb surgeries over a period of one year from April 2019-March 2020. Patients were divided into two groups of 26 subjects each. Group A received ropivacaine 0.5% (20 mL)+dexmedetomidine 1 mcg/kg and group B received ropivacaine 0.5% (20 mL)+Fentanyl 1 mcg/kg. Onset, time to complete sensory and motor block, duration of sensory and motor block, duration of analgesia, adverse effects and haemodynamic status were monitored. Statistical analysis was done using t-test and Chi-square test.

Results: The demographic variables, onset of sensory and motor block were comparable in both the groups. Mean duration of sensory block in group A and B were 638.08±52.001 minutes and 568.85±36.478 minutes respectively. The mean duration of motor block in group A was 605.77±58.8 minutes and group B was 513.46±14.982 minutes. The mean duration of analgesia in group A and B were 722.3±58.13 and 615.00±48.19 minutes, respectively. Mean duration of sensory block, motor block and analgesia were found more in group A which was statistically significant with p-value=<0.05. There was no significant difference in haemodynamic parameters.

Conclusion: Dexmedetomidine was a better adjuvant to 0.5% ropivacaine as compared to fentanyl in Ultrasound-guided supraclavicular brachial plexus block in terms of duration of sensory block, motor block and analgesia.