A comparative study between dexmedetomidine and dexamethasone as adjuvants to bupivacaine in ultrasound guided interscalene block for arthroscopic shoulder surgery

Abstract

Background & Objectives: Arthroscopic surgery is a preferred approach for shoulder surgeries due to its documented advantages of early postoperative recovery. However, postoperative pain remains a concern for which different techniques are used. Interscalene block (ISB), using dexmedetomidine (DXM) or dexamethasone (DXA) as adjuvants to local anesthetics (LA), is a common analgesic method. We conducted this comparative study to establish if any one of the adjuvants is better in terms of postoperative analgesia.

Methodology: Patients undergoing shoulder arthroscopy were assigned randomly to three groups: Group A (LA alone), Group B (ISB with DXM), and Group C (ISB with DXA). Assessment of intraoperative and postoperative hemodynamics, visual analog scale (VAS) pain scores, time to first rescue analgesic, and rescue analgesic (ketorolac) consumption were recorded.

Results: Intraoperative and postoperative heart rate and mean arterial pressure showed no significant differences among the three groups, suggesting comparable hemodynamic control. VAS pain scores were equivalent at 1, 2 and 6 h postoperatively, but at 12, 18 and 24 h, Groups B and C demonstrated significantly lower scores compared to Group A (P < 0.001). Time to first rescue analgesic was prolonged in Groups B and C, indicating improved and longer-lasting analgesia. Groups B and C consumed considerably less ketorolac overall than Group A (P < 0.001).

Conclusion: While all three groups exhibited equivalent intraoperative and postoperative hemodynamic control, the addition of dexmedetomidine or dexamethasone to local anesthetics for interscalene block prolonged postoperative analgesia, reduced pain scores at 12, 18 and 24 h, delayed time to first rescue, and decreased total analgesic consumption. Both adjuvants showed advantages over local anesthetics alone, emphasizing their potential in multimodal analgesia for shoulder arthroscopy.

Abbreviations: ISB - Interscalene block; DXM - Dexmedetomidine; DXA - Dexamethasone; HR – Heart Rate; MAP – Mean Arterial Pressure; VAS Visual Analog Scale.

Trial registry: PACTR202210507488378

Keywords: Analgesia; Analgesia, postoperative; Dexmedetomidine; Dexamethasone; Interscalene block; Pain, postoperative; Shoulder arthroscopy

Citation: Nashaat P, Mohamed O, George S, Mohammed A, Samy E. A comparative study between dexmedetomidine and dexamethasone as adjuvants to bupivacaine in ultrasound guided interscalene block for arthroscopic shoulder surgery. Anaesth. pain intensive care 2024;28(5):850−858; DOI: 10.35975/apic.v28i5.2566

Received: June 13, 2024; Reviewed: June 20, 2024; Accepted: July 18, 2024