Background: Dexmedetomidine is an alpha-2 agonist with sedative and analgesic properties. This study compared the postoperative analgesic effects of intra-articular dexmedetomidine with those of bupivacaine and saline.
Materials and Methods: After Ethics committee approval, 51 patients scheduled for arthroscopic meniscal surgery were randomized in a double blind fashion to receive either dexmedetomidine 1 μg kg-1 (group D), bupivacaine 0.25% (group B), or saline (group S) intraarticularly (total volume 20 ml). All patients received a standardized general anesthetic with propofol, fentanyl, and sevflurane. Postoperatively, acetaminophen 500mg/codeine 30mg oral tablet was given every four hours, and tramadol 1 mg kg -1 IV was administered every 6 hours, as needed, for rescue analgesia. Visual analogue scale (VAS) scores (0-10), time to first analgesic request, and the total dose of post-operative analgesics were recorded. Repeated measures ANOVA were used to analyse VAS scores, whereas ANOVA was used to assess the other variables. Data presented as mean±SD and significance was defined as p < 0.01.
Results and Discussion: VAS scores were lower in groups D and B compared with group S (P < 0.01). Times to first analgesic were 343±27 vs.440±3 vs. 43±5 min for groups D, B, and S, respectively (P < 0.01). Total dose of rescue tramadol were 180±56 vs. 160±51 vs. 413±52 mg, respectively (P< 0.01).
Conclusion: Intraarticular dexmedetomidine provided comparable analgesia to bupivacaine 0.25% in patients undergoing arthroscopic knee surgery.