Efficacy of intra-articular dexmedetomidine for postoperative analgesia in arthroscopic knee surgery

INTRODUCTION: Various drugs are administered intraarticularly to provide postoperative analgesia after arthroscopic knee surgery, of which opioids and alpha2 agonists could be of particular interest. METHODS: Sixty patients undergoing elective knee arthroscopy were randomly assigned to two groups (n = 30). Group R received 19 ml of 0.25% ropivacaine and 1 ml of isotonic saline (total volume 20 ml) intraarticularly. Group RD received 100 microg (1 ml) of dexmedetomidine added to 19 ml of 0.25% ropivacaine intra-articularly (total volume 20 ml). Analgesic effect was evaluated by measuring pain intensity (VAS score) and duration of analgesia. RESULTS: A longer delay was observed between intraarticular injection of study medication and first requirement of supplementary analgesic in group RD (10.84 +/- 2.6 hours) compared to group R (5.38 +/- 1.4 hours). Total consumption of fentanyl citrate in postoperative period was significantly less in group RD. No significant side effects were noted. CONCLUSION: Dexmedetomidine, added as adjunct to ropivacaine in patients undergoing arthroscopic knee surgery, improve the quality and duration of postoperative analgesia.