Efficacy of intra-articular dexmedetomidine for postoperative analgesia in arthroscopic knee surgery done under spinal anesthesia

Abstract

Background: Postoperative pain is a common and distressing symptom after knee arthroscopy. This study aims at analyzing the efficacy of intra-articular dexmedetomidine for postoperative pain relief in patients undergoing arthroscopic knee procedures under unilateral spinal anesthesia. Materials and Methods: Fifty adult patients of American Society of Anaesthesiologists Class 1-2, aged 20-60 years posted for arthroscopic knee surgery were randomly divided into Groups I (control group) and II (dexmedetomidine group) with 25 patients in each group. Anesthetic technique used was unilateral spinal in all the patients. Group I was the control group and Group II the dexmedetomidine group. Group II patients received 1 μg/kg dexmedetomidine diluted to 20 ml in normal saline via intra-articular route at the end of the procedure and Group I patients received an equal volume of normal saline. Visual analog scale (VAS) score for 24 h, time to give the first dose of analgesia and total dose of analgesic required in each group was evaluated. Results: VAS scores were significantly lower in Group II, time to first analgesic requirement was significantly greater in Group II (308 ± 3.59) than in Group I (244 ± 2.92), P < 0.001 and total dose of analgesic used in Group II (36 mg ± 7.65) patients was significantly lesser compared to patients in Group I (129 mg ± 6.87), P < 0.001. Conclusion: Intra-articular dexmedetomidine is effective in providing prolonged postoperative analgesia after arthroscopic knee procedures and reduces the total dose of analgesic required postoperatively.