Intra-articular versus intravenous administration of dexmedetomidine in arthroscopic knee surgeries under local anesthesia: A prospective randomized study

Background: An intra-articular injection is considered the leading method for postoperative analgesia after knee surgery. Dexmedetomidine has peripheral and central analgesic effect. The study was conducted to compare between the analgesic effect of intra-articular and intravenous dexmedetomidine in arthroscopic knee surgery. Methods: One hundred patients underwent elective arthroscopic knee surgery had randomly allocated into two equal groups. (Group IA) the patients had received 1 µg/kg dexmedetomidine added to local anesthetic bupivacaine intra-articularly while (Group IV): the patients had received 1 µg/kg dexmedetomidine added to 20 ml saline over 10 min starting with local intra-articular anaesthesia. Pain VAS, heart rate, mean arterial blood pressure, total requirement for analgesic, the first request for it, and first time to mobilize within the first 24 h were assessed. Results: The VAS were significantly lower in IA group at 4 and 6 h during rest and at 4, 6, 12 h during motion, Also, the duration of first analgesic request was significantly prolonged in IA group than IV group (11 h ± 2.2 vs 9.2 h ± 3.2, respectively) (p value .001). Moreover, the total analgesic consumption was significantly lesser IA group compared with that in IV group (87 ± 27.7 mg Vs 108 ± 37.6 mg, respectively) (p value .002). No postoperative adverse effects were recorded. Conclusion: Intra-articular dexmedetomidine when added to local anaesthesia improves the postoperative analgesic profile with decrease the needs for postoperative analgesia and prolong the time for analgesic request. Clinical trial registration: NCT02730845