Dexamethasone and Dexmedetomidine as an Adjuvant to Intraarticular Bupivacaine for Postoperative Pain Relief in Knee Arthroscopic Surgery: A Randomized Trial

Background: Knee arthroscopy causes minimal trauma, however, good analgesia is required forearly rehabilitation and return to normal life in the patients.Objective: We aimed to compare the analgesic effects of intraarticular dexamethasone anddexmedetomidine added to bupivacaine with those of bupivacaine alone.Study Design: This study uses a double-blind, randomized, controlled design with allocationconcealment in a 3-armed parallel group format among patients undergoing arthroscopic meniscalsurgery.Setting: The study was conducted at Assiut University Hospital in Asyut, Egypt. The study durationwas from July 2016 to February 2017.Methods: After the ethics committee approval, 60 patients, with the American Society ofAnesthesiologists (ASA) physical status of I or II, 20 – 50 years old, and scheduled for arthroscopicmeniscal surgery were randomized in a double-blind manner to receive 18mL intraarticularbupivacaine 0.25% with either dexamethasone 8 mg (group I), dexmedetomidine 1 μg/kg (groupII), or 2 mL of normal saline (group III). The total volume of injectate used in each group was 20 mL.All of the patients received spinal anesthesia. Postoperatively, oral paracetamol 1000 mg was givenevery 8 hours, and oral tramadol 50 mg was administered, as needed, for rescue analgesia. Thevisual analog scale (VAS) pain scores, time to first analgesic request, and total dose of postoperativeanalgesics were recorded for 3 days postoperatively.Results: The VAS scores were lower in groups I and II compared with group III. The time to thefirst analgesic was significantly shorter in group III compared with groups I and II (P = 0.001).The total dose of rescue paracetamol was higher in group III compared with groups I and II (P =0.001). No need for tramadol rescue analgesia was recorded in any of the groups. No significantdifferences between groups I and II were noticed.Limitations: The limitations of this study include the lack of previous research to compare theeffect of both intraarticular dexamethasone and dexmedetomidine added to bupivacaine forpostoperative analgesia in arthroscopic knee surgery. Additionally, there was a short observationperiod for the detection of chondrotoxicity, if occurred.Conclusion: The addition of dexamethasone or dexmedetomidine to a solution of bupivacaine0.25% provided better analgesia than using bupivacaine alone.Clinical trial registration: NCT02818985.Key words: Intraarticular, knee arthroscopy, bupivacaine, dexmedetomidine, dexamethasone,postoperative pain