ABSTRACT

Background: Intra-articular drugs and local anaesthetics are the most popular methods for pain relief after arthroscopic knee procedure. Many drugs, including opioids, non-steroidal antiinflammatory drugs, ketamine, clonidine, and neostigmine, have been used intra-articularly. Objectives: The aim of our study was to compare the analgesic effect of intraarticular injection of ketamine bupivacaine and neostigmine bupivacaine in patients undergoing arthroscopic knee surgery under intra-thecal anaethesia. Design: a randomized controlled trial included 100 Patients were randomly divided into two groups 50 patients each, setting: the study was conducted in Assuit university tertiary hospital, Egypt. Intervevtions: Neostigmine group received intra-articular 0.5mg/dose neostigmine + 20 ml 0.25% bubivacaine and ketamine group received intra-articular 0.5 mg/kg ketamine + 20 ml 0.25% bubivacaine. VAS score was used for post-operative evaluation of pain every 4 hours over a 24 hour period. The total analgesic dose and any side effects were also recorded. Results: There were no significant differences in VAS score between the two studied groups but Time to rescue analgesia was significantly longer in the ketamine group (447.70± 48.109 minutes) than in the neostigmine group (257.60± 47.243 minutes) with P value ≤ 0.000. There was a significant difference in the analgesic dose of ketorolac between ketamine group and neostigmine group. Conclusion: Injection of intra-articular ketamine bupivacaine provided better postoperative analgesia, less side effects and low supplementary analgesic dose than intra-articular neostigmine bupivacaine. Trial registration: This study is registered by the local research ethics committee and its Approval Number: IRB00008788 and registered at www.clinicaltrials.gov under number NO: NCT02720705. Key words: analgesic dose, intra-articular, ketamine, neostigmine