Evaluation of Post-operative Analgesic Efficacy of Adductor Canal Block Compared to Conventional Intravenous Analgesics in Knee Arthroscopy Surgery

Background: Effective post-operative pain management is essential for early recovery and patient satisfaction following knee arthroscopy. This study aimed to evaluate the post-operative analgesic efficacy and safety of ultrasound-guided adductor canal block (ACB) compared to conventional intravenous morphine analgesia. Materials and Methods: This randomized, controlled, interventional study was conducted in the post-anesthesia care unit (PACU) of the Department of Anesthesiology in an Indian Hospital. Eighty adult patients (American Society of Anesthesiologists [ASA] I–II) undergoing unilateral knee arthroscopy under general anesthesia were randomly divided into two groups: Group M received intravenous morphine (0.1 mg/kg) before incision, and Group B received an ultrasound-guided ACB with 15 mL of 0.25% bupivacaine before extubation. Post-operative analgesic efficacy was assessed by the requirement of rescue analgesia and the time to achieve a Visual Analog Score (VAS) <3. Adverse effects and antiemetic requirements were also recorded. Statistical analysis was performed using the Statistical Package for Social Sciences version 17.0, and a P < 0.05 was considered significant. Results: Both groups were comparable in terms of age, sex, ASA physical status, and pre-operative vitals (P > 0.05). Rescue analgesia in the PACU was required in 47.5% of patients in Group M and 10.0% in Group B (P < 0.001). The mean time to achieve VAS <3 was significantly shorter in Group B (11.00 ± 3.79 min) compared to Group M (16.00 ± 9.00 min) (P = 0.002). The requirement of antiemetic medication was lower in Group B (20.0%) than in Group M (42.5%) (P = 0.030). No adverse events were reported in either group. Conclusion: Ultrasound-guided ACB provides superior post-operative analgesia, faster pain relief, and fewer side effects compared to intravenous morphine in patients undergoing knee arthroscopy.