Comparison of the Efficacy of Intrathecal Isobaric Ropivacaine and Bupivacaine in Day Care Knee Arthroscopy: A Randomized Controlled Trial

BACKGROUND: The primary goal of ambulatory anesthesia is a rapid recovery with minimal side effects. Ropivacaine, due to its property of sensory-motor dissociation, maybe a useful agent when equivalent spinal anesthesia and quicker recovery of motor function is desirable. AIM: The aim of this study is to compare the efficacy of intrathecal isobaric ropivacaine with bupivacaine and to assess their postoperative recovery profile in patients undergoing arthroscopic knee surgery. SETTING AND DESIGN: This randomized controlled study was conducted at a tertiary care hospital. MATERIALS AND METHODS: A total of 90 adult American Society of Anaesthesiologist physical status Classes 1 and 2 patients were randomized into two groups to receive 2 ml plain solution of either 0.5% bupivacaine (Group B) or 0.75% ropivacaine (Group R). In the intraoperative period, onset, efficacy, duration, and regression of sensory and motor block were noted in both the groups at regular intervals. Postoperatively, the groups were compared for pain score, recovery profile, analgesic requirement, and complications. STATISTICAL ANALYSIS: Data analysis was performed using Chi-square test and Student's t-test. RESULTS: The mean onset time of sensory block at L1 was significantly less (P = 0.025) and duration of sensory and motor block was significantly more (P = 0.001) with bupivacaine as compared to ropivacaine. The analgesic requirement on the 1(st) postoperative day (P = 0.011) and incidence of delayed voiding of urine (P = 0.022) were significantly more with ropivacaine. The postoperative recovery profile and discharge times were similar between the groups. CONCLUSION: Isobaric ropivacaine was associated with a longer onset and shorter duration of sensory and motor block, increased postoperative analgesic requirement, higher complication rate, and similar discharge times as compared with bupivacaine. Therefore, isobaric bupivacaine may be preferred over isobaric ropivacaine for day care knee arthroscopy, especially in cases with an anticipated longer duration of surgery.