Comparison of Postoperative Pain After Epidural Anesthesia Using 0.5%, 0.75% Ropivacaine and 0.5% Bupivacaine in Patients Undergoing Lower Limb Surgery: A Double-Blind Study

BACKGROUND: Ropivacaine (S (-)-1-propyl-2”, 6”; pipecoloxylidide hydrochloride) a newer long-acting amide local anesthetic has various clinical and pharmacokinetic advantages over bupivacaine. AIMS: The aim of this study is to compare the onset as well as the duration of sensory block, hemodynamic variables, and postoperative analgesia with 0.5%, 0.75% ropivacaine and 0.5% bupivacaine after epidural anesthesia for lower limb orthopedic surgery. PATIENTS AND METHODS: Sixty American Society of Anesthesiologists I and II patients scheduled for lower limb orthopedic surgery were enrolled into this randomized, double-blind study. Epidural block was obtained with 15 ml of 0.5% ropivacaine (Group I), 15 ml of 0.75% ropivacaine (Group II), and 15 ml of 0.5% bupivacaine (Group III). The onset time, duration, and maximum level of sensory blockade achieved, as well as hemodynamic parameters and any side effects, were noted and treated accordingly. Postoperative monitoring for pain by visual analog scale (VAS) was done every 2 hourly for 24 h and transient neurological symptoms for 72 h. STATISTICAL ANALYSIS: Chi-square test for nonparametric data and ANOVA for parametric data. RESULTS: Demographic characteristics were similar among groups. The onset of sensory block varied from 22.35 ± 2.74 min (mean ± standard deviation [SD]) in Group I, 16.95 ± 2.96 min (mean ± SD) in Group II, and 19.70 ± 2.25 min (mean ± SD) in Group III. The mean duration of analgesia in Group III (157 ± 14.90 min)was comparable to Group II (149 ± 16.51 min) but it was significantly more than Group I (141.5 ± 17.55 min). Postoperatively, VAS scores were higher in Group I patients who required more number of postoperative epidural top-ups with tramadol. Adverse effects were noted and treated accordingly. There was no incidence of transient neurological symptoms postoperatively. CONCLUSION: Both ropivacaine and bupivacaine provided effective epidural anesthesia for lower limb surgery. Postoperative pain was less with 0.5% bupivacaine and 0.75% ropivacaine as compared to 0.5% ropivacaine.