A prospective comparison of the efficacy of 0.5% bupivacaine vs 0.75% ropivacaine in peribulbar anesthesia for vitreoretinal surgery

PURPOSE: To date, there is no information on the comparison of the effect of 0.5% bupivacaine with 0.75% ropivacaine solution for vitreoretinal surgery. The aim of the study was to compare the efficacy of 0.5% bupivacaine with 0.75% ropivacaine in peribulbar anesthesia for vitreoretinal surgery. This was a prospective randomized double-blinded observational study in a hospital setting. Sixty patients planned for vitreoretinal surgery were randomized into two groups based on the peribulbar injection administered either with 0.5% bupivacaine or 0.75% ropivacaine solution, as Group B (n = 30) and Group R (n = 30), respectively. Time of onset of analgesia, akinesia, and the need for supplemental anesthesia were noted. Student's t-test or Mann-Whitney U test were used for comparing continuous variables and Chi-square or a Fischer exact test were used as appropriate for comparing two proportions. RESULTS: The patients in Group R showed an earlier onset of both, analgesia (1.97 min vs. 2.10 min, P = 0.002) and akinesia (2.77 min vs. 4.20 min, P < 0.001) compared with the patients in Group B. The efficacy of the block attained was Grade 5 (adequate anesthesia and akinesia without supplementation) in about 97% of the patients in Group R while only 90% in Group B. However, the differences between the groups for the efficacy of the block were not statistically significant (P = 0.301) neither for Grades 5 nor for Grade 4 and 3 (P = 1.00 for both). The onset of postoperative pain was similar for both groups (P = 1.00). CONCLUSION: We concluded that 0.75% ropivacaine is a better choice of local anesthetic solution for patients undergoing primary vitreoretinal surgery compared with 0.5% bupivacaine.