A prospective randomized double‐blinded controlled study of ropivacaine 0.75% versus bupivacaine 0.5%‐mepivacaine 2% for peribulbar anesthesia

Background and Objectives: Ropivacaine 1% has recently been used in clinical trials for peribulbar anesthesia. This study aims to compare the safety and the efficacy of ropivacaine 0.75% with that of a 1:1 mixture of bupivacaine 0.5% and mepivacaine 2% for peribulbar anesthesia. Methods: Two thousand patients undergoing peribulbar anesthesia for elective cataract phacoemulsification were prospectively studied over a 1‐year period and randomly assigned to 1 of 2 groups according to the local anesthetic used. One thousand patients were administered peribulbar anesthesia with 9 mL of ropivacaine 0.75% plus 1 mL of hyaluronidase (group R), and 1,000 patients received peribulbar anesthesia with 4 mL of bupivacaine 0.5% plus 4 mL of mepivacaine 2% plus 1 mL of hyaluronidase plus 1 mL of sodium bicarbonate (group BM). Peribulbar anesthesia was always accomplished by the same physician by 2 injections of 5 mL each, with a 25‐gauge 25‐mm needle. Evaluation was performed by another physician blinded to the technique used and included assessment of pain on local anesthetic injection, ocular and eyelid akinesia, need for top‐up injections, onset time and duration of anesthesia, intraoperative analgesia, duration of surgery, hemodynamic parameters, and incidence of perioperative complications. Results: A greater incidence of pain on injection was found in group BM (P < .001). No difference between the groups was found regarding the onset time and the duration of anesthesia. Perioperative analgesia was satisfactory in both groups with no significant difference. Patients in group R showed a reduced need for top‐up injection and a better ocular akinesia at 8 and 10 minutes (P < .01). The akinesia of the eyelid was comparable in the 2 groups and complete in all cases at 8 minutes. Cardiac arrhythmias were more frequent in group BM (P < .01). Local complications did not differ between the groups. An increase in mean artierial blood pressure and heart rate was observed in both groups 1 minute after injection of local anesthetic. Conclusions: Peribulbar anesthesia with ropivacaine provided better ocular akinesia 8 to 10 minutes after block insertion than a bupivacaine‐mepivacaine mixture, which reduced the need for top‐up injections. Ropivacaine also caused less pain on injection. Reg Anesth Pain Med 2000;25:195‐200.