Effects of local low-dose rocuronium on the quality of peribulbar anesthesia for cataract surgery

OBJECTIVES: Peribulbar anesthesia is associated with delayed and/or incomplete orbital akinesia compared with retrobulbar anesthesia. This study examined the effects of adding rocuronium 5 mg to two different concentrations of lidocaine-bupivacaine mixture on onset time of orbital and eyelid akinesia in patients undergoing cataract surgery. METHODS: In a double-blind study, 90 patients were equally randomized to receive a mixture of 0.5 ml normal saline, 4 ml lidocaine 2%, and 4 ml bupivacaine 0.5% (group I), a mixture of rocuronium 0.5 ml (5 mg), 4 ml lidocaine 2%, and 4 ml bupivacaine 0.5% (group II), or a mixture of rocuronium 0.5 ml (5 mg), 4 ml lidocaine 1%, and 4 ml bupivacaine 0.25% (group III). Orbital akinesia was assessed on a 0-8 score (0 = no movement, 8 = normal) at 2 min intervals for 10 min. Time to adequate anesthesia was also recorded. Results are presented as mean±SD. RESULTS: Ocular movement score decreased during the assessment period in all groups. However, at 2 min after block administration, the score decreased to 4±2 (95% CI 3,5) in groups II and III compared with 5±2 (95% CI 4,6) in group I (P<0.01). Time to adequate condition to begin surgery was 9.8±2.9 vs. 6.9±4.1 vs. 7.9±3.9 min for groups I, II, and III, respectively (P=0.01). CONCLUSION: The addition of rocuronium 5 mg to a mixture of lidocaine 2% and bupivacaine 0.5% shortened the onset time of peribulbar anesthesia in patients undergoing cataract surgery without causing adverse effects.