Effects of atracurium added to local anesthetics on akinesia in peribulbar block

Background and Objectives: Peribulbar anesthesia (PBA) is widely used in cataract surgery, but the onset time of akinesia is not as rapid as with retrobulbar block. The aim of this study was to evaluate whether addition of low-dose atracurium to the local anesthetic mixture has any effects on akinesia in PBA. Methods: Sixty adults undergoing cataract surgery were randomly allocated to receive either 8 mL of a lidocaine-bupivacaine mixture, plus 0.5 mL 0.9% NaCl (group I) or 8 mL of the same local anesthetic mixture plus 0.5 mL (5 mg) atracurium (group II). The level of akinesia was graded by a observer unaware of group assignment. The onset time and duration of akinesia were also recorded by an observer, again unaware of group assignment. Results: The onset time of complete akinesia in group II was significantly shorter than that in group I (P <.05). In group I, 86% of patients had an akinesia score of 0 (complete akinesia) in the first 10 minutes. The rate of complete akinesia was 93% in group II in the same period. This difference was not significant. The success rate of complete akinesia was 93% in group I and 100% in group II at the end of the measurement interval. None of the group II patients required supplementary block, while 2 patients in group I received additional injections for inadequate akinesia. Conclusion: Atracurium added at a dose of 5 mg to a lidocaine-bupivacaine mixture for peribulbar block decreases the onset time of akinesia and provides better surgical conditions without obvious side-effects.