Reversal of rocuronium with edrophonium during propofol versus sevofluraneanesthesia

Background: The use of volatile anesthetics for maintenance of anesthesia c an enhance the action of non-depolarizing muscle relaxants and interfere wi th the reversal of neuromuscular blockade. In this study, we studied the an tagonism of rocuronium with edrophonium-atropine during propofol- versus se voflurane-based anesthesia. Methods: Following induction of anesthesia with propofol (2-2.5 mg kg(-1), iv) and fentanyl (1-2 mug kg(-1) iv), rocuronium 0.6 mg kg(-1) iv was admin istered to facilitate tracheal intubation. Patients were then randomized to receive either a propofol infusion (100 mug kg(-1) min(-1)) or sevoflurane (1.0%, end-tidal) in combination with nitrous oxide 66% for maintenance of anesthesia. Neuromuscular blockade was monitored using electromyography at the wrist, and reversed with edrophonium 1.0 mg kg(-1) and atropine 0.015 mg kg(-1) when the first twitch hight (T-1) of the train-of-four (TOF) stim ulation recovered to 25% of the baseline value. Anesthetic maintenance with propofol or sevoflurane was continued following reversal until a TOF ratio of 0.7 was attained. Results: The clinical duration of action (i.e., time to 25% T-1 recovery) w as similar during both propofol- (39.3+/-14.6 min) and sevoflurane-based (4 8.1+/-19.7 min) anesthesia. However, the reversal time from 25% T-1 to TOF ratio of 0.7 was significantly longer with sevoflurane [Median 2.8 (range 0 .5-18.8) min] compared with propofol [1.5 (0.75-3) min] (P<0.05). Conclusions: We conclude that the clinical duration of action after a singl e dose of rocuronium, 0.6 mg kg(-1) iv, was similar during both propofol- a nd sevoflurane-based anesthesia. However, the reversal of rocuronium-induce d residual blockade was slower and more variable in the presence of sevoflu rane.