Reversal of neuromuscular blockade with sugammadex during continuous administration of anaesthetic agents: a double‐blind randomised crossover study using the bispectral index

Summary Sugammadex, a specific reversal agent for steroidal neuromuscular blocking drugs, has on occasion been reported to be associated with clinical signs of awakening. We performed a study to systematically search for an increase in bispectral index values and signs of awakening in patients maintained under general anaesthesia following sugammadex administration. Patients, scheduled to receive general anaesthesia with neuromuscular blockade, were included in this double‐blind randomised crossover study. After surgery was completed, and while the train‐of‐four ratio was zero, intravenous anaesthesia was continued with the aim of maintaining the bispectral index in the range of 40–60. Patients then received either sugammadex 4 mg.kg−1 or saline. In cases of incomplete reversal of neuromuscular blockade after 5 min, patients received the other drug. Bispectral index and train‐of‐four monitoring were recorded every minute and clinical signs of awakening noted. Fifty‐one patients completed the study. Median (IQR [range]) bispectral index values increased after sugammadex administration from 49 (43–53 [38–64]) to 63 (53–80 [45–97]) (p