Effects of nicardipine on the onset time and intubation conditions of rocuronium-induced neuromuscular blockade

Abstract Study objective The objective of this study was to identify the effects of nicardipine on neuromuscular blockade of rocuronium, such as the onset time and intubation conditions, using a nicardipine dose that attenuates cardiovascular responses during endotracheal intubation. Design Randomized, double-blinded, placebo-controlled clinical comparison was used as the design of this study Setting The study was conducted at the operating room of a university hospital. Patients Participants of this study comprise 78 American Society of Anesthesiologists physical status 1 and 2 patients, aged 18 to 60 years who were undergoing elective surgery under general anesthesia. Interventions The nicardipine group was given an intravenous bolus of 20 μ g/kg nicardipine before tracheal intubation: the control group was given an intravenous bolus of a comparable volume of normal saline before tracheal intubation. Measurements Using a TOF-Watch SX monitor, the time from the end of the injection of rocuronium to maximum depression of T1 (onset time) was measured. Intubation was performed 1 minute after rocuronium administration, and the status of the intubation conditions was assessed. The mean blood pressure and heart rate were each measured after endotracheal intubation. Rate pressure product values were also calculated. Main results Intubation conditions were clinically acceptable in 37 (94.9%) of 39 patients in group N compared with 29 (74.4%) of 39 in group C ( P < .05). The onset time of rocuronium was significantly faster in group N than in group C ( P < .05). The mean blood pressure was significantly lower in group N than in group C ( P < .05). The heart rate was significantly higher in group N than in group C ( P < .05). Rate pressure product values showed no significant difference between the two groups ( P > .05). Conclusions Pretreatment with 20 μ g/kg nicardipine improves intubation conditions, shortens the onset time of rocuronium, and attenuates cardiovascular responses to tracheal intubation.