Intravenous injection of rocuronium is associated with withdrawal responses which are attributable to the pain from the injection of rocuronium. Several methods have been proposed to abolish and attenuate rocuronium-induced pain. We hypothesized priming dose of rocuronium could reduce withdrawal responses associated with administering a second large dose of rocuronium for tracheal intubation. We compared the efficacy of the priming dose technique of rocuronium with intravenous lidocaine as a pre-treatment for the prevention of withdrawal responses associated with rocuronium injection.

We recruited 150 patients aged between 18 and 60 years, ASA physical status 1 or 2, who were going to undergo elective surgery requiring general anesthesia. Patients were allocated into three groups. Group C received normal saline, Group L received lidocaine 1 mg/kg, and Group P received rocuronium 0.06 mg/kg 2 minutes before administering a second large dose of rocuronium for tracheal intubation. After the loss of consciousness, rocuronium 0.6 mg/kg was administered intravenously over 10 seconds for tracheal intubation. The withdrawal responses to the injection of rocuronium were evaluated.

The incidence of withdrawal responses associated with rocuronium injection for tracheal intubation was 56, 50, 24% in group C, group L, and group P, respectively. The incidence of withdrawal responses was lower in group P than group C and group L, but there was no difference between group L and group C.

Priming dose technique is a useful clinical method to alleviate withdrawal responses associated with rocuronium injection.