Priming with rocuronium to accelerate the onset time of cisatracurium during intubation.

BACKGROUND The priming technique, in which a small dose of nondepolarizing muscle relaxant is administered 3-6 minutes before giving the intubation dose, can speed up the onset of muscle relaxation in patients with paralysis during intubation. We investigated the priming technique and compared 2 different priming agents (rocuronium and cisatracurium) at a priming time of 3 minutes and its effect on decreasing the onset time of cisatracurium. METHODS A total of 60 patients with ASA physical status I-II scheduled for elective surgery were enrolled. After induction with propofol and fentanyl, the patients were randomized into 1 of 3 groups. Group 1 received rocuronium 0.06 mg/kg as a priming dose. Group 2 received cisatracurium 0.01 mg/kg as a priming dose. Group 3 received normal saline and constituted the control group. After a 3-minute priming time, intubation doses of cisatracurium were given (Groups 1 and 2, 0.14 mg/kg; Group 3, 0.15 mg/kg). First twitch height percentage (T1/T0%; % of control) and train-of-four percentage (T4/T1%) were recorded every 10 seconds from baseline until T1/T0% reached 0. RESULTS Rocuronium (Group 1) and cisatracurium (Group 2) significantly accelerated the onset of cisatracurium (Group 1, 117.0 +/- 29.0 seconds; Group 2, 151.0 +/- 37.5 seconds; Group 3, 221.5 +/- 36.6 seconds; all p < 0.001). CONCLUSION Priming with rocuronium or cisatracurium for 3 minutes significantly accelerated the onset of cisatracurium. Priming with rocuronium for 3 minutes improved the onset time of cisatracurium even more than priming with cisatracurium itself.