Intubating conditions using cisatracurium after induction of anaesthesia with thiopentone

We studied tracheal intubation conditions produced by the muscle relaxant, cisatracurium, following induction of anaesthesia with fentanyl (2 micrograms.kg-1) and thiopentone (6 mg.kg-1). Sixty patients were randomly assigned to receive cisatracurium in a single bolus dose of either 0.15 or 0.20 mg.kg-1. Tracheal intubation was commenced 120 s after injection of the relaxant. The mean (SD) time taken to achieve intubation was significantly shorter in the 0.20 mg.kg-1 group (137 (16) s) than the 0.15 mg.kg-1 group (149 (12) s; p < 0.05). The intubating conditions were better after the larger dose. Our results suggest that when anaesthesia is induced using thiopentone, a dose of 0.20 mg.kg-1 of cisatracurium is recommended to ensure satisfactory intubating conditions.