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 μgkg⁻¹) and thiopentone (6 mgkg⁻¹). Sixty patients were randomly assigned to receive cisatracurium in a single bolus dose of either 0.15 or 0.20 mgkg⁻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 mgkg⁻¹ group (137 (16) s) than the 0.15 mgkg⁻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 mgkg⁻¹ of cisatracurium is recommended to ensure satisfactory intubating conditions.