Rapacuronium 2.0 or 2.5 mg kg–1 for rapid‐sequence induction: comparison with succinylcholine 1.0 mg kg–1

The purpose of this nine-centre study in 602 patients was to show that the frequency of acceptable intubating conditions after rapacuronium 2.0 or 2.5 mg kg −1 is not more than 10% lower than the frequency after succinylcholine 1.0 mg kg −1 during rapid-sequence induction of anaesthesia with fentanyl 1–2 μg kg −1 and thiopental 2–7 mg kg −1 . Laryngoscopy and intubation were carried out 60 s after administration of muscle relaxant by an anaesthetist blinded to its identity. Intubating conditions were clinically acceptable (excellent or good) in 91.8% of patients given succinylcholine and in 84.1 and 87.6% of patients given rapacuronium 2.0 and 2.5 mg kg −1 respectively. With respect to the percentage of clinically acceptable intubating conditions, the estimated difference (and the upper limit of the one-sided 97.5% confidence interval) between succinylcholine and rapacuronium 2.0 mg kg −1 was 7.8 (14.4)% and between succinylcholine and rapacuronium 2.5 mg kg −1 it was 4.0 (10.2)%. For both comparisons, the upper limit of the one-sided confidence interval exceeded the predefined 10% difference. Hence, it could not be demonstrated that the intubating conditions with either of the two doses of rapacuronium were not inferior to those with succinylcholine 1.0 mg kg −1 . The increase in heart rate was significantly greater during the first 5 min in the rapacuronium groups, but the arterial pressure increased significantly only in the succinylcholine group ( P −1 respectively ( P −1 could not be proven, succinylcholine should be considered the neuromuscular blocking agent that provides better intubating conditions for rapid-sequence induction.