Summary

Background and objective: To evaluate orotracheal intubation conditions after 1 min.

Patients and methods: A prospective randomized study with 376 adult American Society of Anesthesiologists (ASA) Grade I–III patients. Each patient received propofol, fentanyl and either suxamethonium (1 mg kg−1) or rocuronium. The intubating dose of rocuronium (2 × ED95) was preceded 4 min earlier by saline, or a 0.1 × ED95 priming dose of rocuronium, atracurium, cis-atracurium, vecuronium or mivacurium. Intubating conditions were graded as excellent, good or poor with respect to laryngoscopy, vocal cord position and movement and reaction to intubation and/or cuff inflation.

Results: There were significant differences (P < 0.05) in laryngoscopy between suxamethonium and rocuronium primed with saline, atracurium or cis-atracurium. With respect to vocal cord position and movement during intubation, rocuronium without priming differed significantly from all other groups and for reaction to insertion of tracheal tube and/or cuff inflation. Rocuronium without priming differed significantly from all other groups except for rocuronium primed with itself. The mivacurium group showed more signs of pre-curarization than other groups (P < 0.05). There were significant differences between rocuronium alone and the other groups when final intubating conditions were compared.

Conclusions: Priming rocuronium with 0.1 × ED95 of vecuronium, rocuronium, atracurium or cis-atracurium is a safe technique and did not increase risk of pre-curarization in healthy patients.