Dose of rocuronium for rapid tracheal intubation following remifentanil 2 μg kg-1 and propofol 2 mg kg-1.

CONTEXT

Full relaxation is not mandatory for successful tracheal intubation.

OBJECTIVE

We tried to find the dose of rocuronium that gave acceptable intubation conditions in a rapid sequence intubation with remifentanil and propofol.

DESIGN

A dose-finding study of rocuronium using a modified Dixon's up-and-down method.

SETTING

A single tertiary care teaching hospital.

PARTICIPANTS

Patients undergoing elective surgery under general anaesthesia.

INTERVENTIONS

After premedication with midazolam and glycopyrrolate, anaesthesia was induced using remifentanil 2 μg kg and propofol 2 mg kg, and a predetermined dose of rocuronium was administered. The dose of rocuronium was determined by a modified Dixon's up-and-down method starting from 0.8 mg kg with an interval of 0.1 or 0.05 mg kg. Intubation was performed 60 s after the start of the rocuronium injection. Intubation conditions were graded as excellent, good or poor. Excellent or good were regarded as clinically acceptable.

MAIN OUTCOME MEASURE

A dose of rocuronium needed for acceptable intubation condition in 50% of patients (ED50) during rapid tracheal intubation after induction of anaesthesia with remifentanil and propofol.

RESULTS

Twenty-eight patients were enrolled to obtain six crossovers. The ED50 of rocuronium was 0.20 mg kg (95% confidence interval, CI 0.17 to 0.23 mg kg) by a modified Dixon's up-and-down method.

CONCLUSION

After induction of anaesthesia with remifentanil 2 μg kg and propofol 2 mg kg, the ED50 of rocuronium for acceptable intubation condition was 0.20 mg kg (95% CI, 0.17 to 0.23 mg kg) for rapid sequence intubation. Thus, we recommend that the intubation dose should be 0.8 mg kg.

TRIAL REGISTRATION

Clinical trial registration KCT0000094.