[Evaluation of the timing principle with vecuronium]

We evaluated the usefulness of the timing principle with vecuronium in 60 patients who underwent elective surgery, and divided into two groups according to the dose of vecuronium (0.15 and 0.2 mg.kg-1). First, we studied the interval between vecuronium and thiopental administration in 40 patients. The time after vecuronium administration to onset of clinical muscle weakness was 57.6 +/- 7.8 sec in 0.15 mg.kg-1, and 42.2 +/- 2.2 sec in 0.2 mg.kg-1 group. Then, we made and examined the protocol of the timing principle for the rapid tracheal intubation. Induction of anesthesia with 4-5 mg.kg-1 thiopental was done 40 sec after 0.15 mg.kg-1 in 10 patients, and 30 sec after 0.2 mg.kg-1 vecuronium administration in 10 patients. Intubating conditions were almost excellent 70 sec after thiopental administration. In our study, there were no patients who experienced discomfort during induction. We conclude that the timing principle with vecuronium is useful for rapid-sequence tracheal intubation.