TRACHEAL INTUBATION WITH ROCURONIUM USING THE TIMING PRINCIPLE

We compared the endotracheal intubating conditions after rocuronium, u sing the ''timing principle,'' with those after succinylcholine. The t iming principle entails administration of a single bolus dose of nonde polarizing muscle relaxant, followed by an induction drug at the onset of clinical weakness. Forty-five patients were randomly assigned to t hree groups. Patients allocated to Groups 1 and 2 received rocuronium 0.6 mg/kg. At the onset of clinical weakness (onset of ptosis), anesth esia was induced with thiopental 4-6 mg/kg; intubation was accomplishe d after 45 s in Group 1 and after 60 s in Group 2. Patients in Group 3 received vecuronium (0.01 mg/kg) 3 min before the administration of t hiopental and succinylcholine 1.5 mg/kg, and their tracheas were intub ated 60 s later by a blind anesthesiologist. Intubating conditions wer e assessed according to a grading scale and were either good (5 patien ts in Groups 1 and 2, 4 patients in Group 3) or excellent (10 patients in Groups 1 + 2, 11 patients in Group 3) in all patients. Patients we re interviewed postoperatively, and all were satisfied with the induct ion of anesthesia. We conclude that rocuronium 0.6 mg/kg provides good to excellent intubating conditions 45 and 60 s after the induction of anesthesia using the timing principle. Implications: We compared the ease with which a breathing tube could be placed in patients using thr ee techniques. The standard technique (succinylcholine) was compared w ith two others in which a muscle-relaxing drug (rocuronium) was admini stered just before the anesthetic drug (so-called timing principle). N o difference among the techniques was observed.