Rapid tracheal intubation with rocuronium: a probability approach to determining dose.
BACKGROUND
Rapid tracheal intubation with rocuronium has not been studied using a probability-based approach. The authors aimed to predict doses of rocuronium giving 90% and 95% probability of in intubation within 60 s and to estimate their durations of action.


METHODS
After premedication with midazolam, 2 mg, anesthesia was induced in 80 subjects with fentanyl, 2 microg/kg, followed 3 min later by propofol, 2 mg/kg. Patients received randomly rocuronium, 0.0, 0.4, 0.8, or 1.2 mg/kg (n = 20/ dose). Laryngoscopy began 40 s later, aiming for intubation at 60 s, and conditions were graded perfect, acceptable, or unacceptable, with the first two conditions being successful intubation. Anesthesia was maintained with isoflurane 0.5-1.0% (end-tidal) and fentanyL Duration of action was time until reappearance of the first tactile train-of-four response. The dose versus fraction of patients with successful intubation was analyzed by logistic regression. Doses giving 90% and 95% (D90 and D95) probability of successful intubation were calculated.


RESULTS
intubation was successful in 7, 11, 18, and 19 patients in the 0.0, 0.4, 0.8, and 1.2 mg/kg groups, respectively. The D90 and D95 doses (95% confidence limits in parentheses) were 0.83 (0.59-1.03) and 1.04 (0.76-1.36) mg/kg, respectively. Estimated time until first tactile train-of-four response after D90 and D95 doses was 32 and 46 min, respectively.


CONCLUSIONS
After induction with fentanyl and propofol, rocuronium, 1.04 mg/kg gives 95% probability of successful intubation at 60 s.
Kirkegaard-Nielsen
H
H
Department of Anesthesia and Perioperative Care, University of California, San Francisco 94143-0648, USA.
Caldwell
J E
JE
Berry
P D
PD
D000328:Adult; D000732:Androstanols / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal; D008297:Male; D008875:Middle Aged; D003473:Neuromuscular Nondepolarizing Agents / Q000494:pharmacology*; D011336:Probability; D000077123:Rocuronium; D013997:Time Factors
D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D000077123:Rocuronium