Of 3,407 intubations over 33 months in 22 institutions, 2,380 involved RSI. After correcting for the specialty and experience of the intubator and for the presence of airway aberrancy, the sedative agent was significantly associated with the number of attempts at intubation (p = 0.002). Specifically, the use of etomidate (adjusted odds ratio [OR] 0.35 [95% CI = 0.17 to 0.72]), ketamine (OR 0.27 [95% CI = 0.11 to 0.65]), a benzodiazepine (OR 0.47 [95% CI = 0.23 to 0.95]), or no sedative agent (OR 0