Does the sedative agent facilitate emergency rapid sequence intubation?

Objectives: To ascertain whether the sedative agent administered during neuromuscular-blocking agent-facilitated intubation (rapid sequence intubation [RSI]) influences the number of attempts and overall success at RSI. Methods: Records were drawn from an ongoing, prospective multicenter registry of emergency department intubations. Conditional logistic regression stratified by institution was used to identify factors associated with multiple intubation attempts and unsuccessful RSI. Results: 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 0.51 [95% CI = 0.23 to 1.13]) prior to neuromuscular blockade was associated with a lower likelihood of successful intubation on the first attempt, as compared with thiopental, methohexital, or propofol. The adjusted odds ratios for the likelihood of overall success had similar point estimates, but did not reach statistical significance due to lack of power (p = 0.2, with 36 unsuccessful intubations). Among patients receiving etomidate, intubation was more likely to be successful on the first attempt with increasing doses of either etomidate or succinylcholine. Conclusions: Thiopental, methohexital, and propofol appear to facilitate RSI in emergency department patients, independent of patient characteristics or intubator training. A deeper plane of anesthesia may improve intubating conditions in emergency patients undergoing RSI by complementing incomplete muscle paralysis.