Intubating Conditions and Hemodynamic Effects of Etomidate for Rapid Sequence Intubation in the Emergency Department: An Observational Cohort Study

Objectives: To describe and analyze the intubating conditions and hemodynamic effects of etomidate in patients undergoing rapid sequence intubation (RSI) in the emergency department. Methods: The authors conducted a prospective observational study of all patients who received etomidate for induction of RSI over a 42-month period in a large tertiary care teaching hospital. Intubating conditions were determined by the emergency physician for both sedation and paralysis and for technical difficulty using a five-point Likert scale. Hemodynamic effects were evaluated before, after, and every five minutes for 15 minutes following administration of etomidate. Results: Etomidate was used for induction of RSI in 522 patients, all of whom were included in the final efficacy analysis, while 491 were included in the analysis of hemodynamics. Lidocaine and fentanyl were used as pretreatment in 65.1% and 26.1% of patients, respectively, while succinylcholine was the paralytic in 94.3% of intubations. Sedation and paralysis were rated as excellent or good in 88.1% and 8.8% of patients, respectively, while technical difficulty was very easy or easy in 60.7% and 19.0% of patients, respectively. Mean (± SD) baseline systolic blood pressure (sBP), diastolic blood pressure (dBP), and heart rate were found to be 132.7 (± 35.4) mm Hg, 69.5 (± 21.2) mm Hg, and 96.1 (± 26.2) bpm, respectively. Overall, there was a clinically insignificant elevation in sBP (p < 0.0001), dBP (p = 0.0002), and heart rate (p < 0.0001) immediately postintubation. Elevations in sBP persisted at five minutes (p = 0.0230) and ten minutes (p = 0.0254) postintubation. Diastolic blood pressure and heart rate returned to baseline at five minutes after intubation and remained stable throughout the 15-minute postintubation assessment period. In the subgroup of 80 patients with a preintubation sBP < 100 mm Hg, there was a 12.1–mm Hg elevation in sBP (p < 0.0001) and a 7.3–mm Hg elevation in dBP (p = 0.0001) immediately postintubation. This elevation persisted throughout the 15-minute postintubation assessment period. Conclusions: Etomidate appears to provide appropriate intubating conditions in a heterogeneous group of patients undergoing RSI in the emergency department. Hemodynamic stability appears to be present following administration of this agent, even in patients with low pre-RSI blood pressure. This attribute must be weighed against potential adverse effects of this agent, including adrenal suppression.