Propofol, Ketamine, and Etomidate as Induction Agents for Intubation and Outcomes in Critically Ill Patients: A Retrospective Cohort Study

IMPORTANCE: Propofol, ketamine, and etomidate are common anesthetic agents for induction of anesthesia in the ICU. The choice between these agents is complex and may not depend solely upon severity of illness. OBJECTIVES: To evaluate the association between the administration of propofol, ketamine, and etomidate and ICU, hospital mortality, and length of stay. DESIGN, SETTING, AND PARTICIPANTS: Retrospective single-center cohort study. ICUs in a tertiary medical center, between January 01, 2012, and December 31, 2017. Critically ill adult patients given a single IV anesthetic for intubation. MAIN OUTCOME AND MEASURES: Primary outcomes were ICU and hospital mortality. Secondary outcomes were ICU- and hospital-free days through 28 days. An inverse probability of treatment weighed approach was used. The propensity score was estimated using a generalized logit model as a function of patient characteristics, admission source, ICU type, readmission status, length of ICU stays prior to intubation, and acute physiology score. Mortality outcomes were assessed with weighted logistic regression and -free days assessed by weighted linear regression with Bonferroni correction for pairwise comparisons. RESULTS: Of 2,673 patients, 36% received propofol, 30% ketamine and 34% etomidate. Overall ICU and hospital mortality were 19% and 29%, respectively. Patients given ketamine had higher odds of ICU mortality (1.45; [95% CI, 1.07–1.94]; p = 0.015) and patients given etomidate had higher odds of ICU mortality (1.87; 1.40–2.49; p < 0.001), hospital mortality (1.43; 1.09–1.86; p = 0.009), and less ICU-free days (–2.10; –3.21 to –1.00; p < 0.001) than those given propofol. Patients given ketamine and etomidate had similar odds of hospital mortality (1.06; 0.80–1.42; p = 0.761) and similar hospital-free days (0.30; –0.81 to 1.40; p = 0.600). CONCLUSIONS AND RELEVANCE: Compared with ketamine and etomidate, propofol was associated with better outcome in critically ill patients undergoing anesthesia for intubation. Even after adjusting for severity of illness prior to intubation, residual confounders cannot be excluded.