The most commonly used induction agent for rapid sequence intubation in the acutely injured patient is etomidate, largely due to its rapid onset of action and hemodynamically "neutral" effects. The dose-dependent effect of etomidate in suppressing adrenal synthesis of cortisol leading to adrenal insufficiency has left the door open for ketamine to be also considered as the rapid induction agent of choice in these critically injured patients. Concerns for increased intracranial pressure, myocardial depression, and emergence reactions have also limited the use of ketamine in the trauma setting. A study published in the January 2017 issue of Annals of Emergency Medicine aims to clarify the effects of etomidate and ketamine on patient-oriented outcomes in the setting of trauma:

Upchurch et al. "Comparison of Etomidate and Ketamine for Induction During Rapid Sequence Intubation of Adult Trauma Patients." Annals of Emergency Medicine. January 2017.

Study Design: Retrospective analysis spanning 4 years (Jan 2011-Dec 2014) of 968 adult trauma patients using emotidate (0.3 mg/kg) or ketamine (1-2 mg/kg) as induction agent for rapid sequence intubation at an academic, Level I trauma center. All patients received succinylcholine as paralytic.
Primary Outcome: Hospital mortality defined as death in ED or during index hospitalization.
Secondary Outcomes:  ICU-free days, ventilator-free days, vasopressor-free days, units of PRBC transfused in first 48 hours, hospital acquired sepsis, time-to-discharge, hazard of hospital death
Results:

• Hospital Mortality: Etomidate: 91 patients (17.3%), Ketamine: 90 patients (20.4%) OR 1.41 (95% CI 0.92-2.16), no significant difference based on study design.
• No difference in ICU-free days, ventilator-free days, or vasopressor-free days.

Limitations:

• Sample size and study length potentially precluded identifying small but significant differences in mortality.
• Adrenal function not directly measured
• Single center

Conclusion: Based on this study, no mortality benefit of using ketamine over etomidate as induction agent during rapid sequence intubation in adult trauma.