Ketamine vs Etomidate for Prehospital Drug Assisted Intubation

Emergency Medical Services (EMS) clinicians commonly use ketamine and etomidate to facilitate drug-assisted intubation, however the association of medication choice on mortality is unclear. The objective of this study was to compare survival among patients intubated by EMS with ketamine or etomidate.

We conducted an observational cohort study using a national EMS registry (ESO Solutions, Austin Tx). Adult patients who received a 911 response and had a drug-assisted intubation attempted by EMS using either ketamine or etomidate during 2022 were included. Patients who suffered cardiac arrest prior to the first intubation attempt were excluded. The primary outcome was survival to hospital discharge. The secondary outcome was survival to hospital admission. Survival to hospital discharge and admission rates were compared between the ketamine and etomidate groups using chi-square tests. The odds of survival to hospital discharge by induction agent were estimated with a multivariable logistic regression model, adjusting for age, sex, race, paralytic agent use, intubation method, pre-intubation vital signs (systolic blood pressure, heart rate, and oxygen saturation), and call type (medical vs trauma), with etomidate as the reference group.

We accrued 5348 patients, with 41.9% (2241/5348) female, 31.4% (1678/5348) non-White, and a median age of 61 years (IQR 42-73). Ketamine was administered to 54.4% (2910/5348). Survival to hospital discharge rates were similar in the ketamine and etomidate groups (93.1% [2708/2910] and 92.3% [2249/2438]; p=0.26). Survival to hospital admission occurred in 98.4% (2862/2910) of patients who received ketamine and 98.3% (2397/2438) of those who received etomidate(p=0.93). After adjusting, the odds of survival to hospital discharge (aOR 1.21, 95%CI 0.84-1.54) and survival to hospital admission (aOR 1.28, 95%CI 0.78-2.12) were similar for ketamine compared to etomidate.

Among patients in whom drug-assisted intubation was attempted by EMS, there was no difference in survival to hospital discharge or survival to hospital admission among those who received ketamine versus etomidate.