Postintubation hypotension following rapid sequence intubation with full- vs reduced-dose induction agent

Rapid sequence intubation (RSI) is a common emergency department (ED) procedure with an associated complication of postintubation hypotension (PIH). It has not been clearly established whether the selection and dose of induction agent affect risk of PIH. The objective of this study was to determine the incidence of PIH in patients receiving full-dose compared to reduced-dose induction agent for RSI in the ED.

This was a health system-wide, retrospective cohort study comparing incidence of PIH based on the induction medication and dose given for RSI in the ED. Patients were included if they underwent RSI from July 1, 2018, through December 31, 2020, were 18 years of age or older, and received etomidate or ketamine. A reduced dose was defined as a ketamine dose of 1.25 mg/kg or less and an etomidate dose of 0.2 mg/kg or less.

A total of 909 patients were included in the final analysis, with most receiving etomidate (n = 764; 84%) and a smaller number receiving ketamine (n = 145; 16%). Patients who received ketamine had a higher mean pre-intubation shock index (full dose, 1.08; reduced dose, 1.04) than those who received etomidate (full dose, 0.89; reduced dose, 0.92) (P ≤ 0.001). Reduced doses of induction agent were observed for 107 patients receiving etomidate (14.0%) and 60 patients receiving ketamine (41.4%). Patients who received full-dose ketamine for induction had the highest rate of PIH (n = 31; 36.5%), and the difference was statistically significant compared to patients receiving reduced-dose ketamine (16.7%; P = 0.021) and full-dose etomidate (22.8%; P = 0.010).

We observed that full-dose ketamine was associated with the highest rate of PIH; however, this group had the poorest baseline hemodynamics, confounding interpretation. Our results do not support broad use of a reduced-dose induction agent.