Hemodynamic Effects of Ketamine Versus Etomidate for Prehospital Rapid Sequence Intubation

Rapid sequence intubation (RSI) is often required in managing critically ill patients in the prehospital setting. Although etomidate is a commonly used induction agent for RSI, ketamine has gained new interest in prehospital management with reported neutral hemodynamic effects. Limited data exist to support ketamine as an alternative to etomidate, particularly in the prehospital setting. The purpose of this study was to evaluate hemodynamic changes after the administration of ketamine versus etomidate in prehospital RSI.

This retrospective study evaluated adult patients undergoing prehospital RSI over 13 months within a regional emergency transport medicine service. Hypotension was defined as a 20% decrease in systolic blood pressure (SBP) within 15 minutes of receiving ketamine or etomidate. Hemodynamic data were collected 15 minutes before and 15 minutes after administration or until additional sedative medications were given. Data were analyzed using SPSS software (Version 21; IBM Corp, Armonk, NY), with P < .05 considered significant.

One hundred thirteen patients met the inclusion criteria (ketamine, n = 33; etomidate, n = 80), with the primary reasons for intubation being respiratory failure and trauma. There was no difference between the incidence of patients who experienced a 20% decrease in SBP (16% etomidate vs. 18% ketamine, P = .79). There were no significant differences in SBP pre- to postadministration between ketamine and etomidate.

No hemodynamic differences occurred between patients who received ketamine versus etomidate for prehospital RSI. Neither drug was associated with an increased need for additional sedatives, and neither drug was associated with an increased first-pass intubation success rate. Larger, prospective, powered studies are required to identify patients who may benefit from either ketamine or etomidate.