Hemodynamic consequences of ketamine vs etomidate for endotracheal intubation in the air medical setting

Abstract

Objective: Recent drug shortages have required the occasional replacement of etomidate for endotracheal intubation (ETI) by helicopter emergency medical services (HEMS), with ketamine. The purpose of this study was to assess whether there was an association between ketamine vs etomidate use as the main ETI drug, with hemodynamic or clinical (airway) end points.

Methods: This retrospective study used data entered into medical records at the time of HEMS transport. Subjects, 50 ketamine and 50 etomidate, were accrued from 3 US HEMS programs. The study period was from August 2011 through May 2012. Data collection included demographics, diagnostic category, ETI drugs use, ETI success, and complications. Hemodynamic parameters were assessed for up to 2 sets of vital signs before airway management and up to 5 sets of post-ETI vital signs. Significance was defined at the P < .05 level.

Results: Patients on ketamine and etomidate were similar (P > .05) with respect to age, sex, scene/interfacility mission type, trauma vs nontrauma, neuromuscular blocking agent use, and rates of coadministration of fentanyl or midazolam. All patients had successful airway placement. Peri-ETI hypoxemia was seen in 10% of etomidate and 16% of ketamine cases (P = .55). The pre-ETI and post-ETI were similar between the ketamine and etomidate groups with respect to systolic blood pressure and heart rate at every vital signs assessment after ETI.

Conclusion: Initial assessment of ETI success and complication rates, as well as peri-ETI hemodynamic changes, suggests no concerning complications associated with large-scale replacement of etomidate with ketamine as the major airway management drug for HEMS.