Background: Emergency tracheal intubation is a common and high-risk procedure. Ketamine and etomidate are medicines commonly used to induce anesthesia for emergency tracheal intubation, but whether the induction medication used affects patient outcomes is uncertain.

Research question: Does the use of ketamine for induction of anesthesia decrease the incidence of death among adults undergoing emergency tracheal intubation compared with the use of etomidate?

Study design and methods: The Randomized Trial of Sedative Choice for Intubation (RSI) is a pragmatic, multicenter, unmasked, parallel-group randomized trial being conducted at 14 sites (6 emergency departments and 8 ICUs) in the United States. The trial compares ketamine vs etomidate for induction of anesthesia among 2,364 critically ill adults undergoing emergency tracheal intubation. The primary outcome is all-cause 28-day in-hospital mortality. The secondary outcome is the incidence of cardiovascular collapse during intubation, a composite of hypotension, receipt of vasopressors, and cardiac arrest.

Results: Enrollment began on April 6, 2022, and is expected to conclude in 2025.

Interpretation: The RSI will provide important data on the effects of ketamine vs etomidate on death and other outcomes for critically ill adults undergoing emergency tracheal intubation. Specifying the protocol and statistical analysis plan before the conclusion of enrollment increases the rigor, reproducibility, and transparency of the trial.

Clinical trial registration: ClinicalTrials.gov; No.: NCT05277896; URL: www.clinicaltrials.gov.