Inclusion Criteria:

• * Patient is critically ill and undergoing emergency tracheal intubation with sedation in an enrolling unit
• * Planned procedure is orotracheal intubation using a laryngoscope
• * Planned operator is a clinician expected to routinely perform tracheal intubation in the participating unit

Exclusion Criteria:

• * Patient is known to be less than 18 years old
• * Patient is known to be pregnant
• * Patient is known to be a prisoner
• * Patient is known to have an allergy to ketamine or etomidate
• * Patient is presenting to the emergency department with a primary diagnosis of trauma
• * Patient or LAR declines participation during pre-enrollment opt-out conversation or by wearing opt-out bracelet for the RSI trial
• * Clinician feels ketamine is required or contraindicated for the optimal care of the patient
• * Clinician feels etomidate is required or contraindicated for the optimal care of the patient
• * Clinician feels an induction medication other than ketamine or etomidate is required for the optimal care of the patient
• * Immediate need for intubation precludes safe performance of study procedures