Inclusion Criteria:  Patient is admitted or scheduled for admission to a participating study hospital Planned procedure is tracheal intubation and planned operator is a provider expected to routinely perform endotracheal intubation in the participating unit Critical illness (i.e. life-threatening condition with intubation required for cardiorespiratory failure or neurological impairment) Administration of sedation (with or without neuromuscular blockade) is planned Age 18 years or older  Exclusion Criteria:  Operator feels vasopressor support is absolutely indicated or contraindicated in the patient Urgency of intubation precludes safe performance of study procedures Intubation performed during cardiopulmonary resuscitation of a patient in cardiac arrest Pregnant or suspected pregnancy