Obtaining informed consent in acute trauma patients is often impossible, forcing investigators to abandon important projects. To better understand the likelihood of—and barriers to—informed consent in trauma patients, we evaluated when and how consent is possible in acutely injured patients.

Over a 7-month period, at a large, urban, adult Level I trauma center, we prospectively assessed each patient’s ability to give hypothetical informed consent. Patients were considered consentable when they were alert, unintoxicated, and stable, with no prohibitive language barrier, or when a proxy (first-degree relative) was available. When consent was not feasible on arrival, we documented the reason and the time at which consent became possible, either by the patient or proxy.

Of 1,328 consecutive trauma patients, 1,020 (77%) were candidates for consent (personal or proxy) within 30 minutes of arrival. Twenty-five percent of patients with hypotension in the resuscitation area were consentable, as were 31% of severely injured (Injury Severity Score>24) patients. Eight hours after injury, 88% of all patients were consentable, as were 60% of severely injured patients and 36% of patients with initial hypotension. Primary barriers to consent included brain injury or unspecified alteration in awareness (41%), intoxication (28%), shock (26%), language barrier (2%), or medication (3%).

Although an overall majority of trauma patients are candidates for early informed consent, the likelihood of early consent is substantially lower in patients with severe injury or shock. Alternatives to individual informed consent may be necessary to advance the early care of acutely, severely injured patients.