Informed consent in the critically ill: A two-step approach incorporating delirium screening

Objectives. Sedation-agitation and delirium are common in critically ill patients and may be important barriers to informed consent. We describe a two-step process for informed consent and evaluate the natural history of patients' competency by repeated application of this process during their hospitalization. Design: Observational study. Setting: Nine intensive care units (ICUs) in three teaching hospitals in Baltimore, MD. Patients: One hundred fifty patients with acute lung injury. Interventions: Two-step process involving objective evaluation with Richmond Agitation-Sedation Scale (RASS) and Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) (step 1), followed by traditional assessment for competency (step 2) in those patients passing step 1. Measurements and Main Results: RASS and CAM-ICU assessments (during ICU stay, at consent and hospital discharge); cumulative proportion of patients providing consent at extubation and at ICU and hospital discharge. Of 150 patients, 86 (57%) survived and 77 (90% of survivors) provided consent. Patients were delirious/deeply sedated in 89% of daily assessments during mechanical ventilation. By extubation, 31 (44%) patients passed step 1 and 8 (11%) passed step 2 and were consented. By ICU and hospital discharge, these numbers were 50 (58%) and 18 (21%), and 81 (94%) and 67 (78%), respectively. The median (interquartile range) time to patient consent after acute lung injury diagnosis was 15 (9-28) days. Conclusions: More than three fourths of critically ill patients are unable to provide informed consent throughout their ICU stay, even after extubation. Sedation-agitation and delirium are common barriers to consent. A two-step consent process, using validated instruments for sedation-agitation and delirium, provides a means of rapidly screening critically ill patients before a more detailed traditional assessment of competency is conducted.