Timing of Limitations in Life Support in Acute Lung Injury Patients: a Multisite Study*

Objective: Substantial variability exists in the timing of limitations in life support for critically ill patients. Our objective was to investigate how the timing of limitations in life support varies with changes in organ failure status and time since acute lung injury onset.

Design, Setting, And Patients: This evaluation was performed as part of a prospective cohort study evaluating 490 consecutive acute lung injury patients recruited from 11 ICUs at three teaching hospitals in Baltimore, MD.

Interventions: None.

Measurements: The primary exposure was proportion of days without improvement in Sequential Organ Failure Assessment score, evaluated as a daily time-varying exposure. The outcome of interest was a documented limitation in life support defined as any of the following: 1) no cardiopulmonary resuscitation, 2) do not reintubate, 3) no vasopressors, 4) no hemodialysis, 5) do not escalate care, or 6) other limitations (e.g., "comfort care only").

Main Results: For medical ICU patients without improvement in daily Sequential Organ Failure Assessment score, the rate of limitation in life support tripled in the first 3 days after acute lung injury onset, increased again after day 5, and peaked at day 19. Compared with medical ICU patients, surgical ICU patients had a rate of limitations that was significantly lower during the first 5 days after acute lung injury onset. In all patients, more days without improvement in Sequential Organ Failure Assessment scores was associated with limitations in life support, independent of the absolute magnitude of the Sequential Organ Failure Assessment score.

Conclusions: Persistent organ failure is associated with an increase in the rate of limitations in life support independent of the absolute magnitude of Sequential Organ Failure Assessment score, and this association strengthens during the first weeks of treatment. During the first 5 days after acute lung injury onset, limitations were significantly more common in medical ICUs than surgical ICUs.