Outcome of patients undergoing prolonged mechanical ventilation after critical illness*

Objective: To examine the longitudinal outcome of a cohort of mechanically ventilated patients admitted to an acute care respiratory unit after critical illness. Design, Setting, and Patients: Prospective, observational study of 210 consecutive patients admitted to a respiratory unit of an acute, tertiary care university hospital, who had an acute critical illness with respiratory failure. The study was powered to develop multivariate regression models to investigate the relationship between patient characteristics and a) liberation from mechanical ventilation and b) survival. Interventions: None. Measurements and Main Results: The median time to liberation from mechanical ventilation after respiratory unit admission was 14 days (interquartile range, 6–51). A total of 146 patients (69%) were off mechanical ventilation at 6 months, and 123 patients (61%) were alive at 1 yr. Patients who did not come off mechanical ventilation in the respiratory unit were seven times more likely to die within a year than those who did (odds ratio, 6.55; 95% confidence intervals, 4.04–10.63; p < .001). At least 75% of deaths occurred by consensual withdrawal of life support. Patient activity of daily living scores (0–100 scale) increased progressively from hospital discharge (24 ± 6) through 3 (54 ± 21) and 6 months (64 ± 22) (p < .001). The median cost of hospitalization for all study patients was $149,624 (interquartile range, $102,540–225,843). Conclusions: The majority of patients requiring prolonged mechanical ventilation in a respiratory unit after acute critical illness are liberated from mechanical ventilation, survive, and have a steady improvement in the activity of daily living during the first 6 months after discharge. However, a substantial fraction of these patients does not wean from mechanical ventilation and dies from consensual withdrawal of life support after a prolonged and costly hospital stay.