Purpose: Patients who require mechanical ventilation are at risk of emotional stress because of total dependence on a machine for breathing. The stress may negatively impact ventilator weaning and survival. The purpose of this study was to determine whether depressive disorders in patients being weaned from prolonged mechanical ventilation are linked to weaning failure and decreased survival.
Methods: A prospective study of 478 consecutive patients transferred to a long-term acute care hospital for weaning from prolonged ventilation was undertaken. A clinical psychologist conducted a psychiatric interview to assess for the presence of depressive disorders.
Results: Of the 478 patients, 142 had persistent coma or delirium and were unable to be evaluated for depressive disorders. Of the remaining 336 patients, 142 (42%) were diagnosed with depressive disorders. In multivariate analysis, co-morbidity score [odds ratio (OR), 1.23; P = 0.007], functional dependence before the acute illness (OR, 1.70, P = 0.03) and history of psychiatric disorders (OR, 3.04, P = 0.0001) were independent predictors of depressive disorders. The rate of weaning failure was higher in patients with depressive disorders than in those without such disorders (61 vs. 33%, P = 0.0001), as was mortality (24 vs. 10%, P = 0.0008). The presence of depressive disorders was independently associated with mortality (OR, 4.3; P = 0.0002); age (OR, 1.06; P = 0.001) and co-morbidity score (OR, 1.24; P = 0.02) also predicted mortality.
Conclusion: Depressive disorders were diagnosed in 42% of patients who were being weaned from prolonged ventilation. Patients with depressive disorders were more likely to experience weaning failure and death.