Determinants of weaning and survival among patients with COPD who require mechanical ventilation for acute respiratory failure.

The decision to institute MV in patients with COPD and ARF is difficult because the risk of complications is high and the long-term prognosis is poor. We reviewed our experience with 95 COPD patients with ARF requiring MV. Fifty-five patients required MV for more than two weeks, 72 were weaned successfully, and 59 died within one year of follow-up. Survival was associated with premorbid level of activity (p less than .001), FEV1 (p less than .01), serum albumin level (p less than .05), and severity of dyspnea (p less than .01). Cor pulmonale on ECG, premorbid hypercarbia, and history of left ventricular failure were also more common among those who died. Weaning from MV was associated with premorbid level of activity (p less than .001), FEV1 (p less than .001), albumin level (p less than .05), and negative inspiratory pressure (p less than .001) and respiratory rate during T-piece trial (p less than .01). The duration of intubation was associated only with premorbid level of activity (p less than .01). Predictive models for the weaning success and the one-year survival were developed.