ABSTRACT
An exacerbation of chronic obstructive pulmonary disease (COPD) of sufficient
severity to necessitate hospital admission carries a poor prognosis, with a reported
mortality of between 6 and 26% (1, 2). However, the outcome from invasive
mechanical ventilation (IMV) in patients with COPD is disappointing, both in the
short term, with reported survivals of between 20 and 50% (3), and also after
hospital discharge. Studies report 1-year survivals of between 25 and 54% (4-8).
Patients with COPD who require IMV may subsequently prove difficult to wean
from assisted ventilation. A number of studies have shown an incidence of
prolonged need for ITU ventilation in between 5 to 13% of all ventilated patients
(9), and these patients have a particularly poor prognosis with a hospital mortality of
50% (10). A diagnosis of COPD has been shown to be a strong predictor of weaning
difficulty (10, 11).
