There are
persistent symptoms of cough, expectoration, wheezing
and progressive dyspnoea, which is further accentuated
by static and dynamic hyperinflation of lungs. As the
disease advances, ventilation/perfusion mismatch
results in hypoxaemia, respiratory acidosis, pulmonary
hypertension and heart failure, culminating in death.1,2
COPD is also complicated by profound systemic
effects.3-5 High levels of circulating proinflammatory
cytokines produce a chronic catabolic state in 20%-40%
patients, resulting in weight loss, skeletal muscle wasting
and chronic fatigue; a low body mass index (BMI; Kg/m2
)
is an independent predictor of mortality. Deconditioning
and weakness of respiratory muscles adversely affect
pulmonary disability and promote respiratory failure.