Treatment of Underlying Etiology
- Anticoagulation or vena caval interruption are effective for thromboembolic
- CPAP or tracheostomy can be used for obstructive sleep apnea, and correction of
cardiac abnormalities is effective if the pulmonary vascular resistance is not
- Medical therapy is aimed primarily at decreasing right sided afterload. This can
be done most effectively with oxygen via reversal of hypoxic pulmonary vasoconstriction.
Indeed, 2 large studies of patients with chronic hypoxia (SaO2<90%) and cor pulmonale secondary to COPD demonstrated marked survival benefits with long term oxygen therapy.
- Vasodilating agents used in
left heart failure are generally ineffective at decreasing right sided afterload as
systemic hypotension is usually encountered before significant decreases in pulmonary
vascular resistance are achieved. One clear exception to this is inhaled nitric oxide. The
rapid metabolism of this drug prevents systemic vasodilation and hypotension. Furthermore
its distribution solely to ventilated regions prevents the worsened hypoxemia due to
impaired V/Q mismatching encountered with systemic vasodilators. Investigation in this
field is active.
- Peripheral edema and ascites due to R heart failure can be treated with
diuretics. This must be done with care as decreased right ventricular filling can be
associated with a catastrophic fall in cardiac output.
- Digoxin is not effective for treating R heart failure.
- Lung transplantation should be considered for patients with end stage COPD,
fibrotic lung diseases and primary pulmonary hypertension who have severe symptoms despite
maximal medical therapy. Dramatic reversals in pulmonary hypertension and clinical
symptoms are seen with this procedure, however, it carries the side effects of long term