Treatment of Cor Pulmonale
Oxygen therapy is the cornerstone and only proven treatment for cor pulmonale, as it is the only intervention that specifically addresses hypoxic pulmonary vasoconstriction and has demonstrated mortality benefit. 1
Primary Treatment: Long-Term Oxygen Therapy (LTOT)
Oxygen supplementation is life-saving and increases life expectancy in patients with chronic respiratory failure and cor pulmonale. 1
Indications for LTOT:
- PaO₂ ≤7.3 kPa (55 mmHg) during a stable 3-4 week period despite optimal therapy, with or without hypercapnia 1
- PaO₂ 7.3-7.9 kPa (55-59 mmHg) with evidence of cor pulmonale or polycythemia 1
- Oxygen is the only agent that produces specific vasodilation for pulmonary hypertension induced by hypoxic vasoconstriction 1
Oxygen Administration Goals:
- Raise SaO₂ to ≥90% and/or PaO₂ to ≥8.0 kPa (60 mmHg) 1
- Avoid elevating PaCO₂ by >1.3 kPa (10 mmHg) or lowering pH to <7.25 1
- Start at low dose (24% by Venturi mask or 1-2 L/min by nasal cannulae) and titrate based on arterial blood gas monitoring 1
Adjunctive Pharmacologic Management
Diuretics for Fluid Management:
- Diuretics can reduce peripheral edema associated with right ventricular failure 1
- Use carefully to avoid reducing cardiac output and renal perfusion 1
- Monitor closely for electrolyte imbalance, particularly in hypoxemic and hypercapnic patients 1
Critical Medication Precautions:
- The hypoxic myocardium is especially sensitive to digoxin and aminophylline - use with extreme caution 1
- Avoid pulmonary vasodilators - their use is limited by systemic circulatory effects, and there is no evidence they benefit COPD patients with pulmonary hypertension 1
- Respiratory stimulants are not recommended - no evidence of improved survival, and almitrine causes peripheral neuropathy 1
Treatment of Underlying COPD
Bronchodilator Optimization:
- Maximize bronchodilator therapy with combination β₂-agonist and anticholinergic agents in severe disease 1
- Optimize inhaler technique and delivery device selection 1
Corticosteroid Trial:
- Consider corticosteroid trial in moderate to severe COPD - 10-20% show objective improvement 1
- Use 30 mg prednisolone daily for two weeks, assessing for FEV₁ increase of ≥10% predicted and absolute increase ≥200 mL 1
- If beneficial, reduce to lowest effective dose due to significant side effects (osteoporosis, muscle weakness, hypertension, diabetes) 1
Management of Acute Exacerbations
When cor pulmonale worsens during exacerbations:
- Increase bronchodilator dose/frequency immediately 2
- Initiate empirical antibiotics for 7-14 days if sputum becomes purulent (amoxicillin, tetracycline derivatives, or amoxicillin/clavulanic acid) 2
- Short course of systemic corticosteroids 2
- Oxygen therapy - essential during acute exacerbations 1
- Consider noninvasive ventilation over respiratory stimulants like doxapram 1
Critical Pitfalls to Avoid
- Never use sedatives or benzodiazepines in advanced COPD with cor pulmonale - risk of respiratory depression is unacceptable 3
- Avoid beta-blocking agents (including eyedrop formulations) - can worsen bronchospasm 1
- Do not use mucolytics routinely - no evidence supports their use and they are not recommended 1
- Prophylactic antibiotics have no role in stable cor pulmonale 1
Monitoring Requirements
- Arterial blood gases are essential if FEV₁ <50% predicted or clinical signs of respiratory failure/cor pulmonale 2
- Chest radiograph to assess for cor pulmonale (right descending pulmonary artery >16mm suggests pulmonary hypertension) 2
- Monitor for signs of right ventricular failure: peripheral edema, raised jugular venous pressure, hepatic enlargement 1
Prognosis and Advanced Considerations
- Development of pulmonary hypertension and right ventricular failure signals poor prognosis 4
- Lung or heart-lung transplantation may be considered when medical therapies fail in selected patients 5
- Treatment is primarily directed at the underlying pulmonary disorder rather than right ventricular failure per se 5