Cardiogenic pulmonary oedema is fluid accumulation in the alveoli and lung interstitium due to heart failure. It is characterized by increased pulmonary capillary wedge pressure (PCWP > 10 mmHg) secondary to ineffective lung filling or pumping.
Classification of pulmonary oedema
| Classification | Causes |
|---|---|
| Cardiogenic pulmonary oedema | Congestive heart failure, valvular disease (aortic and mitral disease), arrhythmia, myocarditis, and cardiomyopathy |
| Non-cardiogenic pulmonary oedema | Lymphatic obstruction, excess volume administration, hypoalbuminaemia, and lung injury |
- Pathophysiology
- Increased venous pressure → increased capillary pressure → interstitial oedema → alveolar flooding
- Tachypnoea → respiratory alkalosis
- Respiratory fatigue → respiratory acidosis
- Signs and symptoms
- Dyspnea
- Cough
- Pink frothy sputum
- Anxiety
- Chest Pain
- Tachypnea
- Tachycardia
- Visible distress
- Crackles
- Wheezing
- S3 and S4 murmur
- Cool extremities
- Skin mottling
- Investigations
- Laboratory tests
- Complete blood count
- U/E/Cs
- Liver Function Tests
- BNP
- Arterial blood gases
- Chest X-ray: This is the best initial test in a patient who does not need to be intubated.
- Alveolar infiltrates – “Bat’s wings” oedema:
- Kerley B lines – fluid infiltration into the pulmonary interstitium
- Oedema is prominent in the lower lung fields (dependent oedema)
- Hilar obscurity
- Blunted costophrenic angle (pleural effusion)
- Cardiomegaly – in chronic conditions, e.g., heart failure and chronic valvular heart disease
- A normal cardiac silhouette may be present
- Echocardiogram
- Electrocardiogram
- PCWP (Swan-Ganz catheterization)
- Laboratory tests
- Treatment
- Upright positioning
- Oxygen
- Nasal → mask → CPAP → intubation
- Intravenous loop diuretics
- Nitrates or nitroprusside to reduce preload/afterload
- Identify and address the underlying cause
- For severe cases:
- Ionotropes
- Vasopressors
- Mechanical support (intra-aortic balloon pump, ventricular assist device, or ECMO)