Pulmonary Oedema

Definition:

Collection of fluid in lung interstitial space and/or alveolar spaces. Characterised by extreme breathlessness.

Causes:

Heart failure.

Pathophysiology:

Pressure above 20mmHg causes fluid filtration from capillaries into interstitial space. Further accumulation of fluid disrupts intercellular membranes, leading to collection of fluid in alveolar spaces.

Signs and symptoms:

Acutely breathlessness, wheezing, anxiety and profuse sweating. Cough productive of frothy, blood-tinged sputum. Tachypnoeic with peripheral circulatory shutdown. Tachycardia, raised venous pressure and gallop rhythm. Crackles and wheezes are heard throughout the chest.

Investigations:

CXR - diffuse haziness, owing to alveolar fluid and lines of interstitial oedema. Can be unilateral, giving the appearance of a tumour that disappears on treatment.

Management:

Place in sitting position, high-concentration oxygen/ventilation. Intravenous diuretics, morphine, venous dilators, bronchodilators.

Prognosis:

Acute emergency.