Chapter 9 Acute pulmonary oedema
Decompensated heart failure, or acute pulmonary oedema (APO), now accounts for 1% of emergency department visits, with a 16% in-hospital mortality for those admitted with frank pulmonary oedema and an overall 50% five-year mortality.
PATHOPHYSIOLOGY
Acute pulmonary oedema may be divided into cardiogenic and non-cardiogenic causes.
Acute cardiogenic pulmonary oedema
APO may develop out of the blue, or be precipitated in patients with existing heart disease as a result of an acute cause such as ischaemia, an arrhythmia or medication change. Table 9.1 gives the causes of cardiogenic pulmonary oedema.
Precipitating factors |
Non-cardiogenic pulmonary oedema
• increased capillary permeability in acute respiratory distress syndrome (ARDS), septicaemia, aspiration of gastric contents, inhaled toxins, pancreatitis, uraemia or near drowning
• mixed or unknown causes such as neurogenic pulmonary oedema, high-altitude pulmonary oedema (HAPE), heroin overdose, smoking freebase cocaine, eclampsia, post lung re-expansion and post pulmonary embolism
• decreased oncotic pressure such as in hypoalbuminaemia, usually in combination with another cause.