Pulmonary edema

Pulmonary edema (British English: oedema), also known as pulmonary congestion, is excessive fluid accumulation in the tissue or air spaces (usually alveoli) of the lungs. This leads to impaired gas exchange, most often leading to shortness of breath (dyspnea) which can progress to hypoxemia and respiratory failure. Pulmonary edema has multiple causes and is traditionally classified as cardiogenic (caused by the heart) or noncardiogenic (all other types not caused by the heart). Various laboratory tests (CBC, troponin, BNP, etc.) and imaging studies (chest x-ray, CT scan, ultrasound) are often used to diagnose and classify the cause of pulmonary edema. Treatment is focused on three aspects: improving respiratory function, treating the underlying cause, and preventing further damage and allow full recovery to the lung. Pulmonary edema can cause permanent organ damage, and when sudden (acute), can lead to respiratory failure or cardiac arrest due to hypoxia. The term edema is from the Greek οἴδημα (oidēma, "swelling"), from οἰδέω (oidéō, "(I) swell").