Pulmonary edema is one of the most severe, not often fatal complications of a number of diseases associated with excessive sweating of tissue fluid on the surface of the diffuse alveolar-capillary membrane of the lungs.
Varieties of pulmonary edema
There are hydrostatic and membranogenic pulmonary edema, the origin of which is different.
Hydrostatic pulmonary edema occurs in diseases in which intracapillary hydrostatic blood pressure rises to 7-10 mm Hg. Art., which leads to the release of the liquid part of the blood into the interstitium in an amount exceeding the likelihood of its removal through the lymphatic tract.
Membranogenic pulmonary edema develops in cases of primary increase in pulmonary capillary permeability, which can occur in various syndromes.
The reasons
The essence of the development of pulmonary edema lies in the increased influx of fluid into the lung tissue, which is not balanced by its reabsorption into the vascular bed. At the same time, protein blood transudate and pulmonary surfactant against such a background easily pass into the lumen of the alveoli, mix with air there and form a stable foam that fills the airways, preventing oxygen from entering the gas exchange zone of the lungs and to the alveolar-capillary membrane.
The most common edema occurs in therapeutic practice. The occurrence of pulmonary edema is promoted primarily by:
- diseases of the cardiovascular system: atherosclerotic cardiosclerosis, postinfarction cardiosclerosis, hypertension of any etiology, acute myocardial infarction;
- damage to the heart and aorta: aortic valve insufficiency, aortic aneurysm; rheumatic nature: acute rheumatic cardiomitral, aortic heart disease, less often subacute and septic endocarditis;
- and in childhood and adolescence – congenital anomalies of the heart and blood vessels: coarctation of the aorta, non-closure of the ductus arteriosus, defect of the interatrial or interventricular septum, anastomosis of the pulmonary veins with the left atrium, aortic-culmonal shunts.
Main symptoms
Harbingers of worn out forms: increased (appearance) of shortness of breath, orthopnea. Choking, coughing, or only rawness behind the sternum with little exertion or when moving to a horizontal position. Usually – weakened breathing and meager wheezing below the shoulder blades.