Pulmonary edema is fluid accumulation within the lungs, usually due to imbalanceof Starling forces or endothelial injury.
· Pulmonary edema due to increased hydrostatic pressure can be seen in left-sided heart failure, mitral valve stenosis, high altitude pulmonary edema, and fluid overload.
· Pulmonary edema due to decreased oncotic pressure can be seen in nephrotic syndrome and liver disease.
· Pulmonary edema due to increased capillary permeability can be due to infections, drugs (bleomycin, heroin), shock, and radiation.
The pathology grossly shows wet, heavy lungs (usually worse in lower lobes), while microscopic examination shows intra-alveolar fluid, engorged capillaries, and hemosiderin-laden macrophages (heart-failure cells).
Pulmonary hypertension is increased pulmonary artery pressure, usually due toincreased vascular resistance or blood flow.
The etiology varies and can include chronic obstructive pulmonary disease and interstitial disease (hypoxic vasoconstriction); multiple ongoing pulmonary emboli; mitral stenosis and left heart failure; congenital heart disease with left to right shunts (atrial septal defect, ventricular septal defect, patent ductus arteriosus); and primary (idiopathic) pulmonary hypertension, typically in young women.
The pathology includes pulmonary artery atherosclerosis, small artery medial hyper-trophy and intimal fibrosis, and plexogenic pulmonary arteriopathy. Pulmonary hypertension may also damage the heart, leading to right ventricular hypertrophy and then failure (cor pulmonale).