Nephrotic Syndrome

Nephrotic syndrome is a clinical syndrome resulting from increased permeability of the glomerular capillary wall, leading to massive proteinuria, hypoalbuminemia, generalized edema, and hyperlipidemia. The glomerular filtration barrier consists of three layers: fenestrated endothelium, glomerular basement membrane (GBM), and podocyte foot processes with slit diaphragms. Damage to any of these layers (particularly the podocytes) allows large quantities of plasma proteins, primarily albumin, to leak into the urine. When urinary protein loss exceeds the liver's synthetic capacity for albumin (normally 12-14 g/day), serum albumin falls below 3.0 g/dL (hypoalbuminemia). This reduces plasma oncotic pressure, causing fluid to shift from the intravascular space into the interstitial tissues (edema). The liver compensates by increasing synthesis of all proteins, including lipoproteins, leading to hyperlipidemia (elevated total cholesterol, LDL, and triglycerides). Urinary loss of antithrombin III and other anticoagulant proteins creates a hypercoagulable state with high risk for venous thromboembolism (renal vein thrombosis is particularly common). Common causes in adults include minimal change disease, focal segmental glomerulosclerosis (FSGS), membranous nephropathy, and diabetic nephropathy. The practical nurse monitors for edema, proteinuria, fluid balance, and complications of...