Transudativ

Transudativ, or transudate, is a medical term describing a type of fluid that accumulates in body cavities or spaces due to systemic factors rather than local inflammation. Transudates are typically low in protein and lactate dehydrogenase (LDH) and arise when hydrostatic pressure increases or oncotic pressure decreases, leading to net fluid movement from the vasculature into serous cavities. They are contrasted with exudates, which result from inflammation or infection and usually have higher protein and LDH levels.

In clinical practice, transudates are distinguished from exudates using specific criteria. For pleural effusions, Light’s criteria define a transudate as an effusion with a protein ratio (effusion/serum) <0.5, an LDH ratio <0.6, and LDH not exceeding two-thirds of the upper limit of normal. For ascites, a serum-ascites albumin gradient (SAAG) ≥1.1 g/dL indicates a transudative process driven by portal hypertension; a SAAG <1.1 g/dL suggests an exudative etiology.

Common causes of transudative effusions include congestive heart failure and other forms of fluid overload, cirrhosis with ascites, nephrotic syndrome, and hypoalbuminemia from malnutrition or renal loss. Less frequently, hypoalbuminemia from protein-losing enteropathy or severe systemic illness can produce transudates.

Management focuses on treating the underlying condition. This may involve diuretics and salt restriction for heart failure–related effusions, management of liver disease for cirrhosis-related ascites, and therapy for nephrotic syndrome. Large-volume fluid accumulations may require drainage, with considerations for albumin replacement in certain settings. Prognosis largely reflects the underlying disease rather than the transudate itself.