Onkotikus

Onkotikus is a term used in medical literature to denote concepts related to oncotic pressure, the osmotic pressure exerted by plasma proteins in the blood. The dominant contributor is albumin, with minor contributions from other proteins such as globulins. Oncotic pressure draws water from the interstitial space back into capillaries, helping to maintain intravascular volume and to counterbalance hydrostatic forces along the capillary walls.

Physiologically, changes in oncotic pressure influence fluid distribution between blood vessels and surrounding tissues. A decrease in oncotic pressure—commonly due to hypoalbuminemia in liver disease, malnutrition, nephrotic syndrome, or protein loss—reduces the force drawing water into the vessels and favors edema and effusions. Increases in oncotic pressure are less common and typically occur only with markedly elevated protein levels or administration of certain plasma expanders.

Clinically, oncotic pressure is often estimated indirectly via serum albumin concentration, although direct measurement of colloid osmotic pressure can be performed with specialized equipment. It is a component in assessment of fluid therapy and edema management and is considered alongside hydrostatic pressures in discussions of Starling forces and capillary fluid exchange.

Related terms include colloid osmotic pressure, oncotic pressure, and albumin; it is important in fields such as physiology, nephrology, and hepatology.