Fluid compartments#Third spacing

As a third space, a hypothetical space is described in the body in infusion therapy, the loss of blood plasma is to explain in the framework of large operations. A standard definition does not exist.

In major surgery, particularly abdominal surgery, patients often have an unexplained loss of volume that needs to be replaced with infusion solutions, to keep the circuit stable. It is a shift in the body that can be detected as the weight increase due to the additional amount of infusion, which may be several kilograms in the adult. To explain this demand despite positive fluid balance in the past, the concept of a shift in the third room was postulated.

This third area has so far been neither reliable nor quantitatively detected localized. As a possible anatomical segregation rooms the urine -producing system, the subarachnoid space, secretions in the gastrointestinal tract, peritoneum (ascites ) and the chamber of the eye have been proposed (increase in transcellular fluid). As a so-called non - anatomical proportion edema of the connective tissue ( interstitial) are described. For this part, a separation is postulated from functional, thus participating in the exchange of extracellular fluid.

Due to the current data must be assumed that the most likely assume that a third space does not exist in the sense of infusion therapy. In the liquid surroundings, it is likely to be a shift from the vascular system ( intravascular compartment, the intravascular space ) into the connective tissue (interstitial compartment, extravascular ), ie within the extracellular space. There may be the underlying damage to the glycocalyx of the vessel walls, one consisting of carbohydrates and protein barrier which is attached to the endothelium.