The role of the glycocalyx in transvascular fluid shifts: GLYCOCALYX AND FLUID SHIFTS

SUMMARY Perioperative fluid management and fluid shifting have been main topics of debate in the recent years. Liberal fluid application is still a common practice and fluid overload believed to be a minor problem. Recent studies, however, have shown that liberal fluid management facilitates fluid shifts into the interstitial space especially in the context of major abdominal surgery. Consequently, the integrity of the vascular barrier is a rediscovered target of research. The endothelial glycocalyx, which covers the endothelial cells on the luminal side of every healthy vessel, plays a key role concerning the barrier properties of healthy blood vessels. Together with bound plasma proteins the glycocalyx forms the endothelial surface layer with a thickness of about 1 µm. With these packed proteins, this layer has its own colloid osmotic force. Damage of the endothelial glycocalyx can lead to protein extravasation and tissue edema. The endothelial glycocalyx is also important concerning leukocyte and platelet adhesion and shear-stressed nitric oxide-release and therefore, very probably, with regard to the pathophysiology of diseases like sepsis and ischemia/reperfusion injury. The purpose of this review is to elucidate the physiological and functional impact of the endothelial glycocalyx in transvascular fluid shifts.