Abstract
In acutely ill patients, disturbances of circulating blood volume and water homeostasis are frequently encountered. In order to choose adequate treatment strategy a well based diagnostics of these disturbance sis necessary, because fluid therapy possess the potential not only to help but also to worsen patient's state.
Currently we have at hand several possibilities to diagnose hypovolemia or hypervolemia: besides standard clinical assessment novel approaches as dedicated laboratory markers or sonography. Tests of fluid responsiveness are other mean how to ensure that the acutely ill patient will receive just the right amount of fluids.
In this review article we will present the current view of the circulating blood volume pathophysiology as well as contemporary diagnostic tools.