Water physiology in burn victims

Sammanfattning: Patients who sustain a burn injury of more than 20 - 30 % TBSA will, if untreated, develop burn shock within a couple of hours. Flcid is lost fi·om the vascular compartment due to suction from the interstitium of the wound and due to a generalised increase in vascular permeability. To prevent bum shock intravenous fluids are given during the first two days after a bum in order to ensure adequate organ perfusion. Although organ perfusion will be improved when blood volume is restored, the fluid provided will add to the continuing leak into the tissues. With fluid treatment the patient survives the acute stage, but the resulting oedema interferes with the healing of the burn wound and partially damaged skin may be further compromised.To describe, follow and understand the development of the general oedema in burn injured patients we used four different techniques. Ethanol dilution was used for measurement of total body water (TBW), iohexol dilution in order to estimate extracellular volume (ECV), bioimpedance analysis (BIA) to register TBW as well as electrical membrane properties and the impression method (IM) for the measurement of visco-elastic properties in non-burned tissues. In order to further examine the non-invasive techniques (BIA and IM) these were used in patients subjected to haemodialysis.The excess fluid was found to be accumulated in the extracellular space. Interesting alterations in the visco-clastic properties of the skin and cellular electrical membrane properties could also be detected. These alterations were not related to the actual tluid volume in the tissues. Instead, they were related to changes in the fluid equilibrium of the tissues. Still, one week postbum an excess of tissue fluid, altered cellular electrical membrane properties and changed visco-elastic properties of the skin remained.Albumin supplementation did not influence the amount or distribution of the excess tissue fluid, measured with dilution techniques.