RESUMEN
Recently, two new methods (total body electrical conductivity [TOBEC] and bioelectrical impedance analysis [BIA]) have become available for the rapid, safe, and convenient estimation of total body water in hospital patients. Despite these clear advantages, the clinical usefulness of the TOBEC and BIA methods in patient diagnosis and care is likely to be restricted by illness-related changes in the hydration of the lean body and in the distribution of water between the intracellular and extracellular water compartments. If these methods can be refined so as to permit their measurement of extracellular water as rapidly as they now measure total body water, the ability of clinicians to assess and monitor the nutritional and metabolic status of their hospital patients will be greatly enhanced.