Resumo (EN)
This review aims to raise the main aspects about the use of bioelectrical impedance in critically patients. The search for articles was based on the virtual databases indexed to the Virtual Health Library (Lilacs, Medline and Scielo) and PubMed, and the inclusion criteria used were articles published in national and international journals in English, Portuguese and Spanish. Standard gold techniques for measuring body composition and total body volume of water require special equipment and can not be used for daily measurements at the bedside. Bioelectrical Impedance is a simple, non-invasive, fast, portable, reproducible and convenient method for measuring body composition and fluid distribution. Measurement of the volume of intra- and extracellular fluids by bioimpedance has a great potential in critically ill patients. Data available in the literature suggest that bioimpedance can be used as a prognostic indicator in some clinical conditions, since it can detect changes within a few hours after acute events involving inflammation and stress, indicate functional alterations in the cell membrane and changes in the fluid distribution of the compartments intra and extracellular.