Nutritional assessment of the severely ill patient.

Considering the importance and the difficulties inherent to nutritional state assessment, as well as the results interpretation and the inexistence of specific and validated guidelines related to applied methods to the severely ill patient, the present revision aims to contribute to the analysis and recommendation of efficient methods, which are suitable to use and reliable in terms of interpretation in the context of the severely ill patient. The presence of edema and unspecific alterations in the plasmatic concentrations of proteins; altered anthropometrics variables reflecting more the rearrangement of the total body water than the nutritional state changes; inconclusive studies with electric bioimpedance; absence of data related to the application of the global subjective assessment to severely ill patients; altered biochemical markers as a consequence of the metabolic changes that, among others, indicate several method limitations to these patients. Notwithstanding the lack of studies to validate the various methods, recommendations based on clinical evidences, observation and physiopathology alterations are available. Independent from the methods, clinical observation by the health staff at all stages is mandatory. It is crucial to dedicate more efforts to identify methods and their specificity to detection, risk assessment or monitoring.