How to Feed the Critically Ill—A Review

Abstract

Number of recently published studies on nutritional support in the intensive care unit (ICU) have resulted in a paradigm shift of clinical practices. This review summarises the latest evidence in four main topics in the ICU, namely: (1) function of validated nutrition screening/assessment tools, (2) types and validity of body composition measurements, (3) optimal energy and protein goals, and (4) delivery methods. Recent studies that investigated the above aims were outlined and discussed. In addition, recent guidelines were also compared to highlight the similarities and differences in their approach to the nutrition support of critically ill patients. Regardless of nutritional status and body composition, all patients with >48 hours of ICU stay are at nutrition risk and should receive individualised nutrition support. Although a recent trial did not demonstrate an advantage of indirect calorimetry over predictive equations, it was recommended that indirect calorimetry be used to set energy targets with better accuracy. Initiation of enteral nutrition (EN) within 24-48 hours was shown to be associated with improved clinical outcomes. The energy and protein goals should be achieved gradually over the first week of ICU stay. This practice should be protocolised and regularly audited as critically ill patients receive only part of their energy and protein goals. Metabolic demands of critically ill patients can be variable and nutrition support should be tailored to each patient. Given that many nutrition studies are on-going, we anticipate improvements in the individualisation of nutrition support in the near future.