NUTRITIONAL THERAPY IN CRITICALLY ILL PATIENTS: A SYSTEMATIC REVIEW OF PROTOCOLS AND CLINICAL OUTCOMES

Abstract

Nutrition therapy is an integral component of care for critically ill patients, although disagreements persist regarding its initiation, route of administration, and calorie and protein targets. This systematic review aimed to identify nutrition therapy protocols used in intensive care units and their associated outcomes. The review followed the PRISMA 2020 recommendations, with searches conducted in PubMed/MEDLINE, Embase, Cochrane Library, SciELO, LILACS, the Virtual Health Library, and CINAHL, covering publications from 2014 to 2026 in Portuguese, English, and Spanish. Risk of bias was assessed using the RoB 2, Newcastle-Ottawa, and AMSTAR 2 tools. The sample comprised 21 studies: ten multicenter randomized clinical trials, seven systematic reviews with meta-analysis, and four observational studies. No large-scale trial demonstrated a reduction in mortality through increased energy or protein provision. Increased caloric density did not alter 90-day mortality, whereas high protein provision did not reduce time to hospital discharge and was associated with poorer quality of life and greater gastrointestinal intolerance. Early calorie and protein restriction in patients with shock reduced the time to readiness for discharge without affecting survival. The route of administration did not alter mortality, although early enteral nutrition in patients with shock increased the incidence of mesenteric ischemia. Brazilian studies indicated frequent inadequate protein provision and an association between nutritional risk and death. The review concludes that current protocols prioritize individualized care, adequate protein provision, and intolerance management.