Do Data Support Nutrition Support? Part II. Enteral Artificial Nutrition

Artificial nutrition is widely advocated as adjunctive care in patients with a variety of underlying diseases. In recent years more emphasis has been placed on delivering it directly into the gastrointestinal tract through tubes in the stomach or proximal small intestine (enteral nutrition). Because the efficacy of any therapeutic intervention is best established by demonstrating it in one or more randomized controlled trials, this review focuses on data from such studies. The specific issue to be assessed is the ability of enteral nutrition to influence the mortality and morbidity of various diseases, a question that was addressed in depth in a recent systematic review. This article presents the highlights of that systematic review and puts it in context with the perspective of a practicing food and nutrition professional. Using established search strategies, 30 randomized controlled trials were identified that compared enteral nutrition to no artificial nutrition. In addition, other randomized controlled trials were identified that did provide some insight into the clinical utility of enteral nutrition. The randomized controlled trials were stratified by the underlying disease state. No high-quality evidence indicated that enteral nutrition had any beneficial effect on clinical outcome. Low-quality evidence, which tends to overestimate the treatment effect, suggested that enteral nutrition may be useful in reducing the incidence of postoperative complications and infection rates in intensive care units, improving mortality in chronic liver disease, and reducing length of stay when provided as trophic feeding to low-birth-weight neonates who are also receiving intravenous artificial nutrition. Enteral nutrition was not helpful when given during the first week to patients with dysphagic strokes. Thus, the randomized controlled trials that have compared enteral nutrition to no artificial nutrition have only found benefit when the methodologic rigor of the studies is inadequate to prevent bias from interfering with the interpretation of the data. No high-quality data are available to prove that enteral nutrition is of benefit.