Comparing Effects of Enteral and Parenteral Nutrition in Patients Admitted to Intensive Care Units: A Systematic Review

With regard to critical illness and stress, medication side effects, decreased appetite, and increased nausea and vomiting; patients admitted to intensive care units (ICUs) are at particular risk of malnutrition. Feeding behavior i.e. time and method in these patients has still remained as an unresolved issue. Thus; enteral and parenteral nutrition, with their own benefits and complications, are two commonly used methods for such individuals. The present systematic review was to compare the effects of enteral and parenteral nutrition in patients admitted to ICUs.

This systematic review investigated a total number of 1642 articles on nutrition methods in ICU patients during 2010-2019 using keywords of “enteral nutrition, parenteral nutrition solutions, parenteral nutrition, critical care outcomes, critical illness, intensive care unit, and ICU” in the databases of SID, Iranmedex, MEDLIB-ED, PubMed, Scopus, Medline, Embase, Cochrane, Web of Science, and Google Scholar; and finally, 15 articles were analyzed in relation to the research objectives.

Studies indicated that patient mortality was not different in enteral and parenteral nutrition groups. The incidence rate of infectious complications was also reported higher in parenteral nutrition group. However, there was no significant difference in the incidence rate of infections in studies meeting total standards for parenteral nutrition. Besides, there was no significant difference between the duration of undergoing mechanical ventilation and hospitalization time in both groups. Furthermore, the incidence rate of hypoglycemia was higher in enteral nutrition group; but serum protein levels had much better status compared with those in parenteral nutrition group.

If standards for infusion are observed and provided that rates of infectious complications are reduced, patients can benefit from starting parenteral nutrition immediately after admission to ICUs in the absence of enteral method.