June 2007: Do Data Support Nutrition Support? Part I: Intravenous Nutrition

Parenteral nutrition has long been utilized as a method of nutrition support for malnourished patients or those with underlying diseases. This form of nutrition support is based on expert opinion and has been ardently implemented ever since techniques were developed for delivering nutrition support via central venous access. For over seventy years, we have known that malnourished patients have poorer outcomes than nourished patients with the same disease state. Moreover, knowing that prolonged deprivation of adequate nutrition leads to malnutrition, it seems more than logical to assume that artificial nutrition would improve the current state of a malnourished patient. It is important, however, to note that this association between malnutrition and poor outcome is merely that—an association—and that providing artificial nutrition may not necessarily result in improved clinical outcome as it is possible there may be other underlying problems contributing to the patient’s condition. Due to limited resources for health care, it is important to use them where they will be most effective. As medical professionals, we typically use evidence from medical literature to make decisions regarding resource utilization, but oftentimes this evidence is inconclusive or conflicts with other studies, making it difficult to draw a strong conclusion.

A meta-analysis of randomized controlled trials was performed to test the efficacy of nutrition support by comparing one of two forms of nutrition therapy: parenteral nutrition or protein-sparing therapy with no type of artificial nutrition beyond regular food and dextrose (no nutrition support). The majority of the randomized controlled trials failed to demonstrate that parenteral nutrition had any significant effect on clinical outcome, which included mortality, morbidity (total/infectious complications), and duration of hospitalization. There were some studies that found a benefit to parenteral nutrition, but it is important to realize these were low-quality randomized controlled trials. There were some conflicting findings in other types of patients, as is the case with many types of studies, and parenteral nutrition was actually found to be harmful when provided to some subgroups of patients.

The additional articles concluded that surgery and medical ICU patients were substantially underfed during their stay in the ICU when compared with RD recommendations (50% of goal met in surgical ICU and 56% of goal met in medical ICU). However, delivery of full nutrient needs in the ICU was associated with a longer length of stay in both the hospital and ICU. Moreover, dietitians were significantly more likely to endorse the statement “when in doubt, feed” compared to nurses. These feeding-related philosophical differences between dietitians and other hospital staff, such as nurses or even doctors, are due to differences in education, training, and roles in health care, among other factors. However, these differences in beliefs may affect consistent and quality care in patients.

JADA Continuing Education Research Article:
Koretz RL. Do data support nutrition support? Part I: Intravenous nutrition. J Am Diet Assoc. 2007; 107: 988-996.

Additional Articles:
Hise ME, Halterman K, Gajewski BJ, Parkhurst M, Moncure M, & Brown JC. Feeding practices of severely ill intensive care unit patients: An evaluation of energy sources and clinical outcomes. J Am Diet Assoc. 2007; 107:458-465.

Enrione EB & Chutkan S. Preferences of registered dietitians and nurses recommending artificial nutrition and hydration for elderly patients J Am Diet Assoc. 2007; 107:416-421.

Articles and the JADA Continuing Education Questionnaire can be found at www.eatright.org.