'Immunonutrition' Ill-Advised for ICU Patients on Feeding Tube, Study Says
TUESDAY, Aug. 5, 2014 -- Enriching the feeding-tube nutrition of intensive care patients on ventilators with agents that boost the immune system might cause more harm than good, researchers say.
This type of supplementation doesn't reduce risk of infection and could be associated with a higher risk of death, the researchers reported in the Aug. 6 issue of the Journal of the American Medical Association.
"These findings do not support the use of high-protein enteral nutrition [via feeding tube] enriched with immune-modulating nutrients in these patients," the study's authors wrote.
The results from this and other studies should discourage routine prescription of immunonutrition for critically ill patients outside the scope of well-designed randomized clinical trials, Dr. Todd Rice, of the Vanderbilt University School of Medicine, Nashville, Tenn., said in an accompanying journal editorial.
Some previous studies suggested that providing ICU patients with immune system-boosting nutrients, such as glutamine and omega-3 fatty acids, through feeding tubes is linked with fewer infections and faster recovery from critical illness compared with standard nutrition. But these findings remain the subject of debate among doctors.
To further investigate this issue, the researchers randomly assigned 301 adult ICU patients who were expected to need a feeding tube and a ventilator for more than 72 hours either the immune-boosting nutrients or standard high-protein nutrition. The patients received care in 14 different ICUs in the Netherlands, Germany, France and Belgium. Immune-boosting nutrition was given to half the patients, and the others received the standard nutrition. Patients were followed for up to six months.
The study revealed similar rates of new infections in the two groups -- 53 percent who got immune-boosting nutrition had new infections, compared to 52 percent in the standard nutrition group. The type of nutrition the patients received didn't affect the amount of time spent on a ventilator, a specific measure of organ failure, or how long they stayed in the ICU. Their nutrition also did not affect the length of their overall hospital stay.
However, the six-month death rate was higher (54 percent) in the patients that received the immune-boosting nutrition than those who had standard nutrition (35 percent). Although they couldn't prove a direct cause-and-effect relationship, the researchers concluded the additional nutrients that affect the immune system were associated with an increased risk of death at six months.
In his editorial, Rice noted that many questions about immune-boosting nutrition are still unanswered, including whether any single nutrient can help certain patients. How these nutrients are given to patients (via feeding tube or IV) may also affect how they work, he added.
The U.S. National Institutes of Health provides more information on nutritional support.
Posted: August 2014