Delaying Intravenous Feeding of ICU Patients May Aid Recovery
WEDNESDAY June 29, 2011 -- Temporarily withholding intravenous feedings for seriously ill patients in the intensive care unit may actually help them leave the hospital faster, new research finds.
Patients in the ICU are often too sick to feed themselves, or are on ventilators, so it's common for doctors to try feeding them through a tube directly into their stomach, and if that fails, the next step is offering nutrients intravenously, experts said. Intravenous feedings are administered into a vein.
In Europe, guidelines call for starting intravenous feedings soon after tube feeding fails, while in the United States, guidelines call for holding off about a week, as long as patients aren't already malnourished.
According to the new, multi-center trial by researchers in Belgium, the U.S. guidelines may be better.
Researchers divided 4,600 ICU patients into two groups: one received IV nutrition within two days of entering the ICU, the other had IV nutrition withheld until Day 8. (All patients received fluids to keep them hydrated.)
Death rates in the hospital and 90 days after discharge were the same in both groups. But patients who weren't fed until Day 8 on average spent one day less in the ICU, and were discharged slightly sooner from the hospital. (About 45.5 percent of people who weren't fed for a week spent more than 15 days in the hospital compared to 50.1 percent of those fed sooner.) They had fewer infections and a lower incidence of liver damage.
They were also 10 percent less likely to be on a ventilator for more than two days and less likely to need dialysis because of renal failure. They also incurred slightly lower costs, about $1,600 less per patient.
"What we found was that the recovery of the patients who did not get the [IV] feeding right away was quicker. They had less need for mechanical ventilation, dialysis due to kidney failure and fewer infections," said senior study author Dr. Greet Van den Berghe, director of the department of intensive care medicine at University of Leuven in Belgium. "Altogether, this made them leave the ICU quicker and the hospital quicker."
The study, published online June 29 by the New England Journal of Medicine, included patients of varying ages who were in the ICU for many reasons, including transplant surgeries and trauma.
The study is important because it subjected IV feeding, a routine practice in ICU, to the rigors of a large, randomized clinical trial, which was long overdue, said Dr. Thomas R. Ziegler, a professor of medicine at Emory University School of Medicine in Atlanta.
"What this tells us is that the routine use of IV nutrition very early in the ICU course provides no benefit and is associated with slightly worse outcomes than waiting a week," said Ziegler, who wrote an accompanying editorial for the journal.
But the findings should be interpreted cautiously, he added. Before the advent of IV feeding in the late 1960s, seriously ill patients who couldn't eat could literally starve to death. Even today, malnutrition among seriously ill patients remains an issue.
"It is critical to appreciate that adequate nutritional status is critical for optimal cell and organ function and recovery from illness," said Ziegler.
The patients studied showed no signs of malnourishment when they entered the ICU. For patients already experiencing that, giving IV feedings sooner may be warranted, he said.
"I would caution that these data not be over-interpreted to say nobody in the ICU should get [IV] nutrition," he added. "The differences in outcome were small, the rates of mortality were the same and a large number of the patients were not seriously malnourished to begin with."
IV feedings include proteins, sugar and fats, along with vitamins and minerals.
Researchers aren't sure why holding off on feeding may aid in patients' recovery. But they believe that eating sends a signal to the body that all is well, which may suppress a process called autophagy that clears damaged cells from the body, part of the recovery process.
Prior research has been inconclusive, with some studies showing a benefit to earlier feeding and some showing benefits from holding off, which is why the European and American guidelines differ.
"The European guidelines definitely have to change," Van den Berghe said.
Now that more is known about the timing of feeding, Ziegler said future trials should revisit the amount of calories patients receive.
The American Thoracic Society has more on what to expect in an ICU.
Posted: June 2011