Delaying parenteral nutrition speeds recovery of critically ill patients
MedWire News: Patients admitted to the intensive care unit (ICU) make a faster recovery if parenteral nutrition is delayed until 8 days after admission, as opposed to being started within 48 hours, shows a randomized trial.
However, mortality was not affected by the timing of parenteral nutrition, report Greet Van den Berghe (University Hospital Leuven, Belgium) and colleagues.
The findings, published in the New England Journal of Medicine, lend support to the 2009 guidelines from the Society of Critical Care Medicine and American Society for Parenteral and Enteral Nutrition, rather than those published by the European Society for Clinical Nutrition and Metabolism.
All 4640 patients in the study received intravenous dextrose from the first day of admission to the ICU, and enteral nutrition from day 2. The patients were randomly assigned to receive supplemental parenteral nutrition from day 2, to achieve full nutrition, or to receive intravenous vitamins, minerals, and trace elements, with parenteral nutrition withheld until day 8.
The primary outcome was duration of ICU stay. The median was 3 days in the late-initiation group, which was significantly shorter than the 4-day median in the early-initiation group. The difference equated to a significant 6.3% increased likelihood of being discharged earlier if parenteral nutrition was delayed.
Mortality was similar in the two groups, with 6.1% and 6.3% of patients in the late- and early- initiation groups, respectively, dying in the ICU, 10.4% and 10.9%, respectively, dying in hospital, and 11.2% of both groups dying within 90 days of enrollment.
Infection was less common in the early- than late-initiation groups, at 22.8% versus 26.2%, and fewer patients required ventilation for longer than 2 days, at 36.3% versus 40.2%.
Conversely, hypoglycemia was more common if parenteral nutrition was initiated late, at 3.5% compared with 1.9% in the early-initiation group. Also, inflammation was more marked, with median peak C-reactive protein levels of 190.6 and 159.7 mg/l, respectively.
Finally, withholding parenteral nutrition was associated with a reduction in total hospital costs, of about US $1600 (€1122) per patient.
In an accompanying editorial, Thomas Ziegler (Emory University School of Medicine, Atlanta, Georgia, USA) cautioned: "These data should not be overinterpreted, since between-group differences in outcome were small, rates of death in the two groups were similar, approximately 80% of the patients were not seriously malnourished at entry… and 60% were admitted to the ICU after cardiac surgery,"
He also noted that the daily intravenous vitamins and trace elements given to patients in the late-initiation group could have influenced the findings.
Although the actual requirements of ICU patients are unknown, Zielger said that "it may be prudent to provide complete enteral or parenteral preparations of vitamins and trace elements if parenteral nutrition is delayed in patients who cannot tolerate full enteral nutrition."
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By Eleanor McDermid