|Energy-dense enteral feeding fails to improve survival in ICU patients|
|Daily-needed energy is usually delivered to intensive care unit (ICU) patients with a low density by the enteral route. Currently, liquid formulas with a density of 1 kcal/ml are commonly applied to patients with a rate of 1 ml/kg body weight/hour in practice. Due to many conditions during feeding, approximately less than 60% of designated volume can be delivered to patients, suggesting potentially unfavourable outcomes resulting from unmet energy requirement. However, controversy arguments exit regarding increased energy intake in ICU patients—some suggest increased energy delivery improves outcomes; some suggest short-term underfeeding does not associate with adverse effects; some suggest increased delivery is harmful.
A team composed with ICU doctors from Australia and New Zealand performed and published this study (The Augmented versus Routine Approach to Giving Energy Trial, TARGET) in a recent issue of the New England Journal of Medicine (here), in order to test whether delivery of high-density energy in ICU patients could improve survival of ICU patients during the first 90 days. This multiple-centre randomized study recruited 3957 ICU patients treated with invasive mechanical ventilation—1971 patients receiving an increased energy formula of 1.5 kcal/ml (the 1.5-kcal group) and 1986 patients receiving a routine energy formula of 1.0 kcal/ml (the 1.0-kcal group). All patients were fed with a targeted rate of 1 ml/kg ideal body weight/day enterally in an early time point after ICU admission (the ideal body weight rather than the actual body weight was used in order to avoid overfeeding), which lasted for up to 28 days. The primary endpoint of this study was the survival during the first 90 days.
Patients in both groups obtained similar volumes of nutrition (1242±318 ml in the 1.5-kcal group, and 1262±313 ml in the 1.0-kcal group), but individuals in the 1.5-kcal group received increased levels of energy than those in the 1.0-kcal group (1863±478 kcal per day v.s. 1262±313 kcal per day). During the first 90 days after ICU admission, 523 patients in the 1.5-kcal group died (26.8%), compared to 505 cases in the 1.0-kcal group (25,7%), indicating no difference in all-cause death within 90 days between two groups. Moreover, energy-dense supplement did not affect other prognostic parameters between the two groups, including ICU and hospital stay, although patients in the 1.5-kcal group harbored higher rates for upper gastrointestinal intolerance and hyperglycemia.
This study indicates that high-energy delivery by the enteral route in critically ill patients that are supported by mechanical ventilation does not improve the survival within 90 days after ICU admission nor other outcomes. However, whether this result applies to surgical patients, especially patients undergoing major upper abdominal surgical procedures, requires further investigations.
This trial was supported by a pharmaceutical company.