Enteral nutrition delivery and energy expenditure in medical intensive care patients.

BACKGROUND AND AIMS: Delivery of enteral nutrition (EN) in critical illness is often inadequate. This prospective observational study addresses the implementation of enteral feeding in critically ill medical patients and its relation to energy expenditure.

METHODS: All admissions to a university medical ICU over a period of one year were screened. Patients receiving EN for at least 7 days were followed up. The caloric target was a minimum of 20 kcal/kg/day. The feeding volume was increased daily by 500 ml and a maximum of 2000 ml/day was targeted to be achieved by day 4 of admission. Energy expenditure was measured with indirect calorimetry on day 3 or 5.

RESULTS: Two hundred and thirtyone patients required artificial nutrition, of which 61 patients were enterally fed for 7 days. This group was followed for a total of 750 feeding days. The gastric route was used at the start, with a post-pyloric feeding required during follow-up in 36.1% of patients due to high gastric residual. EN was interrupted in 32.1% of the feeding days. The daily administered volume was 86.2 +/- 30.4% of the prescribed. The mean enteral caloric supply in relation to energy expenditure was between 39.2 +/- 34.6% on day 1 and 83.1 +/- 31.1% on day 6. The targeted maximum feed volume was achieved on day 4 in 75.4% of the patients. Patients with a delayed target time had a higher mortality rate than those with a target time of <4 days (73.3% vs. 26.1%),

CONCLUSIONS: A high delivery-to-prescription rate could be achieved with a standardized enteral feeding protocol in critically ill medical patients. However, caloric delivery is much less than measured energy expenditure. Enteral feeding intolerance is associated with a high mortality rate.