Negative impact of hypocaloric feeding and energy balance on clinical outcome in ICU patients

Background and aims: Critically ill patients with complicated evolution are frequently hypermetabolic, catabolic, and at risk of underfeeding. The study aimed at assessing the relationship between energy balance and outcome in critically ill patients. Methods: Prospective observational study conducted in consecutive patients stayingX5 days in the surgical ICU of a University hospital. Demographic data, time to feeding, route, energy delivery, and outcome were recorded. Energy balance was calculated as energy delivery minus target. Data in means7SD, linear regressions between energy balance and outcome variables. Results: Forty eight patients aged 57716 years were investigated; complete data are available in 669 days. Mechanical ventilation lasted 1178 days, ICU stay 1579 was days, and 30-days mortality was 38%. Time to feeding was 3.172.2 days. Enteral nutrition was the most frequent route with 433 days. Mean daily energy delivery was 10907930 kcal. Combining enteral and parenteral nutrition achieved highest energy delivery. Cumulated energy balance was between 12,600710,520 kcal, and correlated with complications ðPo0:001Þ, already after 1 week. Conclusion: Negative energy balances were correlated with increasing number of complications, particularly infections. Energy debt appears as a promising tool for nutritional follow-up, which should be further tested. Delaying initiation of nutritional support exposes the patients to energy deficits that cannot be compensated later on.