Background Artificial nutrition is an essential component in the management of critically ill patients. These patients are at risk of developing malnutrition, which occurs in up to 40% of patients and is associated with increased mortality and morbidity.

Purpose To evaluate the difference between the estimated energy requirements in those that were prescribed and those who actually received artificial nutrition, for patients admitted to an intensive care unit (ICU), and to identify the reasons for the discrepancies.

Material and methods The study was conducted in a 12 bed ICU of a referral hospital, from May to July 2015. Patients with nutritional support (NS) and ICU stay >7 days were selected. Demographic and clinical data were collected, and energy requirements were calculated using the Harris-Benedict equation adjusted by the stress factor. For NS, the following data were collected during the first week of ICU admission: start date, type of nutrition, kilocalories prescribed and administered, and grams of protein prescribed and administered. Also taken into account were the calories provided by propofol if prescribed.

Results 27 patients were included, with a mean age of 62.8 ± 17.5 years.71.4% were men. 42.8% were prescribed enteral nutrition and 57.2% parenteral nutrition. The average delay in the start of the NS was 3.1 ± 1.3 days. The average estimated kilocalories per kilogram (kcal/kg) was 25.5, with 16.6 kcal/kg prescribed and 14.6 kcal/kg actually administered (60% of the theoretically estimated requirements), resulting in a calorie deficit accumulated over 7 days of – 4763 ± 2739 kcal. For proteins, the requirement was 1.4 g/kg, with 0.7 g/kg prescribed and 0.6 g/kg administered (40% of the theoretically estimated requirements), with an average protein accumulated deficit of – 297 ± 167 g. This was due to the following factors: tolerance of enteral feeding, delayed prescription (in 11% of patients nutritional support began on day 5), prescription below estimated requirements and pauses in administration due to intra/extra procedures in the ICU.

Conclusion The amount of calories that patients received was low, being more pronounced for administered proteins. With these results, measures directed to optimising nutritional support of our patients are needed.

No conflict of interest.