MAM and TRM conceived the premise and participated in writing, interpretation and analysis. All authors have read and approved the final manuscript.AcknowledgementsThe Olaparib chemical structure authors are grateful to the nurses for their invaluable and precious help during the collection of samples in the ICU.
Nutrition is an integral and important part of therapy in the ICU. Nutritional therapy aims at conservation or restoration of the body protein mass and of provision of adequate amounts of energy. On a hypothetical basis, surrogate markers for optimal nutrition with regard to energy and protein provision have proposed to be the delivery of energy as measured by indirect calorimetry, and provision of 1.2 to 1.5 g of protein per kg of pre-admission weight for critically ill patients [1].
It has been shown that inadequate provision of energy correlates with the occurrence of complications, such as adult respiratory distress syndrome, infections, renal failure, pressure sores and need for surgery [2,3]. Recently, Anbar and colleagues [4] have provided preliminary evidence in a group of 50 patients with an expected ICU stay of more than three days, that provision of energy according to indirect calorimetry led to cumulative positive energy balances whereas the control group (targeted at 25 kcal/kg) had negative cumulative energy balances; hospital morbidity and hospital mortality decreased in the intervention group.Studies aimed at improving nutritional support by implementing evidence-based algorithms have failed to demonstrate significant positive effects on survival, but the nutritional goals as proposed for the surrogate markers for optimal nutrition were not achieved [5-7].
The lack of findings of clinically relevant effects of nutritional therapy in earlier studies might thus be explained by not attaining adequate provision of energy and protein.In the present study we analyze the effects of reaching energy provision guided by indirect calorimetry and provision of at least 1.2 g/kg pre-admission body weight. We sought for an effect of optimal nutrition on mortality as outcome parameter.Materials and methodsThe study was prospectively undertaken in a group of mixed medical-surgical patients in a tertiary university hospital.
According to the American Association for Respiratory Care (AARC) guidelines [8], we selected patients who require long-term acute care, patients with a known or suspected nutritional deficit, and subgroups with Brefeldin_A a nutritional and stress factors that may considerably skew prediction by Harris-Benedict equation. The long-term acute care patients were included if on days three to five (timing of indirect calorimetry) the foreseeable period of artificial nutrition was another five to seven days at least; if age was over 18 years and if it was a first admission to the ICU during the hospital stay. Limiting factors for inclusion were: fraction of inspired oxygen of more than 0.