Proefschrift Kerklaan

Use of indirect calorimetry to detect overfeeding

this specific group of children. This hypometabolic state was reflected in an increased ratio caloric intake/mREE of 145% 43 . We also found that children identified as being overfed by the ratio caloric intake/mREE, had a significantly lower SD-score, compared to children without overfeeding. This contrasting combination of loweredmREE and caloric overfeeding described in malnourished children, might be linked to an amplification of mitochondrial dysfunction associated with the stress response 43,44 . Therefore the effect of nutritional status on the risk of overfeeding may be intertwined with the phases of critical illness. reflects the use of different macronutrients within a patient, it acts as a more functional parameter to describe overfeeding throughout the course of illness and for different age groups. The use of this parameter might be, however, limited when caloric intake is less than mREE 45 and during the acute phase of critical illness when endogenous energy production is present, even with adequate energy provision 46 . RQ is also affected by factors unrelated to feeding 29 . Our study is further limited by the small number of patients, the lack of clinical endpoints, and the fact that we only performed single measurements. Therefore, it should be followed by larger prospective studies on the effect of intake on clinical outcomes, preferably with a longitudinal design. To conclude, the proportion of mechanically ventilated patients identified as overfed ranged widely from 23% to 50% depending on the criteria applied. The currently used definitions to describe overfeeding fail to take into account several relevant factors associated with critical ill children and are therefore not generally applicable to the PICU population. We advocate the development of a definition for overfeeding dependent on age, nutritional status and phase of illness, preferably based on clinical outcome measures. Because the difference of RQ-RQ macr

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