Proefschrift Kerklaan

Use of indirect calorimetry to detect overfeeding

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Figure 1. Correlation between RQ-RQ macr

and caloric intake/mREE (r=0.627, p<0.001). Dotted line

represents the generally applied cut-off value for overfeeding RQ = Respiratory Quotient, mREE = measured Resting Energy Expenditure

DISCUSSION

This study showed that when different definitions indicating overfeeding were applied to a group of critically ill mechanically ventilated children, a wide variation in the proportion of children identified as overfed was found, ranging from 23% to 50%. RQ exceeded RQ macr +0.05 from a ratio caloric intake/mREE of 165%. Overfeeding in critically ill children has been predominantly reported with the definition based on the ratio caloric intake/REE (Table 1) 14,21-25,27,28 . The proposed and frequently used upper limits of 110% or 120% are, however, consensus based and not derived from sound studies with clinical endpoints. A recent systematic review in which 9 studies were summarized and a recent single-center study by Jotterand Chaparro et al., investigated the influence of energy and protein intake on protein balance in critically ill children. It was found that a minimum intake of respectively 57 and 58 kcal/kg/day and of 1.5 g protein/kg/day were required to achieve a positive protein balance 19,20 . Taking into account a ratio caloric intake/ mREE >110% and >120%, a subgroup analysis of our study showed that 36% and 23% of the children, respectively, did not achieve this minimal energy intake of 57 kcal/kg/day but would be identified as being overfed. This identification of a patient as being overfed while they can be presumed to have a negative protein balance would be a contradiction, regardless of the

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