Proefschrift Kerklaan

Chapter 8

according to the survey, a striking lack of consensus was identified on parenteral glucose intake and on the timing and threshold for use of (supplemental) PN (Chapter 2). The limitations of indirect calorimetry (IC) (Chapters 1 and 3), were reflected by a limited availability of IC in only 14% of PICUs. The general inadequacy of predictive equations to determine resting energy expenditure (REE) in absence of IC (Chapter 4) combined with conflicting evidence on the effect of patient- and disease-related factors on REE (Chapter 1), resulted in adoption of at least 10 different equations for energy expenditure, adjusted for a wide variety of correction factors (Chapter 2). Early initiation of enteral nutrition is preferred The most consistent finding between PICUs was the preference for enteral nutrition (EN) as route of nutrient delivery and its early initiationwithin 24 hours after admission (Chapter 2).This is in line with the general acceptance of the benefits of early EN, as shown in previous studies in critically ill adults and children 3-8 and recommendations by current guidelines for critically ill adults 9-11 . However, the beneficial physiologic effects from early provision of EN, established in many laboratory and animal models, do not automatically reflect improvement of clinical outcome. In chapter 1 it was shown that studies that claimed an improved clinical outcome with early EN in critically ill children were all observational in design. Their conclusions should be interpreted cautiously because patients who are more tolerant for EN, are usually more likely to be less severely ill. Only for critically ill children with burns, superiority of early EN has been proven by a randomised study design 12 , but recommendations for other PICU patients cannot be derived directly from this data. Despite the circumstantial evidence on the benefits of early provision of EN, there is a general consensus that EN should be initiated within 24-48 hours after PICU admission, if possible (Chapter 2) 1 . In contrast, the optimal amount of early EN remains a topic of debate. Several studies found an association between higher enteral intake in critically ill children and improved outcome 8 . This perception was reflected in the survey by the intention to meet caloric targets by the enteral route within 3 days in the majority of PICUs (Chapter 2). However, higher enteral intake is predominantly defined as a higher percentage of caloric targets achieved by the enteral route. As shown in chapter 2 and 4, caloric targets vary widely between PICUs, so an equal amount of EN provided in these PICUs might be reflected by different percentages of caloric target achieved. Careful interpretation of these data is therefore warranted. What to do with current guidelines With grade C as the maximum level of evidence, recommendations in current guidelines for nutrition support in critically ill children are based on insufficient data (Chapter 1 and 5). Many of the studies on which the guidelines are based are limited by sample size, patient heterogeneity, variability in disease severity and lack of baseline nutritional status (Chapter 5). The guidelines also do not cover every aspect of nutritional support; the A.S.P.E.N. guideline

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