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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