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Summary
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The main findings of this thesis are summarised in Table 1.
Chapter 1
Nutritional support affects recovery and outcome in critically ill children, but its application
is supported by a scarcity of high-level evidence. For that reason, the optimal timing, amount
and route of nutrition in the Paediatric Intensive Care Unit (PICU) remain debatable. This results
in a wide variation in clinical practice, which impacts outcome of critically ill children.
In the introduction of this thesis an overview is provided of the different aspects of nutritional
support in critically ill children in relation to the different phases of the stress response. The
characteristics of the different phases of critical illness are described, followed by an elaboration
on the optimal nutrition strategy for each phase.
Finally, an overview is given on the use of energy expenditure to guide nutritional therapy
throughout the course of critical illness. Chapter 1 ends with the aims and outline of this thesis.
Chapter 2
International consensus-based guidelines on nutritional support in critically ill children
generally rely on expert opinions and studies in adults or non-critically ill children, and
provide rather non-specific recommendations. To identify local strategies and guidelines,
we distributed a two-part online survey to PICUs across the world. In addition we compared
the local guidelines with nutritional data collected in all patients present on a single day in a
subgroup of the responding PICUs. We observed that, due to the limited guidelines, current
nutritional practices vary widely between PICUs worldwide. Most variation was observed in
macronutrient targets, the estimation of energy requirements and the threshold for the use
of (supplemental) parenteral nutrition (PN). Subsequently, we found that applied nutritional
practice deviated from local protocols or strategies onmultiple occasions.The onlywide-spread
consensus appeared to be on the preference for the enteral route and its early initiation. These
results highlight the need for sound clinical studies to develop evidence-based guidelines on
nutritional support for critical ill children, since inconclusive and low-level evidence appears to
represent a barrier to clinical implementation.
Chapter 3
Measurement of resting energy expenditure (REE) through indirect calorimetry (IC) is the
preferred method to determine energy requirements in critically ill children. Since availability
of IC is limited worldwide, most PICUs rely on predictive equations to determine REE. However,
these equations cannot accurately predict REE in critical illness, because they are derived
from measurements in healthy children. Fortunately, VCO
2
values to calculate REE can also be
automatically subtracted from a ventilator.