Proefschrift Kerklaan

Summary

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.

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