Abstracts Health Sciences

Metabolic, endocrine and nutritional aspects of critically ill children

by K.F.M. Joosten (Koen)

abstractPart 1 provides the aims of the studies (chapter 1) and a general overview and discussion of the current literature of metabolic, endocrine and nutritional aspects in critically ill children (chapter 2). In Part 2 the clinical use of an indirect calorimeter is tested and validated for use in critically ill mechanically ventilated children. In chapter 3 a new indirect calorimeter is tested in a laboratory setting using a ventilated lung model and a butane burner system to determine the accuracy of the calorimeter for use in young infants and children. The influence of low tidal volumes and low levels of oxygen consumption and carbon dioxide production with different levels of inspired oxygen concentrations is investigated. [n chapter 4 it is questioned how accurately total daily energy expenditure of mechanically ventilated pediatric patients can be estimated from measurement periods . of less than 24 hours. In addition, the influence of tube leakage on energy expenditure measurements is determined. In Part 3 the clinical use of the indirect calorimeter is tested in mechanically ventilated children. In chapter 5 using indirect calorimetry the following issues were studied: 1 What are the actual energy needs are for critically ill mechanically ventilated children? 2 What is the relation between the measured energy needs and equations predicting energy expenditure based on age and weight used for healthy children? 3 What is the relation between the ratio energy intake/measured energy and the nitrogen balance as a measure for underfeeding? In chapter 6 indirect calorimetry is used to get answer on the questions: 1 How are substrates administered with nutritional support utilized in a critically ill child? 2 Does the amount of nutritional support influences the nitrogen balance? 3 Can the difference between the measured respiratory quotient and the respiratory quotient calculated from the administered nutrients be used as a predictor of over- or underfeeding? In Part 4 the time course and variability of endocrine and metabolic parameters are studied in children with meningococcal sepsis (chapter 7). The purpose of this study is to evaluate the time course of the endocrine and metabolic responses of children during the first 48 hours of admission on the pediatric intensive care. Furthermore, we try to identify parameters that can be used to predict return to anabolic metabolism as an important prerequisite to tailor and improve nutritional support. Part 5 is the final part with discussions of the results from the previoLis studies (chapter 8). It provides recommendations for metabolic, endocrine and nutritional assessment of the critically ill child, while future perspective studies are suggested.text