ENERGY REQUIREMENTS OF PEDIATRIC PATIENTS

Background and aims Malnutrition is a state in which a deficiency or imbalance of energy, proteins and other nutrients causes measurable adverse effects on functional and clinical outcomes. In particular, the nutritional status of ill children often declines after admission to the hospital and deteriorates during the course of diseases. The reported prevalence of malnutrition in pediatric hospitals ranges from 6 to 30%, however there are currently no recommendations on nutritional evaluation and risk of hospital malnutrition screening. Ill children are expected to differ in their energy expenditure when compared to healthy counterparts , to the point that growth may cease during the metabolic response to disease or injury, especially if they are in critical conditions. The most accurate method for determining resting energy expenditure is indirect calorimetry which is based on the measurement of basal metabolism from gas exchanges. However the application of this technique remains still sporadic. Alternatively, in the daily clinical practice, energy expenditure is commonly calculated by the use of predictive equations whose algorithms are based on healthy populations and are not disease-specific. The aim of this research project wasat first to assess the nutritional status of ill children admitted to a tertiary health care of northern Italy by measuring the prevalence of malnutrition and the risk of developing it during hospitalization. In the second step, we investigated energy expenditure in the course of disease in a heterogeneous population of acutely and chronically ill children to evaluate the accuracy of the WHO, Harris-Benedict and Schofield formulae in this population. Methods A prospective observational study was at first performed in five pediatric units at the IRCCS Foundation Ca’ Granda-Ospedale Maggiore Policlinico in Milan, Italy. In 245 subjects, anthropometric measurements (weight and length) were evaluated within 24 h of admission and repeated the day of discharge in order to assess wasting, stunting, and obesity according to WHO definitions. A fasting blood sample was collected to analyze nutrition-related haematochemical indexes and to test their role in predicting the length of stay. The nutritional risk was assess using the STRONGkids questionnaire. Then, a cross-sectional study including 236 infants, children and adolescents, consecutively admitted to the same five Units of this Italian Pediatric Hospital, was performed. Resting energy expenditure was measured by indirect calorimetry and estimated using the WHO, Harris-Benedict and Schofield formulae. Results The study population of the first study showed a malnutrition prevalence at admission of 10.2% wasting,and 6.5% stunting, moreover a prevalence of 7% obesity was found. Length of stay was mildly related to the STRONGkids score and was inversely associated with serum albumin. An inverse associations for serum albumin was found also with the questionnaire score. The second analysis showed a mean (standard deviation) bias between the estimated and measured resting energy expenditure of -1 (234), 82 (286), -3 (233) and -2 (214) kcal/die for the WHO, Harris-Benedict, Schofield-weight and Schofield-weight and height formulae, respectively. Conclusions To assess nutritional status, nutritional risk and appropriate biochemical indices at admission may help to predict the length of hospital stay and to optimize clinical interventions and follow-up. Furthermore, in ill children standard equations may be inaccurate and feeding strategies based on these equations might result in unintended underfeeding or overfeeding. Cumulative effects of energy imbalance can negatively impact patient outcomes and must be prevented. Accurate assessment of energy expenditure with the use of indirect calorimetry might optimize when possible energy intake during disease providing adequate feeding strategies.