Abstract
INTRODUCTION: Critically ill infants and children who require mechanical ventilation are susceptible to malnutrition. Formulas for determining energy requirements in these patients have not been accurate and reliable. Knowledge of their energy requirements is essential for designing nutritional regimens to reduce carbon dioxide production. Inappropriate nutritional support may add to the effects of disease and prolong recovery and mechanical ventilation. OBJECTIVE: We attempted to derive new equations for estimation of measured energy expenditures (MEE) in children and infants receiving mechanical ventilation in the pediatric intensive care unit (PICU). METHODS: We retrospectively compared the values of MEE to those predicted by the Harris-Benedict (HB), the World Health Organization (WHO), and the Schofield equations, for all PICU patients evaluated with a metabolic cart from 1/1/92 to 3/31/95. Indirect calorimetry was performed on mechanically ventilated patients receiving oxygen concentrations ≤ 0.60 and with no audible air leak. RESULTS: 60 children (34 boys; 26 girls) with a mean (SD) age of 7 (6.8) years were identified, and 77 measurements were performed. MEE was significantly less than energy expenditure estimated by HB or WHO equations. The Schofield equation significantly underestimated MEE. Equations resulting from multiple linear regression analysis of MEE were: Boys: MEE (Kcal/day) = 3.3 Height (cm) + 5.7 Weight (kg) + 75.7 Age (years) + 42.3 (r2 = 0.78); girls: MEE (Kcal/day) = 13.9 Height (cm) + 9.5 Weight (kg) – 42.2 Age (years) - 507 (r2 = 0.85). CONCLUSION: Accurate, direct measurements of energy expenditure are recommended, but when a metabolic cart is not available, the equations derived from our data should provide a good estimation. [Respir Care 1996;41(3):191-196]
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