1995 OPEN FORUM Abstracts
ESTIMATION OF ENERGY EXPENDITURE IN CRITICALLY ILL INFANTS AND CHILDREN RECEIVING MECHANICAL VENTILATION IN THE PEDIATRIC INTENSIVE CARE UNIT.
Mohamad F. El-Khatib. Div. Pharmacology & Critical Care, Bonnie Rosolowski, RRT, Department of Pediatric Respiratory Care, Rainbow Babies & Children's Hospital, Cleveland, OH.
INTRODUCTION: Critically ill infants and children requiring mechanical ventilation are particularly susceptible to malnutrition. A knowledge of the energy requirements of these patients is essential in designing nutritional regimens to reduce CO2 production during mechanical ventilation. Lack of appropriate nutritional support in these patients may add to the effects of disease and prolong recovery and mechanical ventilation. OBJECTIVE: In this study we assessed the reliability of the Harris-Benedict (HB) equation (a widely used equation for estimating energy expenditures) in estimating energy requirements in children and infants in the Pediatric Intensive Care Unit (PICU). METHOD: We retrospectively compared the values of measured energy expenditures (MEE) to those predicted by the HB equation (PEE) for all PICU patients who were evaluated with a metabolic cart from 1/1/1992 to 3/31/1995. Indirect calorimetry (IC) was performed on patients receiving mechanical ventilation with FiO2ឬ% and with no audible airway airleaks. each patient was evaluated for at least 15-20 minutes and data for analysis were obtained from 5-15 minutes steady-state periods.
Results: 60 children (34 males; 26 females) with a mean age of 7 years (range: 1month-18 years) were identified and included in the study. A total of 77 IC measurements were performed (44 for males and 33 for females). Primary underlying diseases were respiratory (23 patients), cardiac (17 patients), neurologic (6 patients), and others (14 patients). MEE was significantly less than PEE (47.9±19 vs. 60.4±38 Kcal/kg/day, p < 0.01). Multiple linear regression analysis performed on MEE resulted in the following equations:
MEE(Kcal/day) = 3.3 Height(cm) + 5.7 Weight(kg) + 75.7 Age(years) + 42.3 r^²=0.78
MEE(Kcal/day) = 13.9 Height(cm) +9.5 Weight(kg) - 42.2 Age(years) - 507 r^²=0.85
CONCLUSION: Accurate and direct measurements of energy expenditure is recommended in critically ill infants and children receiving mechanical ventilation in the PICU. In the case of an unavailable metabolic cart, the above derived equations should provide a better estimation of energy requirements than the Harris-Benedict equation.