Measured energy expenditure in pediatric intensive care patients
S. J. Tilden, S. Watkins, T. K. Tong and M. Jeevanandam
Pediatric Intensive Care Unit, Children's Health Center, Phoenix, Ariz.
Few data are available on energy requirements of mechanically ventilated,
critically ill children. We measured the resting energy expenditure in 18
mechanically ventilated patients between ages 2 and 18 years, using
indirect calorimetry. All patients had fractional inspired oxygen
concentration less than 0.6, no spontaneous respirations, hemodynamic
stability, and no fever or active infection, and were receiving 5%
dextrose. All subjects were hypermetabolic, since the measured resting
energy expenditure divided by the predicted basal energy expenditure from
the Harris-Benedict equations was 1.48 +/- 0.09 (mean +/- SEM). The energy
requirements calculated using "injury factors" and "activity factors"
adapted for adults is 1.62 times basal energy expenditure. The injury
factor for the pediatric multiple trauma patients should be 1.25 compared
with 1.35 in adults. In these pediatric intensive care patients 33% +/- 8%
of the energy is derived from carbohydrates, 53% +/- 8% from fat, and 14%
+/- 2% from protein oxidation. In individual critically ill pediatric
patients, energy requirements should be estimated by measuring their
resting energy expenditure whenever possible and adding 5% for their
activity. In the absence of the actual measurement of resting energy
expenditure, the recommended energy requirement is 1.5 times basal energy
expenditure. In this acute phase of injury, the daily nitrogen requirement
is 250 mg per kilogram of body weight.
