[Resting energy expenditure in healthy newborn infants].

Objective: To establish the value of the resting energy expenditure (REE) in healthy newborns and evaluate relative factors of REE.

Methods: One hundred and fifty-four healthy newborns (75 boys, 79 girls; birth-weight 2,500-3,999 g) were enrolled in this study. The Apgar score at the 5th minute was equal to or more than 8; the postnatal age was equal to or more than 5 days. The newborns had no apparent defect. The mothers had no history of metabolic and endocrine diseases. REE was measured by Deltatrac II in child canopy mode for 30-45 minutes during asleep or quiet awake status.

Results: The average REE was (201.8 +/- 25.4) kJ/(kg.d), which was significantly lower than the predicted REE by Schofield formula[(226.1 +/- 4.8) kJ/(kg.d), P = 0.000], the predicted REE was 12.04% higher than the measured REE. There were no differences in sex and ways of delivery. The newborns whose birth-weight was between 2,500-2,999 g were measured in two modes: baby and child mode, and the REE values were significantly higher (122.6 +/- 25.0) kJ/(kg.d) and (208.8 +/- 26.4) kJ/(kg.d), respectively (P = 0.000).

Conclusions: The prediction formula might be improper for calculating the REE in newborn infants. The indirect calorimetry was the better way to know the actual REE of newborns. The authors recommended that in child mode the measurement of REE in newborns would be the indirect calorimetry, and the REE in healthy newborns was (201.8 +/- 25.4) kJ/(kg.d).