Oxygen consumption and resting energy expenditure during phototherapy in full term and preterm newborn infants

Objectives-To determine the effect of phototherapy on the oxygen consumptio n and resting energy expenditure of term and preterm newborn infants. Methods-A total of 202 infants (gestation 30-42 weeks; body weight 1270-410 0 g) requiring phototherapy for the treatment of neonatal hyperbilirubinaem ia were enrolled in a randomised crossover study. In random sequence, the o xygen consumption and resting energy expenditure were measured twice in eac h infant by indirect calorimetry, once at the end of six hours of continuou s phototherapy and once after a control period of at least six hours withou t phototherapy. Anterior abdominal wall temperature was servocontrolled at 36.5 degreesC throughout the study. Results-At the end of six hours of continuous phototherapy, oxygen consumpt ion (mean (SD): 6.21 (1.35) v 6.26 (1.51) ml/kg, p = 0.555) and resting ene rgy expenditure (178.11 (37.62) v 180.37 (43.14) kJ/kg/24 h, p = 0.382) did not differ significantly from those measured after the control period. The re were also no significant differences in heart rate, respiratory rate, or rectal temperature. Subgroup analysis of those of gestation < 37 weeks or < 34 weeks also showed no effect of phototherapy on either oxygen consumpti on or resting energy expenditure. Conclusion-Phototherapy has no effect on the metabolic rate of thermally st able term or preterm infants.