Thermal equilibrium as a predictor of growth efficiency in preterm infants

Abstract

Introduction: Providing adequate nutrition to preterm infants to achieve postnatal growth similar to intrauterine growth remains challenging due to the unpredictability of individual determinants.

Material and methods: We used a calculation program for infant incubators to compare the estimated heat balance with the caloric intake and growth rate in Very Low Birth Weight Infants (VLBWI).

Results and discussion: A group of 32 VLBWI was studied over a period of 14-28 days. An interrelationship between thermal equilibrium and growth rate was observed, with standardized incubator settings being unable to avoid periods of negative thermal balance and concomitantly poor growth rate.

Conclusion: Determining personalized incubator settings by means of a calculation program could help improve nutrition and growth in preterm infants.

Keywords: calculation program; caloric intake; growth rate; heat exchange; incubator settings; preterm infants.

Figure 1

Screen view example of the HeatBalance® program. Heat production, heat losses, and heat balance are displayed after entry of patient and incubator data.

Figure 2

Percentage body weight (a), nutritional caloric intake and estimated heat production (b), specific growth rate (c), and net heat balance (d) in 32 VLBWI. Growth sets in as soon as an energy excess (caloric intake minus heat production) of around 50 kcal/kg/d is achieved/exceeded. Overall, the specific growth rate parallels the net heat balance, with a negative heat balance being accompanied by a temporary retardation in growth rate.