Respiratory contribution to the thermal balance of the newborn infant under various ambient conditions
Sulyok, E.; Jéquier, E.; Prod'hom, L.S.
Pediatrics 51(4): 641-650
1973
ISSN/ISBN: 0031-4005 PMID: 4697513 Document Number: 64723
Forty-five newborn, term, healthy infants, Apgar score 8 or more, were studied within 24 h after birth. The gradient layer calorimeter used is described with the techniques and the assumptions made. Table 1 reports the clinical characteristics of the infants in 5 groups, subjected to different combinations of temperature and relative humidity (r.h.): 28 deg , 32 deg and 36 deg C at 50% r.h. and 20, 50 and 80% r.h. at 32 deg C.At 32 deg heat production was least at 50% r.h. At 28 deg heat production rose by a significant amount and at 36 deg heat production fell. At 28 deg with loss of storage heat there was a substantial loss of dry heat and at 36 deg , with increased heat storage, there was less loss of dry heat. Evaporative heat loss at 50% r.h. was least at 32 deg and was then 18.35% of total heat production. At 28 deg and 36 deg evaporative heat loss was 15.14 and 25.42% of total production. Respiratory heat loss was least at 32 deg and 50% r.h. when it was 33.56% of total evaporative heat loss. At higher temperature it rose more rapidly than evaporative loss from the skin. It is thought that such data should contribute to more rational planning of the infant's environment.