Prediction of the Basal Metabolism of Infants from the Measured Insensible Perspiration.

Abstract

Measurement of the respiratory exchange of infants by present methods is time-consuming and technically difficult. The result is that only 3 or 4 pediatric clinics in America are making any attempt at present to study the subject. This paucity of data is regrettable since a knowledge of the energy metabolism furnishes the scientific basis for the feeding of infants in health and in nutritional disturbances, besides yielding valuable information in many other conditions. For these reasons, the attempt has been made to extend to infants the method proposed by Benedict and Root 1 for predicting the probable metabolism of adults from the insensible perspiration as measured with the aid of a delicate balance. The results thus far obtained with the method are presented in this preliminary report.

The method is based on the close relationship which exists in the human organism from early infancy to old age between the production of heat and the loss of heat by way of vaporization of water through the skin and lungs. Du Bois 2 has shown that under standard conditions of clothing, temperature and humidity, healthy adults at rest and in the post-absorptive state lose approximately 25% of their heat in vaporization through the above channels. This relation was maintained in all of the afebrile diseases investigated.

Simultaneous measurements of heat production and water elimination in the respiration chamber at the New York Nursery and Child's Hospital demonstrated that under comparable conditions normal and marasmic infants lose the same proportion of heat in vaporization as adults; namely, 26%, the extreme values being 23 and 30%. 3 The chart shows this relation between heat production, expressed as calories per 24 hours, and insensible perspiration, expressed as gm. per hour.