Computational Model for Insensible Water Loss From the Newborn

Abstract

A mathematical model for predicting insensible water loss from the newborn infant has been developed, and its adjustable parameters have been evaluated using existing data for respiratory and transepidermal water loss components. Subsequently, the model was verified by using an independent set of available data on total insensible loss from naked infants who were not mechanically ventilated and who did not sweat. Under these conditions, the model was capable of correctly predicting the influence of ambient humidity, gestational age, and postnatal age, and in general, the predictions had a precision of +/- 14%, but they tended to underestimate insensible water loss by -16%. The straightforward algebraic form of the model makes it suitable for computerized calculations, which can be readily available at the bedside and quickly updated to account for changes in infant or environmental variables. The model is useful both for anticipating the abnormally large insensible water loss of the premature infant early in life and for computing expected changes in insensible water loss as a result of intentional manipulation of environmental factors, such as incubator temperature or supplemental humidification.