Transepidermal water loss in the intensive care nursery: Measuring techniques and research recommendations

Abstract

Premature newborns are at risk for high insensible water loss and low body temperatures immediately after birth because of immature skin. Evaporative water and heat losses are the result of the larger surface area in relation to body weight; increased water content, permeability, and skin blood supply; and a thinner epidermis with fewer layers of stratum corneum. Measurements of insensible water loss are performed with instruments like the Evaporimeter (ServoMed, Stockholm, Sweden), a noninvasive instrument for directly measuring transepidermal water loss (TEWL) and monitoring changes in stratum corneum barrier function. TEWL measurements in healthy adult and term newborn skin range between 5 to 10 g/m 2/h. TEWL increases if the skin barrier has been damaged by physical or chemical agents or is immature and underdeveloped. Premature infants born at less than 25 weeks ofgestation can have TEWL measurements as high as 70 g/m 2/hr. TEWL investigations in neonates are limited by the inability to control environmental factors such as incubators and radiant heaters, along with individual-related factors such as gestational age at birth, postnatal age, weight, activity, and body temperature. We present astandardized approach to TEWL measurementsin the neonatal intensive care unit for accurate and reproducible measurement of skin barrier function. Copyright © 2001 by W. B. Saunders Company