Thermoregulation: Advances in Preterm Infants

Abstract

* Abbreviations: NTE: : neutral thermal environment T3: : thyroxine T4: : triiodothyronine 1. Thermoregulation of preterm infants is often overlooked, precipitating hypothermia. 2. Clinicians should understand the morbidities and the mortality associated with hypothermia in preterm infants. 3. Clinicians should be able to plan appropriate management to prevent hypothermia after birth and beyond. After completing this article, readers should be able to: 1. Describe the mechanisms of heat production and heat loss in neonates, and why preterm infants are more susceptible. 2. Identify the conditions leading to hypothermia in preterm infants and its consequences. 3. Recognize the different ways of preventing hypothermia in preterm neonates. Newborns must undergo many adaptations after delivery to adjust to extrauterine life. One of the paramount adjustments is the need to rapidly increase body temperature, and strive to accommodate to an environment colder than that of the prenatal milieu. The temperature of a fetus is 0.9°F (0.5°C) above the maternal temperature but within a few minutes after birth, the neonatal core temperature begins to fall. (1) Keeping newborns warm, especially preterm infants, can be challenging. Preterm infants can be characterized as inefficient homeotherms. Although they do have an initial appropriate response to a decrease in environmental temperatures, the effect is limited, placing the preterm infant at high risk for hypothermia with all of its associated complications. Budin (2) and Silverman, pioneers in the field of neonatology, had observed significant mortality among low-birthweight infants who were hypothermic on admission to the nursery and in the first few days after birth. (3) They noted a striking improvement in survival rates if infants were cared for in warm environments, especially in the first 5 days after birth. Budin found a significant difference in mortality based on the temperature of newborns at the time of admission to the NICU. In this study, the mortality rate in neonates weighing less than 2,000 g was as high as 98% …