At birth, newborns are unable to regulate their own body temperature. The ability to maintain body warmth is influenced by the baby's maturity in terms of weeks of pregnancy.
A newborn's thermoregulation is a neurological system adaptation to extrauterine life. Because their neurological systems are not fully developed at birth, newborns lose body heat rapidly in four ways:
•conduction (their warm body heat transfers to cooler objects that they come into direct contact with)
•evaporation from exposure of wet skin surfaces lost to the atmosphere
•convection (their body heats transfers to the air surrounding them)
•radiation (their warm body heat transfers to cooler objects around them)
In newborns, ineffective thermoregulation is caused by immature compensation (adaptation to) the environmental temperature. In other words, when a newborn comes into contact with conduction, evaporation, convection, and/or radiation, hypothermia occurs, and they lose body heat and become hypothermic. When a newborn's body heat is lost, their immature system compensates by (this is the pathophysiology of hypothermia, or ineffective thermoregulation in newborns):
•increasing their metabolism and increasing use of glucose and oxygen (to generate more heat)
•this causes their respiratory rate to increase leading to respiratory distress
•leads to hypoglycemia
•leads to metabolic acidosis
•leads to vasoconstriction (as the body attempts to retain heat)
•increasing cold leads to the production of fatty acids that interferes with bilirubin transport and can lead to jaundice
One goal of interventions is to keep the environment temperature between 89.6*f and 92.3*f (page 206, foundations of maternal-newborn nursing, 4th edition, clinical companion, by Sharon Smith Murray and Emily Slone McKinney) so that the newborn does not develop an increased need for oxygen, an increased metabolic rate, or a normal blood sugar. This website discusses newborn hypothermia and the interventions for it (this article contains many excellent nursing interventions):
Newborn hypothermia is caused by a lack of knowledge rather than a lack of equipment." The most important factor influencing the occurrence of hypothermia is improper baby care at birth.
Many hospitals' delivery rooms are too cold, and the newborn is frequently left wet and uncovered after birth until the placenta is delivered. Soon after birth, the newborn is weighed naked and washed. Breast-feeding is frequently delayed for several hours, and the baby is kept separate from the mother in a nursery. Separation of mother and child makes it more difficult to keep the newborn warm; it also increases the risk of hospital-acquired infections and has a negative impact on breast-feeding and bonding.
Newborns who are hypothermic must be rewarmed as soon as possible. The temperature in the room where the rewarming takes place should be at least 97.6 degrees Fahrenheit. Cold clothing should be removed and replaced with pre-warmed clothing and a cap. The newborn should be quickly rewarmed; if a warming device is used, the baby should be clothed and its temperature should be checked frequently during the rewarming process. It is critical to keep feeding the baby in order to provide calories and fluid. Breastfeeding should be resumed as soon as possible. If the infant is too weak to breastfeed, breast milk can be given via nasogastric tube, spoon, or cup. It is critical to recognize that hypothermia can be a sign of infection. Every hypothermic newborn should therefore be assessed for infection.
A hypothermia diagnosis is confirmed in a hospital by measuring the actual body temperature with a low-reading thermometer, if one is available. The method of rewarming used is determined by the severity of the hypothermia as well as the availability of staff and equipment.
In cases of mild hypothermia (body temperature 36.0*-36.4*c/96.8*-97.5*f), skin-to-skin contact in a warm room (at least 25*c-77*f) can be used to rewarm the baby.
The clothed baby can be rewarmed in cases of moderate hypothermia (body temperature 32-35.9c/89.6-96.6f):
•under a radiant heater;
•in an incubator, at 35-36*c (95-96.8*f);
•by using a heated water-filled mattress;
•in a warm room: the room temperature should be 32-34°C/89.6-93.2°F (higher if the baby is small or sick);
•If the cot has been heated with a hot water bottle or a hot stone, these should be removed before the baby is placed in it.
•If nothing else is available or the baby is clinically stable, skin-to-skin contact with the mother in a warm room (at least 25°C/77°F) can be used.
•The rewarming procedure should be repeated until the baby's temperature returns to normal. Every hour, the temperature of the device being used or the room should be checked and adjusted accordingly. The baby should be fed at all times.
•Feeding should continue to provide calories and fluid, as well as to prevent a drop in blood glucose level, which is common in hypothermic infants. If this is not possible, blood glucose monitoring becomes critical, and an intravenous line should be set up to administer glucose if necessary.
•Skin-to-skin contact is the most effective way to rewarm a baby with mild hypothermia at home. The room should be warm (at least 25°C/77°F) for the best effect, and the baby should be wrapped in a warm blanket and wearing a pre-warmed cap. The rewarming process should be repeated until the baby's temperature returns to normal or the baby's feet no longer feel cold. The mother should continue to breastfeed as usual.
•Hot water bottles or hot stones can be dangerous because they can easily cause burns in babies' cold skin due to poor blood circulation. As a result, they should never be placed near the baby. If they are used to warm a cot, they should be removed before the baby is placed inside.
•If the baby becomes lethargic and refuses to suckle, this is a warning sign that he or she should be taken to the hospital. During transportation, the baby should maintain skin-to-skin contact with the mother.