In the moments after birth, it is important for all newborn babies to maintain an optimal body temperature. When it comes to premature infants, achieving newborn thermoregulation can be a challenge due to their underdeveloped skin, underdeveloped ability to sweat or shiver, large surface-to-body mass ratio, and higher metabolic rate.
As a NICU nurse, you need to help the infants in your care balance heat production and loss to maintain a normal body temperature, which is between 36.5°C and 37.5°C (97.7°F and 99.5°F), according to the World Health Organization.1
Infants can lose heat in multiple ways: through insensible water loss from their skin and respiratory tract, when they are transferred to cool surfaces, through cool air from open incubator ports, or as heat naturally radiates from their bodies. Following birth, heat loss can occur quickly in newborns—between 0.1°C and 0.3°C per minute. One must also consider factors particular to each infant—such as their weight, gestational age, and health status—creating a unique and dynamic thermoregulatory care challenge for any NICU nurse.
With awareness and consideration of risk factors (bed, baby, building, bedside caregiving), environmental changes, and available technologies, here are a few tips to ensure your delicate patients stay at an ideal temperature.
1. Recognize Signs of Abnormal Temperature
If an infant cannot maintain a steady, normal temperature, there are potential impacts on their health and development. If too warm—or hyperthermic—newborns are more likely to appear flushed or show signs of fast breathing rates or fast heart rates. If the temperature remains elevated for a long time, then the infant is at risk for dehydration or insensible water loss, resulting in electrolyte imbalances.
If too cold—or hypothermic—newborns may consume more oxygen and glucose to produce heat, which may lead to hypoxia or hypoglycemia. Hypothermia can also alter the natural patterns of blood flow, increasing risks for intraventricular hemorrhage and necrotizing enterocolitis. These are serious concerns given that low admission temperature or the development of hypothermia after admission increases an infant's risk of death and infection.
Temperature abnormalities can be subtle, but with close attention, you can spot presenting symptoms and intervene in time. Signs to note include the following:
- A hypothermic infant may breathe shallowly (with potential periods of apnea or bradycardia), appear lethargic and hypotonic, and feed poorly with a weak suck. They may have pale, mottled skin, and decreased capillary refill time.
- A hyperthermic infant may be breathing faster, have an increased heart rate (tachycardia), appear restless or irritable, and cry weakly. Their skin may be redder and flushed.
2. Consider Special Circumstances
Certain conditions can elevate the risk of problems with newborn thermoregulation. Infants with the following complications require increased frequency of temperature monitoring and possible intervention.
- Preterm infants: Infants born before 37 weeks gestation have more difficulty maintaining their body temperature. Their skin is more permeable with higher heat loss, they are neurodevelopmentally immature, and they have less insulating brown fat (which starts developing at 26 weeks gestation).
- Low birth weight or intrauterine growth-restricted infants: These smaller-than-average babies will have less subcutaneous fat, decreased glycogen stores, poorer vascular control, and a slower metabolism.
- Infants prone to hypoglycemia and hypotonia: Infants with these conditions—such as those with Down syndrome or born to diabetic mothers—will have altered metabolism levels and difficulty using muscle control for thermoregulation.
- Congenital problems: Infants born with issues such as gastroschisis, exomphalos, ichthyosis, or epidermolysis bullosa carry the risk of evaporative heat loss due to exposure of the defect or skin integrity disruption.
- Infection: Infants at higher risk of sepsis, such as in situations of maternal group B streptococcal infection, maternal chorioamnionitis, or prolonged rupture of membranes, must be monitored closely for temperature alterations.
3. Mind Temperature During Care Transitions
Changes in the environment can easily alter a newborn's temperature. Paying close attention to environmental transitions will minimize the thermoregulation challenges of the infant. A study in the Journal of Obstetric, Gynecologic and Neonatal Nursing found unintentional exposures can occur when patients are being transported, undergoing procedures, laying on cool X-ray plates or scales, or during breastfeeding.2
Nurses can mitigate these exposures through the following methods:
- Ensure that any surfaces the infant will touch are pre-warmed.
- When bathing, make sure the water temperature is appropriate and keep the bath as short as possible.
- Consider the frequency and duration of open incubator portholes, supporting the temperature with an air curtain.
- When wrapping or dressing the infant, include a hat, as the head is a large surface for heat loss.
- If infants are stable enough to breastfeed, place the infants in a chest-to-chest position with a single blanket. When appropriate, incorporate kangaroo mother care into the infant's daily routine.
4. Know Your Thermoregulation Equipment
Technology exists to help manage the optimal thermal environment for infants, including solutions such as radiant warmers and incubators with skin temperature monitoring devices. Closed bed incubators additionally have humidification to support thermoregulation due to water loss from the skin. When using these technologies, be certain you are familiar with their features and operations (and common troubleshooting issues, just in case.)
As you use the technology in your unit, keep the following in mind:
- Reliable neonatal temperature monitoring is vital. Consider how temperatures measured from the abdomen, axilla, or extremities may be affected by environmental factors, such as contact with a heated bed, probe placement, or the infant's position.
- Always check radiant warmer and incubator settings prior to infant use and monitor them frequently. Ensure the thermal set point is appropriate for the infant's weight and gestational age.
- Consider technology that can minimize exposure and transitions and support developmental care, such as radiant warmers that convert to incubators once infants have been stabilized, as well as those with platform rotation features that allow for proper positioning for procedures or care without the need to physically move the infant.
- Don't forget the supplemental aids to support thermoregulation, such as polyethylene bags at delivery, consistent use of hats and wraps, as well as skin-to-skin contact and kangaroo mother care. Combining both the simple and more complex thermal devices and aids can help you create an effective, individualized bundle of thermoregulatory care.
Above all, remember to continually refresh your training and build upon your team's experiences. Use teamwork and quality improvements in your unit to help everyone get better at achieving excellent thermoregulatory care. By helping these infants maintain an optimal temperature, you are helping their health radiate from within.
References:
- Maternal Health and Safe Motherhood Programme. Thermal control of the newborn: a practical guide. World Health Organization. https://apps.who.int/iris/bitstream/handle/10665/60042/WHO_FHE_MSM_93.2.pdf
- Knobel R, Holditch‐Davis D. Thermoregulation and heat loss prevention after birth and during neonatal intensive‐care unit stabilization of extremely low‐birthweight infants. Journal of Obstetric, Gynecologic & Neonatal Nursing. 2007;36(3):280-287. doi:10.1111/j.1552-6909.2007.00149.x
