Chapter 3 ■ Maintenance of Thermal Homeostasis 25

burns, do not place oily substances on infant’s

skin. Avoid heating incubator thermometer; apply

manual temperature control (33°C to 35°C)

when using an open incubator. Keep infant

approximately 60 to 90 cm from lamp bulb, and

cover infant’s eyes and genitals to protect from the

light.

(5) Complications: Cooling or overheating of isolette due to failure to detach the thermistor from

infant; dehydration

c. Warming mattress: Extra heat source, for transport or

radiology procedures (e.g., MRI). Effective in preventing and treating hypothermia in very-low-birthweight infants (<1,500 g) in the delivery room

(2,10,24)

(1) Environment: Heating through conduction;

reduces heat requirements and IWL

(a) Heated water-filled mattress (keep at 37°C)

(b) Exothermic crystallization of sodium acetate mattress (Transwarmer Infant Transport

Mattress, Prism Technologies, San Antonio,

Texas) with a postactivation temperature of

39°C ± 1°C

(2) Access: Limited only by other equipment used

(3) Asepsis: Limited only by other equipment used

(4) Precautions: Record temperature every 10 to 20

minutes or use an infant servocontrol (ISC) continuous monitor.

(5) Complications: Hypothermia, hyperthermia,

burns

3. Mechanical devices to maintain temperature

a. Thermal resistor (thermistor): A probe placed on the

anterior abdominal wall or interscapular area. Use a

servocontrol incubator/radiant warmer to keep

infant’s temperature between 36°C and 36.5°C (4,28)

b. Convection-warmed incubator: (Fig. 3.2)

(1) Environment: Creates a microclimate for each

infant. ISC triggered by skin or air temperature;

temperature can also be set manually. Double

plastic walls, insulated mattress, and forcedheated/humidified air minimize IWL and maintain temperature.

(2) Access: Impeded by portholes, especially when

working with assistants. Improved with new

incubators/warmers to allow better access (e.g.,

Giraffe OmniBed neonatal care station [GE

Medical Systems, Waukesha, Wisconsin])

(3) Asepsis: Impossible to maintain wide sterile field

and infant position

(4) Precautions: Take infant’s temperature before

and after procedure. Use ISC and ensure that

thermistor remains in place. Add an extra heat

source (heat lamp) for unstable infants or

stressful procedures. Clinical deterioration may

require lifting the protective shield.

(5) Complications: Hyperthermia, hypothermia,

unexpected break of aseptic field

c. Radiant warmed bed: For unstable infants (28)

(1) Environment: Increases IWL by 50% in small

preterm infants.

(2) Access: Unimpeded access to infants receiving

intensive care

(3) Asepsis: Ability to maintain infant position and

wide sterile field; also allows assistants to participate

(4) Precautions: Keep infant 80 to 90 cm from radiant heat. For premature infants, heat shielding

must be added. Increase fluid infusions. Record

temperature every 5 to 10 minutes or use a continuous monitor. To avoid burns, do not place

oily substances on infant’s skin.

(5) Complications: Hyperthermia and dehydration

Fig. 3.1. Extremely low-birthweight preterm newborn wrapped

in occlusive polyethylene sheet during resuscitation.

Fig. 3.2. All aspects of homeostasis are maintained during a

procedure by use of incubator portholes, swaddling, comfortable

position, and sucrose/analgesia pacifier.

26 Section I ■ Preparation and Support

E. Special Circumstances/

Considerations

1. Regulate room temperature to one optimal for infant

(28°C to 30°C) (9).

2. Prewarm all heating units, including radiant warmers

and incubators.

3. Remember that very-low-birthweight preterm infants

and infants during the immediate newborn adaptation

period are more vulnerable to hypothermia and IWL.

This risk remains present for the first 2 to 4 weeks

according to gestational age at birth.

4. For transport outside of the NICU, use a heated, batteryoperated transport double-walled incubator.

5. Plug incubator into wall outlet during procedure to

allow battery to charge.

6. Be aware that anesthesia may inhibit the infant’s thermoregulatory capabilities.

7. Warm all anesthetic and respiratory gases to body temperature, and humidify.

8. Gastroschisis/omphalocele: These abdominal wall

defects increase the risk of heat loss, fluid imbalance,

and visceral damage. The infant may be placed in a

“bowel bag” from the torso down, or the entire abdomen may be wrapped in clean, clear plastic wrap. Avoid

visceral ischemia by keeping intestines directly above

the abdominal wall defect or keep the infant in right

lateral decubitus position (29).

9. Neural tube defects: Keep the infant in the prone position, cover the lesion with sterile gauze (soaked in

warmed sterile saline), and then wrap the trunk circumferentially with a dry gauze. Finally, cover the dry gauze

with plastic wrap to minimize insensible water losses

and prevent hypothermia (30).

References

1. Stedman’s Medical Dictionary. 27th ed. Baltimore: Lippincott

Williams & Wilkins; 2000.

2. Bissinger RL, Annibale DJ. Thermoregulation in very low-birthweight infants during the golden hour. Adv Neonatal Care.

2010;10:230.

3. LeBlanc M. Relative efficacy of an incubator and an open warmer

in producing thermoneutrality for the small premature infant.

Pediatrics. 1982;69:439.

4. Knobel R, Holditch-Davis D. Thermoregulation and heat loss

prevention after birth and during neonatal intensive-care unit stabilization of extremely low-birthweight infants. J Obstet Gynecol

Neonatal Nurs. 2007;36:280.

5. Silverman WA, Sinclair JC. Temperature regulation in the newborn infant. N Engl J Med. 1966;274:146.

6. Brück K. Temperature regulation in newborn infant. Biol

Neonate. 1961;3:65.

7. Ellis J. Neonatal hypothermia. J Neonatal Nurs. 2005;11:76.

8. Lyon AJ, Pikaar ME, Badger P, et al. Temperature control in very

low birthweight infants during first five days of life. Arch Dis Child

Fetal Neonatal Ed. 1997;76(1):F47.

9. Department of Reproductive Health and Research (RHR), World

Health Organization. Thermal Protection of the Newborn: A