What does the research evidence show regarding thermoregulation and optimal temperature management in premature infants?

Thermoregulation in Premature Infants: Evidence-Based Management

Maintain premature infant temperature between 36.5-37.5°C using a combination of interventions including polyethylene wrapping, thermal mattresses, and servo-controlled incubators, with continuous temperature monitoring to prevent both hypothermia and hyperthermia. 1, 2

Target Temperature Range

• The World Health Organization recommends maintaining newly born infant temperature between 36.5-37.5°C after birth 1
• This target of 37.0°C is essential for all newborns, with particular emphasis on continuous monitoring in premature infants 2
• Abnormal temperature (both hypothermia and hyperthermia) is independently associated with increased morbidity and mortality in preterm infants 1

Delivery Room Management

For infants <32 weeks gestation, immediately apply both a polyethylene bag and skullcap in the delivery room. 2

• The International Liaison Committee on Resuscitation (ILCOR) recommends using a combination of interventions to prevent heat loss in very preterm infants 1
• Despite current guidelines, abnormal temperature remains prevalent across all climates and economies, with recent efforts to prevent hypothermia inadvertently increasing hyperthermia incidence 1

Skin-to-Skin Contact Considerations

• Skin-to-skin contact is the easiest and most rapidly implementable method to prevent body heat loss 2
• However, immediate skin-to-skin contact in preterm infants shows a slight decrease in temperature after 60 minutes, though this does not significantly impact clinical outcomes including hypothermia rates, hypoglycemia, or respiratory support needs 3
• The evidence remains uncertain regarding optimal timing and implementation of skin-to-skin contact in the context of emerging practices like delayed cord clamping 1

Ongoing Thermal Management

Equipment Selection

For preterm infants weighing <1600g, use a closed, convective incubator with humidified and warmed inhaled gases. 2

• There is no clear benefit for single-wall versus double-wall incubators 2
• Air versus skin servo control shows no definitive advantage 2
• Servo-controlled devices (radiant warmers, incubators, thermal mattresses) are recommended but have not been definitively proven to improve rewarming outcomes 4

Monitoring Protocol

• Frequent or continuous temperature monitoring is essential, particularly when using supraphysiological set temperature points to accelerate rewarming 4
• More frequent axillary temperature monitoring helps prevent both hypothermia and hyperthermia 5
• Monitor blood glucose in any hypothermic infant due to increased hypoglycemia risk 4

Rewarming Hypothermic Infants

When rewarming unintentionally hypothermic newborns, use a standardized protocol with continuous temperature monitoring, but there is insufficient evidence to recommend either rapid (≥0.5°C/hour) or slow (<0.5°C/hour) rewarming rates. 4

Critical Rewarming Considerations

• A safe maximum rate of rewarming has not been identified 4
• The included studies were too small to determine the effect of rewarming rate on mortality and other critical outcomes 4
• Rapid rewarming showed association with reduced respiratory distress syndrome in one observational study, but clinical significance was unclear 4
• There is concern from preclinical and clinical studies in other contexts that rapid rewarming could be harmful 4

Rewarming Protocol Requirements

• Use a standardized rewarming protocol regardless of chosen rate 4
• Implement continuous temperature monitoring to avoid iatrogenic hyperthermia 4
• Monitor for associated complications including apnea, respiratory distress, and hypoglycemia 4

Quality Improvement Strategies

Implement bundled thermoregulation interventions with multidisciplinary team education and ongoing monitoring to achieve normothermia rates >80%. 6, 5

• Quality improvement initiatives consistently demonstrate significant improvements in admission temperature rates 5
• Successful interventions include standardizing isolette temperature, using chemical warming packs and plastic wrap, and providing regular feedback 6
• One study achieved 96% normothermia rates without increasing hyperthermia through systematic quality improvement efforts 6
• Ongoing education and staff training are essential components for sustainable success 5

Common Pitfalls to Avoid

• Overcorrection leading to hyperthermia: Aggressive warming without continuous monitoring can cause harmful hyperthermia 1
• Inadequate humidity control: Failure to humidify and warm inhaled gases increases insensible water loss in infants <1600g 2
• Delayed intervention: Waiting to implement thermal protection measures rather than starting immediately in the delivery room 2
• Single intervention approach: Relying on one method rather than a combination of interventions reduces effectiveness 1, 2