Management (WARM)

Thermoregulation is crucial in neonates because their immature bodies lose heat quickly and cannot regulate temperature effectively, putting them at risk of hypothermia, metabolic stress, and serious complications.

Hypothermia is when an infant’s temperature is below normal range (36.5°C). Hypothermia can also cause vasoconstriction, further impairing oxygen delivery Essential for preventing hypothermia, especially in vulnerable and preterm infants as cold stress which can worsen respiratory distress, leading to exacerbate hypoxia and hypoglycaemia. If an infant becomes hypothermic, they will increase their metabolic demands, therefore increasing the glucose consumption. Premature infants have less ability to regulate body temperature, making thermoregulation critical for their overall health and stability. They have limited fat stores and immature thermoregulation, making them prone to heat loss.

Hyperthermia is when an infant’s temperature is above normal range (>37.5°C), this can be caused by environmental factors like excessive clothing or a warm environment, rather than an underlying disease.

Strategies

Maintaining normothermia is critical in the care of premature or hemodynamically unstable neonates, as they are particularly vulnerable to heat loss. Effective thermal management helps prevent complications such as hypothermia, hypoglycaemia, and hypoxia.

Interventions

Interventions to support thermoregulation include the use of incubators, which provide a controlled and humidified environment; radiant warmers, which offer immediate warmth during procedures or resuscitation; and open cots with additional thermal aids for stable infants. Each method is selected based on the neonate’s condition, gestational age, and care requirements.

Incubators

Incubators provide a NTE which will minimise metabolic and oxygen expenditure. They are used to maintain a controlled thermal environment and enable visualisation of the hemodynamically unstable infant or preterm infants. Infants are generally nursed naked with nappy only, which enables visualisation, incubators can be used in manual mode were a desired Neutral Thermal Range (NTR) is set based on infants’ weight and hours of age or servo-controlled mode, where probe that is attached to the incubator is placed on the infant (generally abdomen) and the incubator will heat up or cool down to keep infant at desired (set) temperature.

Indications:

• • Prematurity – all preterm infants less than 32 weeks’ gestation
  • And or less than 1800 grams
  • Hemodynamically unstable sick term infant
  • Respiratory distressed- nurse naked, enables visualisation of work of breathing (WOB), prone positioning- if not contraindicated (contraindications include un-monitored infant, umbilical lines)
  • Nurse naked with nappy- enables visualisation of work of breathing (WOB)
  • Phototherapy- enables maximum exposure of infant’s skin to lights
  • Oxygen therapy- enables ambient oxygen titrated to infants needs to be circulated throughout incubator
  • Humidity-can be used to deliver humidity to the preterm infant to prevent TEWL in the first 14 days of life.

Open cots

Open cots are used for haemodynamically stable infants.

Indications:

• • Greater than 32 weeks’ gestation
  • And or greater than 1800 grams
  • Layers of clothing and blankets adjusted according to the infant’s needs

Radiant warms

Radiant warms provide infrared heat to warm the naked infant. The heat generated must offset the radiant heat lost by the infant to the environment. Can be used in either a manual mode or servo controlled.

Nowadays many radiant warmers are hybrid cots, that can be converted into incubators once infant is stabilised.

Indications:

• • Suitable for stabilising infants.
  • Infants requiring multiple procedures.
  • Larger infants

(RCH 2020, Gardner et al 2021, Kain and Mannix 2023)

Monitoring temperature

Continuous or frequent monitoring of the neonate’s temperature is essential to ensure they remain within a safe thermal range and to promptly detect any signs of hypothermia or hyperthermia.

Monitor axillary temperature: On admission then, check temperature 4 hourly and adjust environmental conditions accordingly if temperature deviated from norm, then intervention required and reevaluate in one hour. if cold on admission check hourly & skin (vasoconstricted, cool periphery?) until normal & stable, adjust incubator accordingly. Behaviour – lethargic if cold?

Temperature below 36.5ºC- and being nursed in incubator within Neutral thermal range (NTR) increase incubator temperature by 0.5ºC hourly whilst checking axilla temperature hourly until 2 consecutive temperatures above 36.5ºC.

If nursed in an open cot then layers can be added whilst checking axilla temperature hourly until 2 consecutive temperatures above 36.5ºC.

Temperature above 37.5ºC- and being nursed in incubator within NTR decrease incubator temperature by 0.5ºC hourly whilst checking axilla temperature hourly until 2 consecutive temperatures between 36.5ºC and 37.5ºC.

If nursed in an open cot then layers can be removed whilst checking axilla temperature hourly until 2 consecutive temperatures between 36.5ºC and 37.5ºC.

Prevent heat loss of heat via radiation, convection, conduction & evaporation weigh using scales with warm wraps, warm stethoscope

If in incubator adjust settings to keep axillary temperature between 36.5-37.5°C. keep side doors closed of incubator during procedures use portholes or radiant warmer.

Minimise Heat Loss:

1. • Use bubble wrap to prevent evaporative heat loss.
   • Weigh using scales with warm wraps, warm stethoscope
   • Provide hat and pre-warmed linen in the incubator
   • Positioning to mins heat loss, flexed & supported reduces surface area
   • Nesting
   • Minimise handling, cluster cares

Skin to Skin Contact: Facilitate skin-to-skin contact (kangaroo care) in the hemodynamically stable infant when appropriate to support thermoregulation and bonding

Documentation: Record the infant’s temperature 4 hourly unless deviated from norm, then intervention required and reevaluate in one hour, note any deviations from normal and escalate accordingly

(RCH 2020, Gardner et al 2021, Kain and Mannix 2023)

Evaluation

• • Normothermic, well perfused & warm skin including periphery, pink,
  • Axillary temperature stabilizes within 36.5-37.5°C.
  • Infant remains warm to touch with no signs of cold stress (e.g., hypoglycaemia, lethargy).
  • Stable blood glucose levels (cold stress can exacerbate hypoglycaemia).
  • Temperature stabilises within normal range, no signs cold stress.

(RCH 2020, Gardner et al 2021, Kain and Mannix 2023)

Managing the thermal environment in some more commonly seen SCN presentations

*** this is a guide only:  Always refer to local policy and or guidelines to ensure you are practicing within hospital frameworks and your scope of practice***