In this section
The healthcare provider has a crucial role in preventing heat loss and providing a stable thermal environment for neonates and infants. The neutral thermal environment (NTE) has been defined as maintenance of the infants’ temperature with a stable metabolic state along with minimal oxygen and energy expenditure. The NTE is best achieved when infants can maintain a core temperature at rest between 36.5°C and 37.5°C. Thermoregulation is a vital body function, which is reflective of physiological maturity. Effective thermoregulation requires adequate energy stores (primarily glucose), insulation (fat deposits), hypothalamic function and muscle tone. It is widely supported that kangaroo mother care is the most effective method of regulating the neonatal temperature, however frequently in the critical care setting this is unable to be achieved. Furthermore, neonates and infants in the hospital setting frequently require a large portion of their body surface exposed for assessment and procedures which may lead to cold stress. Persistent cold stress is associated with increased morbidity and mortality, thus it is imperative to optimise thermoregulation. In order to ensure the neutral thermal environment is maintained in infants who are unable to achieve this with their own physiological measures, it is essential to provide environmental thermostability by blocking avenues of heat loss, and applying adequate radiant warmth in a suitable cot.
To provide information to healthcare workers on the equipment available to apply assisted thermoregulation support to premature, neonatal and infant patients in the hospital setting, ensuring the most appropriate device is selected for patients will improve delivery of thermostability and optimise outcomes.
It is important to
note that preterm infants are at a higher risk of heat loss via the 4 modes
mentioned above. Preterm infants possess a disproportionate body
mass-to-surface area ratio, reduced thermal insulation in decreased brown
adipose tissue (BAT), a thin epidermis that has increased permeability, poor
vasomotor control and a naturally extended position that exposes a greater body
surface area to the external environment. For these infants, cold stress
will trigger a cascade of physiological responses that further impedes their
transition to extrauterine life.
*Infants who have infection risk or require additional
precautions may be nursed in an incubator to minimise environmental
contamination in some instances. Incubators that are utilised for infection
precautions only may not require the same thermoregulation principles as per
this guideline. Infants may be nursed in a low temperature environmental
setting with light clothing and wraps.
Rectal Temperature is taken on admission to Butterfly Unit to establish a baseline central temperature and patency of the anus. This should not be conducted as routine monitoring on other wards. 1. Place plastic sheath over thermometer2. Dab a small amount of lubrication on end of thermometer3. Insert thermometer 2cm into infant’s anus (1cm for preterm infant). Over-insertion may cause bowel perforation. 4. Turn thermometer on5. Wait for 5 seconds post Celsius sign flashing6. Remove thermometer7. Clean with alcoholAxilla Temperature is taken thereafter the initial rectal temperature. 1. Position the tip of the thermometer in the middle of the axilla2. Lock the tip under the arm at a 35 - 45 degree angle in relation to the arm, using the arm to slightly apply pressure. 3. Turn thermometer on.4. Wait 3 minutes for an accurate temperature reading.5. Parents can be taught to safely take their baby’s temperature using the same process.
Hourly until stable for 4 hours on:
When infant’s temperature is stable (for at least 4 hours prior):
Frequency of probe assessment:
Probe placement: Optimal temperature probe placement for central surface monitoring is on the abdomen for a supine infant, ideally over the liver region; or on the back over the flanks if positioned prone. The probe should NOT be placed on areas of brown adipose tissue (back, axillae, scapula, neck and kidneys) as brown fat metabolism is activated to generate heat during cold stress, delaying vasoconstriction at these sites, thus there will be a delay in detection of declining temperature stability. Additionally, bony prominences should be avoided due to reduced sensitivity to temperature changes. It is imperative that the probe is not placed between the mattress and the infant, as this will create a false high reading, resulting in inadvertent cooling, and also poses a risk for pressure area development. The probe should be sited away from transcutaneous gas monitoring transducers. Ensure the probe is not in contact with any wound dressings. It may be normal for a variance of skin probe temperature reading and axillary temperature of 0.5 – 1.0°C, and setting servo control should target appropriate skin temperature, not axillary temperature in the instance of a discrepancy.The probe should be resited every 8 hours, or upon repositioning of the infant, with care taken when removing adhesive patch to minimise skin trauma. Skin adhesive remover (e.g. Niltac™) wipes may be utilised to aid with removal. Upon application it may take 4 - 5 minutes for temperature monitoring to stabilise. Servo control is the preferred mode for all neonates and infants requiring assisted thermoregulation. Servo control maintains the infant’s temperature within a specific range by adjusting heat output to achieve pre-set skin probe temperature. This relies on appropriate placement of the skin probe, and continuous observation to ensure the probe remains well adhered to the skin and the heat output is not widely fluctuating. If there is a significant change in heat output from the device, closer assessment may be required to ensure probe remains well adhered. Increased thermoregulation requirements may be indicative of a deterioration and routine observations may need to be more frequent. 1. Infants weighing <1750grams – Target axillary temperature of 36.8°C2. Infants weighing >1750grams – Target axillary temperature of 36.5°CManual control is where a constant environmental temperature is set with continuous, unadjusted heat output. This mode may be used on all devices to pre-warm for an expected admission, when a temperature probe needs to be removed temporarily for a procedure, or when aiming to wean from an incubator to an open cot. This mode is not recommended for long-term use in other instances, as there is an increased risk of temperature instability in manual control. Air temperature must be set higher than ambient temperature of room. The temperature probe should remain insitu as a guide for nursing staff to monitor temperature continuously, and adapt environmental temperature accordingly. Refer to environmental temperature for gestational age and weight chart.
Generally speaking, the smaller infants in each group will
require a temperature in the higher portion of the range, and for each age
range, the younger infants generally require the higher temperature setting for
Infants who do not fit the age and weight ranges for this
chart should have the incubator set at 29°C with minimal clothing for
observation as a starting point.
This data has been taken from GHS Neonatal Intensive Care
Unit Resident Handbook 2018-2019, adapted from Scopes JW, et al: Minimal rates
of oxygen consumption in sick and premature infants, Arch Dis Child 41: 407,
patient’s temperature is <36.5°C and not being actively cooled,
initiate the following:
If the patient’s temperature is >37.5°C, initiate the
Within the flowsheets of EMR, temperatures can be documented within the ‘observations’ section with the method of temperature selected from the drop-down options below. Furthermore, within ‘thermoregulation’, select either incubator or radiant warmer, and document the ‘skin temperature probe reading’, ‘skin temperature site’ and ‘set temperature/air temperature’ hourly.
Infants can be transferred to an open cot once they have met the following criteria:
Once the infant meets the above criteria and discussion has taken place between the bedside nurse, medical team & AUM, the infant may be transferred to an open cot by using the following steps as a guide:
The evidence table for this guideline can be viewed here.
Please remember to read the disclaimer.
The development of this nursing guideline was coordinated by Sarah Gardner, CSN/CNS, Butterfly Ward, and approved by the Nursing Clinical Effectiveness Committee. Updated June 2020.