Define Homeostasis and Describe How It Relates to Hyperthermia

Introduction

Aim

Definition of Terms

Temperature Ranges

Assessment

At Risk Patient Groups

Management

Special Considerations

Companion Documents

Links

Evidence Table

References

Introduction

Temperature management remains a significant component of hospital care for all neonatal and paediatric patients. Body temperatures outside normal ranges may be indicative of underlying disease processes or clinical deterioration, and should be identified within a timely manner. Maintaining a stable body temperature within normal ranges assists in optimising metabolic processes and bodily functions. Therefore, minimising environmental factors within the hospital setting which may result in unnecessary body temperature fluctuations is further important.

Aim

To assist healthcare professionals in undertaking the appropriate assessment and potential management of neonatal and paediatric body temperatures, at The Royal Children's Hospital.

Definition of Terms

• Normothermia: Body temperature within normal values.
  Exact normal temperature ranges differ between individuals and can be influenced by some genetic and chronic medical conditions. It is important to ascertain the baseline for individual patients in order to identify abnormal body temperature deviations.
  
• Pyrexia: An elevated body temperature due to an increase in the body temperature's set point. This is usually caused by infection or inflammation. Pyrexia is also known as fever or febrile response.
  Some causes of fevers do not require medical treatment, whilst other causes need to be identified and treated.
  
• Hyperthermia: An elevated body temperature due to failed thermoregulation. This occurs when the body produces and/or absorbs more heat than it can dissipate.
  
• Heat stroke: A presentation of severe hyperthermia. Thermoregulation is overwhelmed by excessive metabolic production and environmental heat, in combination with impaired heat loss. This is uncommon within an inpatient setting.
  
• Low temperature: A lowered body temperature, where the body loses heat faster than it can produce heat.
  
• Hypothermia: An abnormally low body temperature, where the body temperature drops below a safe level. Both low temperatures and hypothermia can be caused by environmental factors, metabolic complications, disease processes, or can be medically induced.
  

Temperature Ranges

Classification	Neonates	Paediatrics*
Low temperature (or hypothermia)	<36.5⁰C	<36⁰C
Normothermia	36.5 - 37.5⁰C	36 - 37.5⁰C
Low grade fever (or normothermia)	37.6 - 37.9⁰C	37.6 - 37.9⁰C
Fever (or hyperthermia)	≥ 38⁰C	≥ 38⁰C

*Significant variation of suggested temperature values and ranges exists within current literature. The values presented in this table are derived from a collaboration of multiple sources and expert opinions, and should be utilized as a guideline only. Exact normal temperature ranges differ between individuals. It is important to ascertain an individual's baseline in order to identify abnormal body temperature deviations, and to evaluate these in the context of other vital signs and overall patient presentation.

Please note, any febrile child who appears seriously unwell should have a thorough assessment and their treating medical team notified, irrespective of the degree of fever.
In infants <3 months, hypothermia or temperature instability can be signs of serious illness.

Assessment

Body temperature should be measured on admission and four hourly with other vital signs, unless clinically indicated for more frequent measurements.
Body temperatures falling outside normal ranges should be monitored and further managed where appropriate until normothermia is achieved.

When assessing body temperatures, it is important to consider patient-based and environmental-based factors, including prior administration of antipyretics and recent environmental exposures.
Body temperature should always be evaluated in the context of other vital signs and overall patient presentation.

Methods of body temperature measurements:

Due to temperature variation between body sites, ideally the same route should be used for ongoing patient observations, as to allow for accurate temperature trend evaluation. Document the route used in EMR.

0-3 months: Axillary Route
Axillary digital thermometer is the preferred method for this age group, in most cases.

   Procedure:

1. Place thermometer tip in the centre of the armpit over the axillary artery, ensuring skin is dry and intact prior to probe placement.
   
2. Place the patient's arm securely against their body.
   
3. Turn thermometer on. For a more accurate reading, wait >3 minutes with thermometer in situ before obtaining a measurement.

0-3 months: Rectal Route (if requested)
In special cases, a rectal temperature may be required for a more accurate assessment of body temperature.
This should be performed only if approved by medical staff, with ANUM involvement.
Rectal measurements should be avoided within the oncology population and in patients with low platelets, coagulopathy, or perineal trauma and pelvic area surgery, due to the increased risk of bowel perforation.

   Procedure:

1. Place plastic sheath over thermometer.
   
2. Dab a small amount of lubricant on end of thermometer.
   
3. Carefully insert thermometer 2cm into the infant's anus (1cm for pre-term infant). Over-insertion may cause bowel perforation.
   
4. Turn thermometer on.
   
5. Wait for 5 seconds post Celsius sign flashing before taking a recording.
   
6. Remove and clean thermometer with alcohol.

>3 months: Tympanic Route
Tympanic thermometer is the preferred method for this age group.

   Procedure:

1. Gently insert probe into ear canal until the canal is entirely sealed off, ensuring the tip is facing the eardrum.
   
2. Press the thermometer button and wait for the beeps.
   
3. If ears have been covered (eg. headphones/beanie), remove items and wait until ear canal is cooled before taking measurement. If a patient's ear canals are too small to properly insert the tympanic probe, consider an axillary thermometer route instead.
   

Notes:
If the patient has been exposed to cold conditions, allow for adequate time for patient to equilibrate to room temperature before measuring body temperature.
Both axillary and tympanic routes measure temperatures lower than true core body temperature.
Temperature measurement frequency may differ in sub-speciality areas, such as within the Emergency Department, critical care and peri-operative areas. Please refer to specific department guidelines for further information.

At Risk Patient Groups

The following patient populations are at an increased risk of being unable to maintain normothermia:

• Neonates and young infants
  
• Peri and post-operative patients
  
• Burns patients
  
• Trauma patients
  
• Neurologically compromised patients
  

Management

Preventative Approaches

A patient's surrounding environment can greatly impact their ability to maintain an otherwise stable body temperature. Acknowledging and minimising environmental influences on thermoregulation is important for all paediatric patients, especially the neonatal and at risk patient populations.

The table below outlines approaches nurses, clinicians and families can utilise towards minimising preventable heat transfer from patients to their surroundings.

Mode	Definition	Clinical Scenario	Preventative Management
Evaporation	Heat loss occurring during conversion of liquid to vapour	Sweat, incontinence Wet or oozing dressings	Keep patient dry Remove wet clothing, replace wet dressings if appropriate
Convection	Transfer of heat from the body surface to the surrounding air via air current	Air drafts in room	Relocate patient away from draughts, close door
Conduction	Transfer of heat from one solid object to another solid object in direct contact	Cold blankets, cold weighing scales	Cover cold surfaces with pre-warmed towel or blanket
Radiation	Transfer of heat to cooler solid objects not in direct contact with the body	Nearby cold windows or walls	Relocate patient away from cold surfaces Close blinds on window

Neonatal Management

Paediatric Management

Notes:

• Sepsis: Early recognition and initial management of sepsis in neonates and paediatrics is paramount, and if left untreated can lead to severe morbidities and mortality.  For further information on sepsis recognition and management of neonates and paediatrics, please see *Link: SEPSIS- assessment and management, RCH CPG*
  
• Bair Hugger devices: If using a forced air warming device, the temperature of the device should not be set to >32⁰C in the inpatient setting. The patient's temperature should be rechecked at a minimum of every 30 minutes or if the patient is <6 months, a minimum of every 15 minutes whilst forced air warming in use, as patients are at a risk of overheating. Check that the blanket is connected to the device correctly as patients are at risk of burns.
  
• If applicable, refer to individual department guidelines for management of specific patient populations, eg. Febrile Neutropenia pathway. See Special Considerations section below.
  

Special Considerations

The following patient populations may require more specific interventions and/or differing management when body temperature falls outside traditionally normal values:

• Febrile Neutropenic patients
  
• Therapeutic hypothermic patients
  
• Therapeutic hypothermic neonates
  
• Patients with chronic conditions causing lower baseline body temperatures
  Some patient populations have conditions that affect their basal metabolic rates and thus, have unique normal temperature ranges. It is important to ascertain these individual's normal temperature fluctuations in order to identify abnormal readings and manage appropriately.
  
• Perioperative and Postoperative Patients
  
  • Preoperatively
    
    • Ensure temperature is taken on admission and patients are appropriately dressed and warm preoperatively.
    • Provide a warm blanket as appropriate.
    • Consider forced air warming (Bair Hugger) for patients undergoing extensive surgery.
      
  • Recovery
    
    • Ensure temperature is taken on admission to PACU
      
    • Initiate active warming via forced air warming (Bair Hugger) if neonatal patient temperature is <36⁰C (if not in Ohio/Isolette) or paediatric patient temperature is <35.5⁰C.
      
    • Temperature should be taken every 5 minutes whilst a patient is receiving active warming.
      
    • If overheating or burns occur, stop active warming and seek anaesthetic review (treating or in charge). Cool patient if appropriate. Document event via EMR and complete VHIMS.
      
    • Discharge temperature is ≥36.6⁰C for neonatal patients and ≥36⁰C for paediatric patients.  Ensure clinical indicators are completed and active warming interventions are documented in EMR.
      
    • Patients with chronic conditions which cause lower baseline body temperatures should return to their baseline prior to transfer to ward. This baseline temperature should be discussed with parents/caregivers and communicated to the receiving ward or day surgery.
      
    • If the post-operative temperature is <36⁰C but ≥35.5⁰C, the patient is rousable and all other vital signs are stable and within normal range, they can be transferred to the ward.  If clinically indicated, forced air warming can be made available for ward to continue to use. This should be discussed with parents/caregivers and communicated to admitting ward.

Companion Documents

• Nursing Assessment (CPG (Nursing))
  https://www.rch.org.au/rchcpg/hospital_clinical_guideline_index/Nursing_assessment/
  
• Febrile Child (state-wide CPG):
  https://www.rch.org.au/clinicalguide/guideline_index/febrile_child/
  
• SEPSIS (state-wide CPG):
  https://www.rch.org.au/clinicalguide/guideline_index/SEPSIS_assessment_and_management/
  
• Febrile Neutropenia (state-wide CPG):
  https://www.rch.org.au/clinicalguide/guideline_index/Fever_and_suspected_or_confirmed_neutropenia/

Additional Useful Links

RCH Kids Health Info Fact Sheet on Fever in Children
https://www.rch.org.au/kidsinfo/fact_sheets/fever_in_children/

Evidence Table

Temperature Management Nursing Guideline Evidence Table 2019. 

References

• Asher, C., & Northington, L. K. (2008). Position statement for measurement of temperature/ fever in children. Journal of Pediatric Nursing, 23(3), 234-236. doi: 10.1016/j.pedn.2008.03.005
  
• Barbi, E., Marzuillo, P., Neri, E., Naviglio, S., & Krauss, B. S. (2017). Fever in Children: Pearls and Pitfalls. Children, 4(9), 81-99. doi:10.3390/children4090081
  
• Bharti, P., Chauhan, M., & Ahmed, K. (2017). Comparison of rectal, infra-red tympanic and infra-red skin temperature in term neonates. International Archives of Integrated Medicine, 4(3), 43-49. Retrieved from https://search-ebscohost-com.ezp.lib.unimelb.edu.au/login.aspx?direct= true&db=a9h&AN=122002190&site=eds-live&scope=site
  
• Davie, A., & Amoore, J. (2010).  Best practice in the measurement of body temperature. Nursing Standard, 24(42), 42-49.  doi: 10.7748/ns2010.06.24.42.42.c7850
  
• Derieg, S. (2017). An overview of perioperative care for paediatric patients. The Journal of Perioperative Nursing in Australia, 30(3), 23-29. doi:10.26550/303/23-29
  
• Dougherty, L., Lister, S., & West-Oram, A. (2015). Observations. In The Royal Marsden Manual of clinical nursing procedures, 9th ed. (pp. 534-540). West Sussex, UK: The Royal Marsden NHS Foundation Trust.
  
• El-Radhi A.S. (2018). Measurement of body temperature. In El-Radhi A. (Ed.) Clinical Manual of Fever in Children (pp. 69-84). Retrieved from https://doi.org/10.1007/978-3-319-92336-9_4
  
• Freer, Y., & Lyon, A. Temperature monitoring and control in the newborn baby. (2011). Paediatrics and Child Health, 22(4), 127-130. doi:10.1016/j.paed.2011.09.002
  
• Hay, A. D., Costelloe, C., Redmond, N. M, Montgomery, A. A., Fletcher, M., Hollinghurst, S., & Peters, T. J. (2008). Paracetamol plus ibuprofen for the treatment of fever in children (PITCH): randomised controlled trial. British Medical Journal, 337(7672), 729-733. doi:10.1136/bmj.a1302
  
• Işler, A., Aydin, R., Güven, Ş. T., & Günay, S. (2014). Comparison of temporal artery to mercury and digital temperature measurement in pediatrics. International Emergency Nursing, 22(3), 165-168. doi:10.1016/j.ienj.2013.09.003
  
• Knobel, R. B. (2014). Fetal and neonatal thermal physiology. Newborn and Infant Nursing Reviews, 14(2), 45-49. doi: 10.1053/j.nainr.2014.03.003
  
• Leduc, D. Woods, S. (2013).Position statement: temperature measurement in paediatrics. Canadian Paediatric Society. Retrieved from https://www.cps.ca/en/documents
  
• National Institute for Health and Clinical Excellence (NICE). (2013). Feverish illness in children: assessment and initial management in children younger than 5 years. London: Royal College of Obstetricians and Gynaecologists. Retrieved from https://www.nice.org.uk/guidance/cg160
  
• Oguz, F., Yildiz, I., Varkal, M. A., Hizli, Z., Toprak, S., Kaymakci, K., … Unuvar, E. (2018). Axillary and tympanic temperature measurement in children and normal values for ages. Pediatric Emergency Care, 34(3), 169-173. doi:10.1097/PEC.0000000000000693
  
• Printz, V., Hobbs, A. M., Teuten, P., & Paul, S. P. (2016). Clinical update: assessment and management of febrile children. Community Practitioner, 89(6), 32-37.
  
• Trevisanuto, D., Testoni, D., & de Almeida, M. F. (2018). Maintaining normothermia: why and how? Seminars in Fetal & Neonatal Medicine, 23(5), 333-339.  doi:10.1016/j.siny.2018.03.009
  
• Weiss, S. L., & Pomerantz, W. J. (2019). Septic shock in children: rapid recognition and initial resuscitation (first hour). Up to Date. Retrieved from https://www.uptodate.com/contents/septic-shock-in-children-rapid-recognition-and-initial-resuscitation-first-hour

 Please remember to read the disclaimer.

The development of this nursing guideline was coordinated by Elizabeth Cooke, RN, ED, and approved by the Nursing Clinical Effectiveness Committee. Updated August 2019.

Define Homeostasis and Describe How It Relates to Hyperthermia

Source: https://www.rch.org.au/rchcpg/hospital_clinical_guideline_index/Temperature_management/

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