We have detected you are using Internet Explorer. To provide the best and most secure experience, please use a modern browser as we do not support Internet Explorer.

The protective role of pyrexia

Are we doing the right thing when we reach for paracetomol or ibuprofen in response to a fever, or does that fever have benefits in helping our body to fight the infection?

Who hasn’t reached for the paracetamol when feeling under the weather with a cold or a patient presents with a fever? Are we doing the right thing, or does that fever have benefits in helping us fight the infection? Hippocrates claimed that

Those who cannot be cured by medicine or surgery can be cured by heat; and those who cannot be cured by heat are to be considered incurable - Geddes 2020

The HEAT trial (Young 2015) demonstrated that administration of paracetamol to patients with an infection/sepsis in the ICU did not reduce mortality.  An elevated body temperature in response to infection sets in motion a series of mechanisms that regulate the immune system, these processes are important for fighting the infection, and administration of antipyretics such as paracetamol and ibuprofen will impede the body’s ability to perform this vital function.

In the presence of infective agents such as bacteria and viruses, pyrogens or fever producing proteins are released.  These pyrogens act on the hypothalamus to release prostaglandin which resets the hypothalamic thermostat to a higher temperature resulting in an elevated body temperature. 

In response to the release of pyrogens, the hypothalamus 

  1. Conserves heat by triggering vasoconstriction (this has the added benefit of decreasing vascular pooling and optimising perfusion to organs) and 
  2. Increases heat by triggering shivering 

(Image adapted from Romera 2018)

How high is too high?

So why does paracetamol or ibuprofen routinely get prescribed and administered for fever?  There is a downside to fever, for every 1℃ our body temperature increases there is a 10% increase in metabolism (Walter et al 2016).  Our heart rate and respiratory rate increase and in some patients such as those with cardiac, respiratory or renal comorbidities this increased workload on the heart leads to complications.

This, and the fact that we ‘feel’ better, has led to the routine administration of antipyretics when fever is present.

Why you need to hesitate instead of administrate:

  • The immune system works more efficiently when temperatures are elevated 
    • cytokine production is increased increasing the body’s ability to eliminate the pathogen
    • Macrophages, neutrophils and T-cells respond faster and have an improved capacity to engulf and destroy pathogens at temperatures between 37.5 - 39.4℃
  • Bacteria and viruses replicate easier at lower temperatures, an elevated body temperature will slow the multiplication rate reducing the severity of infection

(Walter et al 2016)

Next time you have a febrile patient, before you reach for the Paracetamol, ask yourself:

Is this going to helpful or harmful?

If you found this topic of interest, you will enjoy the learning in our programs focusing on care of the paediatric patient, clinical deterioration and sepsis series. 

For a full list of events and courses please visit https://medcast.com.au/critical-care

Register for the Paediatric Nursing Essentials or for some byte sized grabs of education on the latest developments in ciritical care, join us in our new series Critical Bytes:

References and Further Reading:

Fajgenbaum D., & June C., 2020 Cytokine Storm N Engl J Med 383:2255-2273 

Geddes L. (2020) The fever paradox New Science 246 (3277), 39-41 

Liu Q., Zhou Y., and Yang Z. (2016) The cytokine storm of severe influenza and development of immunomodulatory therapy Cell Mol Immunol 13, 3-10 

Romero M. (2018) How does fever occur? Clinic Barcelona Hospital Universitari 

Walter E.J., Hanna-Jumma S., Carretto M., & Forni L. (2016) The pathophysiological basis and consequences of fever. Critical Care 20 (200) 

{{commentCount}} comment(s). You must be logged in and AHPRA verified to view and comment. LOG IN

Susan Helmrich

Susan is the Head of Nursing Education at Medcast.

DipAppScNsg, BN, CritCareCert, CoronaryCareCert, TraumaNsgCareCert, CertIV(TAE), MN(Ed), and GradCert(Ldrshp & Mgt).

The latest healthcare news from medcast

Clinical Opal #5 - Red eye
Clinical Opal #5 - Red eye

Fatima is a 53-year-old human resources manager who presents to you with a 24-hour history of a painful red left eye.

Grants for GPs & Nurses - are you eligible?
Grants for GPs & Nurses - are you eligible?

To help lessen the financial burden of keeping up with CPD, rural and remote health professionals (MMM 3-7) who would normally be required to travel considerable distances to attend courses, can access a range of state-based funding.

Helping new mums during COVID
Helping new mums during COVID

How one small not-for-profit in Sydney is helping new mums during Covid-19.

Clinical Opal #4 - Cough and fever
Clinical Opal #4 - Cough and fever

Jill is a 64-year-old retired accountant who presents to you with her concerned husband, Michael. Jill is usually fit and well apart from a history of well controlled hypertension on perindopril.

Training with Cognitive Aids
Training with Cognitive Aids

By using a well structured and easy to follow aid, the risk of error is reduced and evidence based practice is more likely to be actioned.

A GP's perspective: What I learned at the recent free Hot Topics webinar - Asthma
A GP's perspective: What I learned at the recent free Hot Topics webinar - Asthma

Hot Topics free webinar presenter in New Zealand discovers children with asthma admissions aren't necessarily recorded in practice.

Clinical Opal #3 - Sudden hearing loss
Clinical Opal #3 - Sudden hearing loss

Adam is a 34-year-old maths teacher who is usually fit and well, with no significant past medical history.

What trans kids need from health care professionals
What trans kids need from health care professionals

Our bad experiences of mental health care with health professionals

Total Intravenous Anaesthesia (TIVA)
Total Intravenous Anaesthesia (TIVA)

Total Intravenous Anaesthesia (TIVA) has become an increasingly popular choice for anaesthesia, as alternatives to volatile agents. Surgical technique advancements and increasing utilisation of day hospital centres have created an environment wher...

Clinical Opal #2 - Painful Leg
Clinical Opal #2 - Painful Leg

Dave is a 33-year-old carpenter who presents to you with a painful red leg.

Coping with Covid: my report card says “Could do better”
Coping with Covid: my report card says “Could do better”

What have we learned from the last lockdown? Does having a job and being an introvert make it any easier?

Clinical Opal #1 - Medications for Anxiety
Clinical Opal #1 - Medications for Anxiety

Harriet is a 22-year-old university student who presents to you with severe anxiety.

School Teachers: The Forgotten Frontline Workers of COVID-19
School Teachers: The Forgotten Frontline Workers of COVID-19

School teachers have been hit hard by COVID-19. Since the start of 2020, teaching roles and demands have changed significantly. One key change was the rapid addition of new online methods of teaching. This was crucial to cater for students sti...

Music as therapy – and not just for us!
Music as therapy – and not just for us!

“What a night...we needed it!” This was one of many responses to a musical soiree I held at our home on a Sunday evening in late May. The flood in expressions of gratitude reflected how much we all valued playing and reconnecting. This was an in...

Emergencies in General Practice
Emergencies in General Practice

Kids have been falling out of trees ever since there were kids (and trees). As a result, head trauma has been a common childhood injury for millennia.

Perioperative Anaphylaxis
Perioperative Anaphylaxis

Once anaphylaxis has been identified, immediate treatment is required to stop the allergic cascade from producing histamines, prostaglandins and cytokines, and manage the effects of these agents. Management will include immediate treatment, refrac...

Writing Our Stress Away
Writing Our Stress Away

As you may know, I’m a big fan of writing as a stress management tool. There’s even evidence to support the idea!

Why you should use an ABCDE approach to patient assessment
Why you should use an ABCDE approach to patient assessment

The ABCDE approach is the most recognised tool for rapid patient assessment, it allows us to recognise life-threatening conditions early and provides a systematic method that focuses on identifying problems and implementing critical interventions ...

Tips for integrating digital mental health into clinical practice
Tips for integrating digital mental health into clinical practice

In late 2020, I was lucky enough to start in a new role at The Clinical Research Unit for Anxiety & Depression (CRUfAD) at St Vincent’s Hospital Sydney. This was the year in which there were many challenges and barriers to accessing mental health ...

Working Towards Wellbeing – Mental Health Skills Videos for the Time Poor
Working Towards Wellbeing – Mental Health Skills Videos for the Time Poor

Do you ever struggle with explanations around mental health interventions? Do you need to learn some interventions that may be useful in your own life?

Join Medcast. It's free and you'll get instant access to essential healthcare news, research and more.

Already a member? Log In