Sepsis: Signs and Symptoms


Published: 09 May 2023

How does a patient die from sepsis? What happens to their body, vessels and organs?

When someone experiences an infection, every cell of their body is compromised. With the right clinical assessment skills and knowledge, it’s possible to identify sepsis early and save lives.

This article has been updated to reflect the Surviving Sepsis Campaign Guidelines 2021.

Note: This article is intended as a refresher and should not replace best-practice care. Always refer to your local policy on recognising and responding to sepsis.

What is Sepsis?

Sepsis is an overactive response to an infection that causes the body to damage its own organs and tissue (Sepsis Alliance 2022).

Sepsis can be caused by any infectious pathogen (WHO 2020).

When chemicals are released from the infection into the systemic circulation, the body then recognises the foreign body and the inflammatory process begins, leading to coagulation (blood clotting) and hypoperfusion (decreased blood supply to the organs). This impaired blood supply starves the organs of oxygen, causing significant damage (NIGMS 2019).

Sepsis is a life-threatening medical emergency that can lead to septic shock, multiple organ failure and potentially death.

Sepsis is estimated to affect 55,000 Australians annually, resulting in at least 8,700 deaths. Sepsis is also involved in up to half of all deaths occurring in hospital (Healthdirect 2021).

sepsis diagram
Sepsis is an overactive response to an infection causing the body to damage its own organs and tissue.

Who is at Risk of Sepsis?

Sepsis doesn’t discriminate; anyone from babies to older adults can develop it. It is, however, more common and dangerous in those with weakened immune systems, older adults with multiple comorbidities, the very young, and individuals who are already unwell (Mayo Clinic 2023).

Identifying Sepsis

The many signs and symptoms of sepsis include abnormalities in the individual’s body temperature, heart rate, respiratory rate, hypotension and white blood cell count, in addition to hypoxaemia, oliguria, lactic acidosis, elevated liver enzymes and altered cerebral function (Sepsis Alliance 2023).

The Surviving Sepsis Campaign Guidelines 2021 recommend using one of the following sepsis screening tools to identify sepsis:

  • Systemic inflammatory response syndrome (SIRS) criteria
  • National Early Warning Score (NEWS)
  • Modified Early Warning Score (MEWS).

Note: Sequential Organ Failure Assessment (SOFA) can be used as a sepsis screening tool, however, the use of the quick Sequential Organ Failure Score (qSOFA) is not recommended due to its poor sensitivity (Evans et al. 2021).

Systemic Inflammatory Response Syndrome (SIRS) Criteria

If the patient meets at least two of the following criteria, they meet the criteria for SIRS:

  • Temperature > 38°C or < 36°C
  • Heart rate > 90
  • Respiratory rate > 20 or PaCO2 < 32 mmHg
  • White blood cell count > 12,000 / mm³ or < 4,000 / mm³ or > 10% bands.

(Medscape 2020a)

National Early Warning Score (NEWS)

NEWS involves giving six physiological parameters a score between 0 and 3:

Physiological parameter 3 2 1 0 1 2 3
Respiration rate (breaths per minute) ≤8 9-11 12-20 21-24 ≥25
SpO2 Scale 1 (%) ≤91 92-93 94-95 ≥96
SpO2 Scale 2 (%) ≤83 84-85 86-87 88-92
≥93 on air
93-94 on oxygen 95-96 on oxygen ≥97 on oxygen
Air or oxygen? Oxygen Air
Systolic blood pressure (mmHg) ≤90 91-100 101-110 111-219 ≥220
Pulse (per minute) ≤40 41-50 51-90 91-110 111-130 ≥131
Consciousness Alert CVPU
Temperature (°C) ≤35.0 35.1-36.0 36.1-38.0 38.1-39.0 ≥39.1

(Adapted from RCP 2017a)

These scores should be added up, and the total will becomes the patient’s aggregate NEW score. There are four levels of clinical alert based on the patient’s aggregate NEW score:

  • Low NEW score (1-4)
  • Single red score (a score of 3 in any one parameter)
  • Medium NEW score (5-6)
  • High NEW score (≥7).

(RCP 2017b)

Modified Early Warning Score (MEWS)

The MEWS uses physiological parameters to identify patients at increased risk of catastrophic deterioration.

Physiological parameter 3 2 1 0 1 2 3
Systolic blood pressure (mmHg) ≤70 71-80 81-100 101-199 ≥200
Heart rate (beats per minute) ≤40 41-50 51-100 101-110 111-129 ≥130
Respiration rate (breaths per minute) <9 9-14 15-20 21-29 ≥30
Temperature (°C) <35 °C 35-38.4 °C ≥38.5 °C
AVPU Neurological Score Alert Reacts to voice Reacts to pain Unresponsive

(Medscape 2020b)

These scores are added together, and a total MEWS score of ≥4 requires escalation of care (CHHS 2018).

The Importance of Identifying Sepsis

Early identification and treatment of sepsis is crucial in preventing patient death.

Sepsis is often misdiagnosed, as it generally comprises non-specific symptoms. The longer sepsis is left untreated, the more severe it becomes and the risk of mortality increases. Therefore, it is crucial to adhere to protocol designed to identify and treat sepsis as soon as possible (D'Orazio Peterson 2013).

Nurses play an essential role in the care of patients with sepsis, with nurse-led initiatives having demonstrated a decrease in mortality, ICU readmission and length of hospital stay (Kleinpell et al. 2019).

What to do When Sepsis is Recognised

The Surviving Sepsis Campaign is an international initiative aimed at reducing the global mortality of sepsis. Their Hour-1 Bundle guideline sets out five tasks that should be commenced (though may not necessarily be finished) within the first hour of sepsis recognition as part of the initial resuscitation. They are:

  1. Measure the patient’s lactate level.
    • Remeasure lactate if the initial level is elevated (> 2 mmol/L).
  2. Obtain blood cultures.
  3. Administer broad-spectrum antibiotics.
  4. Begin rapidly administering crystalloid as per your organisation's policy.
  5. Apply vasopressors if hypotensive during or after fluid resuscitation to maintain a mean arterial pressure ≥ 65 mm Hg.
    • Vasopressors must be administered by a medical practitioner. The administration of this medicine should be considered in a critical care environment, however, if the patient is hypotensive, the objective is to maintain perfusion to all vital organs. Therefore, continuous blood pressure monitoring is imperative. The frequency of observation should be increased.

(SCCM 2019)

Sepsis and septic shock are medical emergencies. It is imperative that you act quickly and minimise the amount of time spent before commencing treatment. You must perform a thorough head-to-toe assessment and investigate any obvious signs of infection, increasing the frequency of observations and assessing if the patient is responding to the treatment (e.g. fluid resuscitation). You must inform colleagues about the patient’s status during handovers (SCCM 2019).

You should be able to locate the Surviving Sepsis Campaign’s guidelines at any time, along with your organisation’s own policies and protocols.

sepsis blood culture
'Blood Culture Tubes' by James Heilman, MD is licensed under CC BY-SA 3.0


The Hour-1 Bundle should be ideally commenced as soon as possible. Sepsis is an emergency and becomes more life-threatening the longer it’s left untreated. Immediate intervention after sepsis has been identified is crucial (SCCM 2019; Torborg 2018).

Untreated sepsis can cause the patient’s blood pressure to drop dramatically, causing it to progress into septic shock. The organs are starved of adequate blood supply, resulting in hypoperfusion and leading to multiple organ dysfunction syndrome. This is an extremely severe condition that can lead to fatality (Healthdirect 2022).

In sepsis, hypotension is caused by nitrous oxide production that increases after activation of the endothelium by pro-inflammatory mediators, responsible for vasodilation (Winkler et al. 2017).

If the early signs of sepsis have not been identified, the patient can deteriorate rapidly, requiring basic life support. Call for assistance as per hospital protocol. Remember to act quickly to save lives.

Post-Sepsis Outcomes

Only about 70% of people diagnosed with sepsis will survive, and of those survivors, 50% will develop post-sepsis syndrome (Sepsis Alliance 2022). This can be caused by a variety of factors, including any resulting permanent disability from the sepsis and also the psychological effects of both the illness and their prolonged hospitalisation.

Symptoms of Post-Sepsis Syndrome

These may include:

  • Insomnia
  • Nightmares, vivid hallucinations and panic attacks
  • Disabling muscle and joint pains
  • Extreme fatigue
  • Poor concentration
  • Decreased cognitive functioning
  • Loss of self-esteem and self-belief.

(Sepsis Alliance 2021)

Following recovery from sepsis, healthcare professionals must ensure that the patient’s treatment takes a holistic approach. This is essential as the individual may be feeling not only the physical effects of being ill, but also the psychological and cognitive effects of experiencing sepsis and social isolation following a prolonged hospital stay.


Test Your Knowledge

Question 1 of 3

True or false: Sepsis can be caused by any infection.


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Sally Moyle View profile
Sally Moyle is a rehabilitation nurse educator with Epworth HealthCare. She has completed her masters of nursing (clinical nursing and teaching) and has experience in many nursing sectors including rehabilitation, orthopaedic, neurosurgery, emergency, aged care and general surgery. Sally is passionate about education in nursing in order to produce the best nurses possible.