Pediatric Sepsis Definition 2024

We are all aware of the potential severe impact that infections can have in pediatric patients. Infections are one of the most common topics in the PedEM Morsels (clearly a significant measure of their importance! ūüėú ) and we all know that the critically ill child must have potential infection and sepsis high on the list of possible etiologies. Sepsis is a term that gets iterated often in our Emergency Departments, whether we are caring for adults or children. While it may be a quick way to communicate the severity of illness, the word actually has meaning and, recently, the definition of “pediatric sepsis” was revised [Schlapbach, 2024]. While this revision will not necessarily help you to find the subtly sick child who has evolving sepsis, it will help us communicate more clearly with our colleagues. Let’s take a minute to digest a tasty morsel on the revised pediatric sepsis definition:

Pediatric Sepsis Definition: Background

  • Sepsis is the leading cause of death of children worldwide. [Schlapbach, 2024]
    • The risk of developing sepsis is highest in pediatric patients compared to all other age groups.
    • The risk is further accentuated in the lower-resource settings.
  • Sepsis in children is not identical to the in adults. [Schlapbach, 2024]
    • Children have age-specific variability of vital signs.
    • Immune function varies based on age as well.
    • Children have different comorbidities, epidemiology, and outcomes.
  • Similar to adults, the criteria that define sepsis has evolved, appropriately, as we learn more about sepsis, its management, and its impact. [Schlapbach, 2024]
    • In 2005, criteria described specific pediatric sepsis.
      • Like adult criteria, it included Systemic Inflammatory Response Syndrome (SIRS), Sepsis, Severe Sepsis, and Septic Shock.
      • SIRS criteria found to perform poorly in children.
    • In 2016, criteria for adult sepsis changed based on improved data.
      • It focused on presence of life-threatening organ dysfunction and used Sequential Organ Failure Assessment (SOFA) score.
      • This change was not reflected in the pediatric definition/critieria.
  • Pediatric Sepsis Definition / Criteria should: [Schlapbach, 2024]
    • Account for the pediatric specific variances.
    • Be applicable to pediatric patients globally, particularly in lower-resourced settings where the burden is greatest.
    • Be applicable to Emergency Departments and regular inpatient care settings (where 80% of pediatric sepsis is first identified).

Pediatric Sepsis Definition: The Criteria

The Phoenix Sepsis Score

Named for the mythical creature that rose from ashes… and also because the 2024 Society of Critical Care Medicine Congress met in Phoenix, Arizona. [Schlapbach, 2024]

  • Uses a composite 4-organ system model
    • Respiratory
    • Cardiovascular
    • Neurological
    • Coagulation Dysfunction
  • Sepsis and Life-threatening Organ Dysfunction in children with Suspected/Confirmed Infection can be identified as a Phoenix Score of at least 2 points.
    • Severe Sepsis” is a term that should NOT be used any longer.
      • Essentially, once you have defined organ dysfunction that mets Sepsis criteria, the illness is severe.
      • SIRS is also not used.
    • Septic Shock is a subset of Sepsis.
      • Have Cardiovascular Dysfunction and higher mortality.
      • Defined by a Cardiovascular score of at least 1 point.
Respiratory (0-3 points)
0 Points1 Point2 Points3 Points
PaO2:FiO2 > 400 or Sp02:Fi02 > 292 (only calculated if Sp02 </=97%)PaO2:FiO2 < 400 on any Respiratory Support or Sp02:Fi02 < 292 (on support)PaO2:FiO2 100 – 200 on Mechanical Ventilation or Sp02:Fi02 148-220 on IMVPaO2:FiO2 < 100 or Sp02:Fi02 <148
Cardiovascular (0-6 points)
0 Points1 Point2 Points
No Vasoactive Medication
Lactate < 5 mmol/L
1 Point each (up to 3)
1 Vasoactive Medication
Lactate 5-10.9 mmol/L
2 Points each (up to 6)
>/= 2 Vasoactive Medications
Lactate >/ 11 mmol/L
Aged-Based Mean Arterial Pressure (mmHg) (0-2 points)
AGE0 Points1 Point2 Points
< 1 month>30 mmHg17-30 mmHg< 17 mmHg
1-11 mos>38 mmHg25-38 mmHg< 25 mmHg
1 – < 2yrs>43 mmHg31-43 mmHg<31 mmHg
2 – <5 yrs>44 mmHg32-44 mmHg<32 mmHg
5 – < 12yrs>48 mmHg36-48 mmHg<36 mmHg
12 – 17 yrs>51 mmHg38-51 mmHg<38 mmHg
Coagulation (0-2 points)
0 Points1 Point
Platelets >/= 100×10^3
INR </= 1.3
D-Dimer </= 2 mg/L
Fibrinogen >/= 100 mg/dL
Platelets < 100×10^3
INR > 1.3
D-Dimer > 2 mg/L
Fibrinogen < 100 mg/dL
Neurological (0-2 points)
0 Points1 Point2 Points
GCS > 10;
Pupils Reactive
GCS </= 10Fixed Pupils
  • Unmeasured variables contribute no points to the score, but you do not need to account for every variable in order to meet the definition of Sepsis (only need 2 or more points).
  • This score applies to children younger than 18 years of age.
  • DOES NOT apply to children who are:
    • Newly born
    • Neonates who’s post-conceptional age is < 37 weeks.

Pediatric Sepsis Definition: Keep Perspective

  • The Phoenix Score can be applied AFTER you have determined that the patient has a Suspected or Confirmed Infection.
  • The Phoenix Sepsis Score is NOT intended to be used as an early screening tool to help recognize possible sepsis in children.
  • The Score correlates with in-hospital mortality!
    • Suspected infection => in-hospital mortality of 0.7% (higher-resource area) and 3.6% (lower-resource setting).
    • Phoenix Sepsis Score of at least 2 (ie, Sepsis) => in-hospital mortality of 7.1% (higher-resource area) and 28.5% (lower-resource setting).
  • The Phoenix Sepsis Score is aimed at:
    • Improving clinical care
    • Epidemiological assessment
    • Research on pediatric sepsis and septic shock globally

Moral of the Morsel

  • Let’s speak the same language. How we define things helps us all understand how to compare our research as well as our management and outcomes.
  • Organ Dysfunction sounds bad… because it is! Using the Phoenix Sepsis Score helps to focus the understanding of severity of illness based on the thing we care about… organ dysfunction.
  • 2 is too many! A Phoenix Sepsis Score of 2 or more has real implications on mortality!


Schlapbach LJ, Watson RS, Sorce LR, Argent AC, Menon K, Hall MW, Akech S, Albers DJ, Alpern ER, Balamuth F, Bembea M, Biban P, Carrol ED, Chiotos K, Chisti MJ, DeWitt PE, Evans I, Flauzino de Oliveira C, Horvat CM, Inwald D, Ishimine P, Jaramillo-Bustamante JC, Levin M, Lodha R, Martin B, Nadel S, Nakagawa S, Peters MJ, Randolph AG, Ranjit S, Rebull MN, Russell S, Scott HF, de Souza DC, Tissieres P, Weiss SL, Wiens MO, Wynn JL, Kissoon N, Zimmerman JJ, Sanchez-Pinto LN, Bennett TD; Society of Critical Care Medicine Pediatric Sepsis Definition Task Force. International Consensus Criteria for Pediatric Sepsis and Septic Shock. JAMA. 2024 Feb 27;331(8):665-674. doi: 10.1001/jama.2024.0179. PMID: 38245889; PMCID: PMC10900966.

Sean M. Fox
Sean M. Fox

I enjoy taking care of patients and I finding it endlessly rewarding to help train others to do the same. I trained at the Combined Emergency Medicine and Pediatrics residency program at University of Maryland, where I had the tremendous fortune of learning from world renowned educators and clinicians. Now I have the unbelievable honor of working with an unbelievably gifted group of practitioners at Carolinas Medical Center. I strive every day to inspire my residents as much as they inspire me.

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