Pediatric Sepsis Criteria Calculator

Pediatric Sepsis Criteria Calculator for Pediatrics. A total score below 2 in a child with suspected infection does not meet Phoenix sepsis criteria; a score of 2 or higher defines sepsis and signals potentially life-threatening dysfunction of the respiratory, cardiovascular, coagulation, or neurological systems. In the validation cohorts, children meeting the 2-point threshold had in-hospital mortality of roughly 7% in higher-resource settings and about 28% in lower-resource settings, more than eight times that of infected children below the threshold. Any cardiovascular point on top of sepsis defines septic shock, associated with mortality near 11% and 34% in higher- and lower-resource settings respectively. Meeting criteria should trigger prompt escalation: senior review, sepsis-bundle care, and close monitoring, with a higher score reflecting more organ systems failing.

How this calculator works

These are the 2024 Phoenix sepsis criteria, built on the Phoenix Sepsis Score, which sums points across four organ systems: respiratory (0-3, driven by PaO2/FiO2 or SpO2/FiO2 ratio and level of respiratory support), cardiovascular (0-6, from number of vasoactive agents, lactate, and age-adjusted mean arterial pressure), coagulation (0-2, from platelets, INR, D-dimer, and fibrinogen, capped at 2), and neurological (0-2, from Glasgow Coma Scale and pupil reactivity). The total ranges 0-13. In a child under 18 years with suspected or confirmed infection, sepsis is defined as a score of at least 2, and septic shock as sepsis plus at least 1 cardiovascular point. The score was derived from stacked regression models predicting in-hospital mortality across more than 3 million pediatric encounters at 10 sites on 4 continents.

When to use this calculator

Apply this to children younger than 18 years in the emergency department or hospital who have suspected or confirmed infection, to identify life-threatening organ dysfunction and flag septic shock. It replaces the 2005 IPSCC/SIRS-based definitions and deliberately drops the term "severe sepsis." It is not a screening tool for undifferentiated fever and is not validated in neonates around the time of birth (the derivation excluded gestational age under 37 weeks in the first week of life) or for preterm infants; it also assumes infection is already suspected, so it does not by itself decide whether to start antibiotics.

Inputs used

  • Age
  • Temperature
  • Heart rate
  • Respiratory rate
  • Blood pressure
  • Perfusion
  • Mental status
  • Laboratory or organ dysfunction markers

Clinical interpretation

A total score below 2 in a child with suspected infection does not meet Phoenix sepsis criteria; a score of 2 or higher defines sepsis and signals potentially life-threatening dysfunction of the respiratory, cardiovascular, coagulation, or neurological systems. In the validation cohorts, children meeting the 2-point threshold had in-hospital mortality of roughly 7% in higher-resource settings and about 28% in lower-resource settings, more than eight times that of infected children below the threshold. Any cardiovascular point on top of sepsis defines septic shock, associated with mortality near 11% and 34% in higher- and lower-resource settings respectively. Meeting criteria should trigger prompt escalation: senior review, sepsis-bundle care, and close monitoring, with a higher score reflecting more organ systems failing.

Worked example

A 4-year-old with pneumonia has SpO2/FiO2 supporting 2 respiratory points, is receiving one vasoactive infusion with a lactate of 4 mmol/L for 2 cardiovascular points, has a platelet count of 90 x10^9/L for 1 coagulation point, and a GCS of 10 for 1 neurological point. Total Phoenix Sepsis Score = 6. Because the score is at least 2, the child meets criteria for sepsis; because there is at least 1 cardiovascular point, the child also meets criteria for septic shock, placing them in the group with markedly elevated in-hospital mortality.

Limitations and safety notes

The score was derived retrospectively from electronic health record data on children with suspected infection, so it presumes clinical suspicion has already been raised and will not catch occult infection. Performance was strong for mortality discrimination but the area under the precision-recall curve was modest (roughly 0.23-0.38), reflecting the low base rate of death, so a low score does not rule out deterioration. It is not validated for neonates in the immediate postnatal period or for premature infants, and requires labs such as lactate, platelets, and coagulation studies that may be unavailable in the most resource-limited settings where a fluid-refractory shock definition may still be needed.

Frequently asked questions

How is this different from the old 2005 pediatric sepsis criteria?

The 2005 IPSCC criteria were built on SIRS (temperature, heart rate, respiratory rate, white cell count), which flags common febrile illness and predicts mortality poorly. The Phoenix criteria instead require demonstrable organ dysfunction across four systems and were data-driven against in-hospital mortality. The term 'severe sepsis' has also been abandoned; sepsis now inherently means infection plus organ dysfunction.

What score defines sepsis versus septic shock?

In a child with suspected infection, a Phoenix Sepsis Score of at least 2 defines sepsis. Septic shock is sepsis plus at least 1 cardiovascular point, which can come from age-adjusted hypotension, lactate above 5 mmol/L, or the need for vasoactive medication.

Which organ systems and variables feed the score?

Four systems: respiratory (oxygenation ratio and support level, 0-3), cardiovascular (vasoactive agents, lactate, age-adjusted MAP, 0-6), coagulation (platelets, INR, D-dimer, fibrinogen, capped at 2), and neurological (GCS and pupils, 0-2). Two additional systems (renal, hepatic) were studied in an expanded 'Phoenix-8' model but are not part of the core criteria.

Can I use it in newborns?

No. The derivation and validation excluded neonates in the first week of life at term-equivalent age and did not cover preterm infants, so the criteria are not validated for the perinatal period. Neonatal sepsis remains a separate clinical problem.

Does a Phoenix score of 0 or 1 rule out serious illness?

No. A score below 2 does not meet sepsis criteria but does not exclude a child who may still deteriorate, especially early in an illness before organ dysfunction is measurable. Continued reassessment and clinical judgment remain essential.

References

  • Schlapbach LJ, Watson RS, Sorce LR, et al; Society of Critical Care Medicine Pediatric Sepsis Definition Task Force. International Consensus Criteria for Pediatric Sepsis and Septic Shock. JAMA. 2024;331(8):665-674. PMID: 38245889.
  • Sanchez-Pinto LN, Bennett TD, DeWitt PE, et al. Development and Validation of the Phoenix Criteria for Pediatric Sepsis and Septic Shock. JAMA. 2024;331(8):675-686. PMID: 38245897.

Editorial review and citation methodology

Reviewed by the Quick Medical Calculator Editorial Team. Last reviewed: June 27, 2026. The review checks calculator inputs, intended population, interpretation, limitations, and source alignment.

  • Prefer original validation studies for scoring systems and prediction tools.
  • Use current specialty society guidance, transplant allocation policy, public health guidance, or regulator resources when they govern clinical use.
  • Include limitations and safety notes when a calculator is population-specific, context-dependent, or unsuitable as a standalone decision tool.

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