By Daniel Diaz-Gil, MD· April 2026 · 18 min read
Pediatric sepsis remains a leading cause of morbidity and mortality worldwide. In 2024, the Society of Critical Care Medicine (SCCM) Pediatric Sepsis Definition Task Force published the Phoenix criteria, replacing the 2005 International Pediatric Sepsis Consensus Conference (IPSCC) criteria that relied on systemic inflammatory response syndrome (SIRS).
The IPSCC criteria used SIRS-based definitions that had poor predictive properties for identifying children at risk of death or serious morbidity. SIRS criteria captured many febrile children with benign viral illnesses while potentially missing children with "quiet" sepsis who had poor perfusion without meeting inflammatory criteria. The Phoenix criteria address this limitation by focusing on objective organ dysfunction rather than inflammation alone.
The Society of Critical Care Medicine recommends that sepsis in children be identified by a Phoenix Sepsis Score of at least 2 points in children with suspected infection, which indicates potentially life-threatening dysfunction of the respiratory, cardiovascular, coagulation, and/or neurological systems. Children with a Phoenix Sepsis Score ≥2 had in-hospital mortality of 7.1% in higher-resource settings and 28.5% in lower-resource settings, more than 8 times that of children with suspected infection not meeting these criteria.
Septic shock is defined as children with sepsis who have cardiovascular dysfunction, indicated by at least 1 cardiovascular point in the Phoenix Sepsis Score, which includes severe hypotension for age, blood lactate exceeding 5 mmol/L, or need for vasoactive medication. Children with septic shock had in-hospital mortality rates of 10.8% and 33.5% in higher- and lower-resource settings, respectively.
Use the Phoenix Sepsis Score calculator to score organ dysfunction at the bedside.
The Phoenix Sepsis Score evaluates four organ systems with the following point allocations:
Respiratory dysfunction (0-3 points): Based on PaO2/FiO2 ratio (or SpO2/FiO2 ratio) and respiratory support requirements. Invasive mechanical ventilation and impaired gas exchange contribute points.
Cardiovascular dysfunction (0-6 points): Assessed by age-adjusted severe hypotension, blood lactate >5 mmol/L, or need for vasoactive medications. This is the highest-weighted domain, reflecting the critical importance of hemodynamic instability.
Coagulation dysfunction (0-2 points): Based on platelet count, INR, fibrinogen, and D-dimer. Coagulopathy reflects consumptive processes and endothelial dysfunction.
Neurologic dysfunction (0-2 points): Assessed by Glasgow Coma Scale and pupillary reaction. Altered mental status indicates central nervous system compromise.
The organ-specific subscores sum to the total Phoenix Sepsis Score (maximum 13 points). Higher scores indicate worse organ dysfunction and worse prognosis. Notably, renal and hepatic dysfunction are not scored components of the core Phoenix criteria, though an expanded Phoenix-8 Score including these systems is available for research purposes.
The Phoenix criteria demonstrated superior performance compared to IPSCC criteria across diverse settings:
A 2026 multicenter European validation study confirmed that Phoenix criteria showed higher predictive performance than IPSCC criteria, with sensitivity of 96.4% and PPV of 7.6% on day 1 of PICU admission.
Important distinction: the Phoenix criteria are intended for diagnosis, benchmarking, quality improvement, and research. They are not designed as screening tools or to guide treatment decisions. Separate early recognition tools for screening are under development.
The pSOFA score adapts the adult SOFA score for pediatric use, evaluating six organ systems: respiratory (PaO2/FiO2), coagulation (platelets), hepatic (bilirubin), cardiovascular (mean arterial pressure and vasopressor requirements), neurologic (GCS), and renal (creatinine). Each domain is scored 0-4, yielding a total score of 0-24.
The Phoenix Sepsis Score was derived in part from pSOFA subscores, with some levels collapsed when performance was unaffected (e.g., pSOFA respiratory subscores of 1 and 2 points were collapsed into a single level). The Phoenix Score prioritizes simplicity and lower dependence on laboratory measures while maintaining predictive performance.
Use the pSOFA Score for serial assessment at the bedside.
The VIS quantifies the degree of cardiovascular support required:
VIS = dopamine (mcg/kg/min) + dobutamine (mcg/kg/min) + [100 × epinephrine (mcg/kg/min)] + [100 × norepinephrine (mcg/kg/min)] + [10 × milrinone (mcg/kg/min)] + [10,000 × vasopressin (U/kg/min)]
Higher VIS indicates greater medication burden and more severe circulatory instability. VIS has been validated in pediatric sepsis, with VIS at 48 hours showing the strongest correlation with ICU length of stay (r=0.53) and ventilator days (r=0.52). For every unit increase in VIS at 48 hours, there was a 13% increase in ICU length of stay and 8% increase in ventilator days.
Use the VIS Score to track vasopressor requirements.
A 2022 study identified four distinct VIS trajectory patterns in critically ill children with shock:
The "mild, fast resolving" and "severe, prolonged" groups were identifiable within the first 24 hours, while the two moderate groups were indistinguishable early but diverged in outcomes. Trending VIS provides critical clinical information: rising VIS indicates clinical deterioration despite treatment, while falling VIS suggests therapeutic response.
PEWS systems are designed to identify deteriorating children before they develop sepsis or require ICU transfer. The Bedside Paediatric Early Warning System (BedsidePEWS) is a validated 7-item score (range 0-26) that quantifies severity of illness in hospitalized children.
In a multicenter randomized trial (EPOCH), BedsidePEWS implementation was evaluated across 21 hospitals. PEWS scores increase over the 24 hours preceding urgent PICU admission, providing early warning of deterioration. At a score of 8, sensitivity was 82% and specificity was 93% for identifying children requiring urgent ICU admission.
A 2026 comparative study found that the Parshuram (BedsidePEWS) model demonstrated the highest diagnostic accuracy among four PEWS models evaluated, with AUC of 0.816 for ICU admissions at a threshold score ≥8.
Use the PEWS Calculator for bedside scoring.
The 2025 AHA/AAP Pediatric Advanced Life Support guidelines provide updated recommendations for fluid resuscitation in pediatric septic shock:
Evidence now supports judicious fluid resuscitation with frequent reassessment rather than aggressive volume loading. Two randomized trials showed that patients receiving higher fluid volumes or faster fluid resuscitation were more likely to develop clinically significant fluid overload with increased rates of mechanical ventilation and worsening oxygenation.
Blood lactate provides a valuable indirect marker of tissue hypoperfusion. Key thresholds:
Normalization of lactate within 2-4 hours of presentation is associated with decreased risk of persistent organ dysfunction (adjusted RR 0.47). The Surviving Sepsis Campaign suggests using trends in blood lactate levels, in addition to clinical assessment, to guide resuscitation.
For fluid-refractory septic shock, current guidelines recommend:
Fever alone is not sufficient for sepsis diagnosis. However, the following combinations warrant urgent evaluation:
When sepsis is suspected:
Reassess Phoenix Sepsis Score and/or pSOFA every 4-6 hours. Improving scores indicate effective treatment; stagnant or worsening scores necessitate treatment intensification and reassessment of diagnosis.
Lactate clearance is a real-time marker of perfusion adequacy. A decline >10-15% per hour represents appropriate response. Stagnant or rising lactate despite aggressive resuscitation suggests inadequate source control, resistant infection, or insufficient resuscitation.
VIS trending provides additional prognostic information. Rising VIS indicates clinical deterioration; falling VIS suggests therapeutic response. If vasopressor requirements escalate and VIS remains elevated after 4-6 hours of aggressive management, consider occult source of infection, inadequate source control, or resistant organisms.
The sepsis bundle components, early recognition, antibiotics, fluid resuscitation, vasopressor support, and source control, are interdependent and time-critical. Phoenix and pSOFA scores function as a clinical dashboard, monitoring whether interventions are achieving the desired physiologic response.