Phoenix Sepsis Criteria in Critically Ill Children: Retrospective Validation Using a United States Nine-Center Dataset, 2012-2018

Abstract

Objectives: To perform: 1) external validation of the Phoenix Sepsis Score and Phoenix sepsis criteria in a multicenter cohort of critically ill children with infection and a comparison with the 2005 International Pediatric Sepsis Consensus Conference (IPSCC) criteria; 2) a study of Phoenix sepsis criteria performance in patient subgroups based on age and comorbidities; 3) an assessment of microbiological profile of children with Phoenix sepsis; and 4) a study of the performance of the Phoenix-8 score.

Design: Secondary, retrospective analysis of a multicenter cohort study from 2012 to 2018.

Setting: Nine PICUs in the United States.

Patients: PICU admissions with suspected infection.

Interventions: None.

Measurements and main results: Among 25,680 encounters of children with suspected or confirmed infection on PICU admission (4.6% in-hospital mortality), 11,168 (43%) met Phoenix criteria for sepsis or septic shock (9% in-hospital mortality). The Phoenix criteria generally outperformed the IPSCC criteria at discriminating mortality in all critically ill children with infections and across all subgroup analyses, including age group, malignancy, or technology dependence. Of 11,168 patients who met Phoenix criteria, 28% were negative for IPSCC criteria for sepsis and these had higher in-hospital mortality than those who met IPSCC sepsis criteria but not Phoenix criteria (4.7% vs.1.7%; p < 0.001), which was similar to the mortality of patients without sepsis (1.3%). Sepsis was associated with respiratory or bloodstream infection, most commonly Pseudomonas aeruginosa or Staphylococcus aureus. The Phoenix-8 score had good discrimination of mortality in children with infections, comparable to or better than validated and widely used severity of illness and organ dysfunction scores.

Conclusions: In 2012-2018, among U.S. patients with suspected or confirmed infection admitted to nine PICUs, those with the highest risk of mortality can be identified using the Phoenix sepsis criteria, including in children of different age groups and those with major comorbidities.

Figure 1.

Distribution and associated in-hospital mortality across the Phoenix Sepsis Score in the first 24 hr of admission among critically ill children with confirmed or suspected infection. The vertical dashed line separates patients with and without sepsis based on the Phoenix criteria.

Figure 2.

Performance of sepsis criteria. Comparison of the sensitivity and positive predictive value (PPV) of the criteria for sepsis based on the Phoenix criteria vs. the 2005 International Pediatric Sepsis Consensus Conference (IPSCC) criteria to discriminate in-hospital mortality (A) and early death or extracorporeal membrane oxygenation (ECMO) (B); the comparison of the criteria for septic shock based on Phoenix criteria vs. IPSCC criteria to discriminate in-hospital mortality (C) and early death or ECMO (D). The baseline rate of the outcome in each group (in-hospital mortality or early death or ECMO) is shown as a horizontal dashed line. These figures are similar to the area under the precision-recall curve except at a single threshold for criteria that generate a binary response (e.g., yes/no sepsis criteria met) instead of across the entire range of possible points in the curve. Better performing criteria on these figures will be closer to the top right corner of the figure.