An age-adjusted version of the Sequential Organ Failure Assessment score for sepsis has been found to be at least as good, if not better than, other pediatric organ dysfunction scores at predicting in-hospital mortality.
Writing in the Aug. 7 online edition of JAMA Pediatrics, researchers reported the outcome of a retrospective observational cohort study in 6,303 critically ill patients aged 21 years or younger, which was used to adapt and validate a pediatric version of the Sequential Organ Failure Assessment (SOFA) score.
“One of the major limitations of the SOFA score is that it was developed for adult patients and contains measures that vary significantly with age, which makes it unsuitable for children,” wrote Travis J. Matics, DO, and L. Nelson Sanchez-Pinto, MD, of the department of pediatrics at the University of Chicago.
Several pediatric organ dysfunction scores exist, but their range, scale, and coverage are different from those of the SOFA score, which makes them difficult to use concurrently (JAMA Pediatr. 2017 Aug 7. doi: 10.1001/jamapediatrics.2017.2352).
“Fundamentally, having different definitions of sepsis for patients above or below the pediatric-adult threshold has no known physiologic justification and should therefore be avoided,” the authors wrote.
In this study, they modified the age-dependent cardiovascular and renal variables of the adult SOFA score by using validated cut-offs from the updated Pediatric Logistic Organ Dysfunction (PELOD-2) scoring system. They also expanded the respiratory subscore to incorporate the SpO2:FiO2 ratio as an alternative surrogate of lung injury.
The neurologic subscore, based on the Glasgow Coma Scale, was changed to a pediatric version of the scale. The coagulation and hepatic criteria remained the same as the adult version of the score.
Validating the pediatric version of the SOFA score (pSOFA) score in 8,711 hospital encounters, researchers found that nonsurvivors had a significantly higher median maximum pSOFA score, compared with survivors (13 vs. 2, P less than .001). The area under the curve (AUC) for discriminating in-hospital mortality was 0.94 (95% confidence interval, 0.92-0.95) and remained stable across sex, age groups, and admission types.
The maximum pSOFA score was as good as the PELOD and PELOD-2 scales at discriminating in-hospital mortality and better than the Pediatric Multiple Organ Dysfunction Score. It also showed “excellent” discrimination of in-hospital mortality among the 48.4% of patients who had a confirmed or suspected infection in the pediatric intensive care unit (AUC, 0.92; 95% CI, 0.91-0.94), Dr. Matics and Dr. Sanchez-Pinto reported.
Researchers also looked at the clinical utility of pSOFA on the day of admission, compared with the Pediatric Risk of Mortality (PRISM) III score, and found the two were similar, while the pSOFA outperformed other organ dysfunction scores in this setting.
Overall, 14.1% of the pediatric intensive care population met the sepsis criteria according to the adapted definitions and pSOFA scores, and this group had a mortality of 12.1%. Four percent of the population met the criteria for septic shock, with a mortality of 32.3%.
The SOFA score incorporates respiratory, coagulation, renal, hepatic, cardiovascular, and neurologic variables. The authors, however, argued that it does not account for age-related variability, in particular in renal criteria and the detrimental effects of kidney dysfunction in younger patients.
“In addition, the respiratory subscore criteria – based on the ratio of PaO2 to the fraction of inspired oxygen (FiO2) – have not been modified in previous adaptations of the SOFA score even though the decreased use of arterial blood gases in children is a known limitation,” they wrote.
“Having a harmonized definition of sepsis across age groups while recognizing the importance of the age-based variation of its measures can have many benefits, including better design of clinical trials, improved accuracy of reported outcomes, and better translation of the research and clinical strategies in the management of sepsis,” Dr. Matics and Dr. Sanchez-Pinto said.
They acknowledged, however, that their findings were limited because they were generated using retrospective data and needed to be validated in a large multicenter sample of critically ill children. They also pointed out that they did not evaluate the performance of pSOFA as a longitudinal biomarker and suggested that such studies would improve understanding of pSOFA’s clinical utility.
No conflicts of interest were reported.