Performance of prognostic markers in pediatric sepsis

Objective: To evaluate the prognostic performance of the Pediatric Index of Mortality 2 (PIM2), ferritin, lactate, C-reactive protein (CRP), and leukocytes, alone and in combination, in pediatric patients with sepsis admitted to the pediatric intensive care unit (PICU).

Methods: A retrospective study was conducted in a PICU in Brazil. All patients aged 6 months to 18 years admitted with a diagnosis of sepsis were eligible for inclusion. Those with ferritin and C-reactive protein measured within 48h and lactate and leukocytes within 24h of admission were included in the prognostic performance analysis.

Results: Of 350 eligible patients with sepsis, 294 had undergone all measurements required for analysis and were included in the study. PIM2, ferritin, lactate, and CRP had good discriminatory power for mortality, with PIM2 and ferritin being superior to CRP. The cutoff values for PIM2 (> 14%), ferritin (> 135ng/mL), lactate (> 1.7mmol/L), and CRP (> 6.7mg/mL) were associated with mortality. The combination of ferritin, lactate, and CRP had a positive predictive value of 43% for mortality, similar to that of PIM2 alone (38.6%). The combined use of the three biomarkers plus PIM2 increased the positive predictive value to 76% and accuracy to 0.945.

Conclusions: PIM2, ferritin, lactate, and CRP alone showed good prognostic performance for mortality in pediatric patients older than 6 months with sepsis. When combined, they were able to predict death in three-fourths of the patients with sepsis. Total leukocyte count was not useful as a prognostic marker.