Assessment of Phoenix Sepsis Score, pSOFA, PELOD-2, and PRISM III in Pediatric Intensive Care

<b>Background/Objectives</b>: Early identification of pediatric sepsis complications in intensive care is challenging and requires improved diagnostic tools. This study aimed to compare the Phoenix Sepsis Score (PSS), pSOFA, PELOD-2, and PRISM III in assessing clinical complexity in children with septic and critical conditions in the PICU and to identify the most suitable scale for this patient cohort. <b>Methods</b>: Data were collected prospectively from 53 children between June 2022 and January 2024. Patients were categorized into septic (n = 42) and non-infectious SIRS (n = 11) and further classified by outcome-with/without complications (n = 23/30). The predictive accuracy of the scoring systems was evaluated by discrimination and calibration and by recalibration for the PSS for improved performance. <b>Results</b>: Respiratory (18.8%) and neurological complications (9.4%) were the most common adverse events. Clinical deterioration was observed in 43.4% of cases, including one fatality. Patients with complications stayed longer in the PICU (14 ± 10 days). In the patients with complications, all scoring systems had higher median values. Only PSS showed a significant difference (<i>p</i> = 0.0023). PSS demonstrated the highest overall predictive accuracy (76.2%) outperforming PRISM III (62.3%) and PELOD-2 (58.5%). The pSOFA scale showed high accuracy (88.0%) in identifying patients without complications. The strongest association was between chronic disease (hazard ratio Exp(B) = 1.718) and deteriorations, while mechanical ventilation suggested a reduced risk of complications (Exp(B) = 0.509). <b>Conclusions</b>: PSS showed superior predictive accuracy (76.2%) for deteriorations in pediatric patients with suspected infection and proved adaptable for further validation in larger populations.