Effects of Blood Purification as an Adjunctive Treatment in Pediatric Septic Shock.

INTRODUCTION: Septic shock remains a major cause of early mortality in pediatric intensive care units. Blood purification (BP) has been used as an adjunctive therapy to modulate hyperinflammation, but pediatric evidence, particularly regarding optimal timing, remains limited. This study aimed to compare outcomes between standard treatment and adjunctive BP in children with persistent vasoactive-dependent septic shock and to identify factors associated with early survival. METHODS: We performed a retrospective-prospective observational cohort study of children aged 1 month to 18 years admitted to the PICU between January 2020 and December 2024 with vasoactive-inotropic score (VIS) ≥20 for >6 hours. The BP group received HA330® hemoadsorption based on intensivist discretion, while the control group received standard care. The primary outcome was 72-hour survival after the diagnosis of persistent vasoactive-dependent septic shock. Secondary outcomes included severity score changes, ventilator-free days, and 30-day mortality. RESULTS: Fifty-seven patients were included (BP n=12; control n=45). The BP group had greater baseline severity. Overall, 72-hour survival did not differ between groups. However, BP initiation at lactate <8 mmol/L was associated with significantly improved 72-hour survival (87.5 vs. 0%; p=0.04). Early initiation within 12 hours and PELOD-2 <12 showed trends toward improved survival (50 vs. 0%; p=0.08, and 75 vs. 0%; p=0.06, respectively). Among survivors, VIS decreased significantly after BP therapy from 72.5 [IQR 48, 138.8] to 50 [IQR 24.8, 85] at 6 hours and 30 [IQR 19.3, 51.3] at 24 hours (p=0.02). CONCLUSION: Blood purification was frequently used in more severely ill children and was not associated with improved survival overall. However, early initiation, particularly before marked lactate elevation and severe organ dysfunction, may improve early survival. These findings highlight timing as a key determinant of BP effectiveness in children with persistent vasoactive-dependent septic shock.