Prognostic value of combined platelet and fibrinogen levels on mortality in pediatric patients with sepsis

Background Sepsis causes high mortality in pediatric intensive care units (PICUs), often involving coagulation dysfunction. While platelets and fibrinogen are crucial, their combined prognostic value in pediatric sepsis remains unclear. We investigated their additive utility on in-PICU mortality.Methods This retrospective cohort study included 282 pediatric sepsis patients admitted to the Zhujiang Hospital PICU (June 2022–December 2024). Multivariable Cox regression evaluated biomarkers continuously and categorically based on admission levels: platelets (cutoff: 150×109/L) and fibrinogen (cutoff: 2 g/L). Patients formed four combined groups: high/high (HPHF), high/low, low/high, and low/low (LPLF) platelets/fibrinogen.Results Decreased platelet and fibrinogen levels independently increased mortality risk (HR: 1.89, 95% CI: 1.16–3.06; and HR: 1.55, 95% CI: 1.08–2.24 per standard deviation). Categorically, low platelets (<150×109/L) and low fibrinogen (<2 g/L) independently predicted mortality (HR: 2.67, 95% CI: 1.29–5.51; HR: 1.98, 95% CI: 1.01–3.89). The LPLF group had significantly higher mortality than HPHF (HR: 4.05, 95% CI: 1.62–10.11). No significant interaction was observed. These associations were primarily significant in children ≥2 years.Conclusions Low platelet and fibrinogen levels at PICU admission independently predict mortality in pediatric sepsis. Their concurrent assessment provides additive prognostic value for early risk stratification, especially in children ≥2 years. Prospective multicenter validation is warranted.