Platelet Count Trajectory and Survival in Children With Sepsis: Single-Center Retrospective Study in China, 2015–2023

OBJECTIVES: In children with sepsis, thrombocytopenia is linked to poor outcomes, including longer hospital length of stay, increased bleeding risk, and higher mortality. However, the clinical significance of changes in platelet counts over time remain poorly characterized. We have examined dynamic platelet patterns and their association with mortality and patient-illness factors. DESIGN: Single-center retrospective cohort study. SETTING: Hospital pediatrics and PICU at Guangdong Women and Children Hospital, China. PATIENTS: Children with sepsis between January 2015 and December 2023. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Group-based trajectory analysis was used to examine the trend in platelet count during the first 7 days of hospital admission. A regression model was developed to investigate possible associations between patient characteristics with platelet count trajectory. Additionally, a multivariable Cox proportional hazards model, adjusted for age, sex, comorbidities, and site/source of infection, was constructed to evaluate the association between platelet count trajectories and 28-day mortality. Among 1010 children with sepsis, we identified three platelet count trajectories with distinct characteristics. Age, fibrinogen level, activated partial thromboplastin time, and lactic acid were each associated with platelet count trajectories. The overall 28-day mortality for the cohort was 5.4%, varying across groups: 1.2% in group 3 with persistently high platelet count; 2.2% in group 2 with high-normal platelet count; and 12.6% in group 1 with low platelet count. In the multivariable Cox proportional hazards model, compared with group 1, both groups 2 and 3 were independently associated with reduced hazard of death at 28 days (hazard ratio, 0.26; p < 0.001 for group 2 and hazard ratio, 0.18; p = 0.021 for group 3). CONCLUSIONS: We have identified three distinct and clinically relevant platelet count trajectories in children with sepsis, which serve as robust associations with survival in this patient population.