Dynamic platelet profiles in the emergency department and their predictive value for 28-day all-cause mortality in septic patients

by Jianchun Wei, Xinjie Huang, Zhilian Wang, Hailing Zhang Background Sepsis is a significant cause of global mortality and most frequently first presents in the emergency department. Dynamic platelet changes play a key pathophysiological role in sepsis, yet their comprehensive prognostic value—particularly from a multi-dimensional perspective that includes value, magnitude, and timing—remains underexplored.

Methods In this retrospective cohort study, 363 episodes of sepsis first diagnosed in the emergency department of Beijing Aviation General Hospital between April 2020 and January 2025 were included. We systematically analyzed three dimensions of platelet counts: 1) nadir value; 2) the magnitude of platelet decline; 3) dynamic timing (time to nadir and maximum decline).

Multivariable Cox regression models were used to assess their independent associations with 28-day all-cause mortality, adjusting for demographics, comorbidities, infection characteristics, and disease severity. Results Among 363 patients (median age 81 years, 54.5% male), the 28-day mortality rate was 39.9%.

Compared to survivors, non-survivors had a lower platelet nadir [70.0 vs.