Association of pretransfusion platelet count with mortality in patients with sepsis-associated acute kidney injury

This retrospective cohort study evaluated the association between pretransfusion platelet count and outcomes in adults receiving platelets after sepsis-associated acute kidney injury (SA-AKI), using data from the Medical Information Mart for Intensive Care IV. The exposure was the minimum platelet count during the 48 h before the first eligible transfusion. The primary cohort included 1047 patients with counts ≤ 100 × 10 9 /L. Follow-up began at transfusion. Multivariable Cox regression and restricted cubic splines (RCS) were used to assess associations with 28-day (primary) and 90-day all-cause mortality. Each 10 × 10 9 /L increase in platelet count was associated with lower 28-day mortality (adjusted hazard ratio [HR] 0.915; 95% confidence interval [CI] 0.864–0.970) and 90-day mortality (HR 0.915; 95% CI 0.868–0.964). RCS analysis in the primary cohort showed no clear evidence of nonlinearity. No statistically significant association was detected with post-transfusion intensive care unit length of stay. Among adults receiving platelets after SA-AKI onset with pretransfusion platelet counts ≤ 100 × 10 9 /L, higher counts were associated with lower 28- and 90-day mortality. These findings support further evaluation of pretransfusion platelet count as a prognostic marker in this population.