Effect of early packed red blood cell transfusion on sepsis-associated acute kidney injury: A target trial emulation

To date, the effects of packed red blood cell (PRBC) transfusion on sepsis-associated acute kidney injury (SA-AKI) have not been reported in the literature. The objective of this study is to conduct a preliminary exploration of the association between these two factors using a target trial emulation (TTE) that allows for causal inference.

The present study utilized the Medical Information Mart for Intensive Care IV (MIMIC-IV) database, including adult sepsis patients who were admitted to the intensive care unit (ICU) for the first time between 2008 and 2022, with an ICU stay exceeding 24 h. All patients had hemoglobin levels ≤ 10 g/dL within 24 h of sepsis diagnosis. A clone-censor-weight (CCW) approach was employed for target trial emulation (TTE) to evaluate the effects of PRBC transfusion within 24 h of sepsis diagnosis on patient outcomes. The primary outcome was SA-AKI, whereas the secondary outcomes included 7-, 28-, and 90-day mortality. The primary outcome underwent competing risk analysis. The treatment effect was primarily evaluated through differences in SA-AKI risk and survival rate. The 95% confidence intervals (CIs) were calculated using the nonparametric bootstrap method with 1000 repetitions.

The present study included a total of 14,869 patients. PRBC transfusion was not significantly associated with the risk of SA-AKI (risk difference: 0.67%, 95% CI: -1.32 to 2.63). However, compared with non-PRBC transfusion, PRBC transfusion significantly enhanced 7-, 28-, and 90-day survival, with significant survival differences of 2.54% (95% CI: 1.68 to 3.46), 4.86% (95% CI: 3.64 to 6.14), and 4.52% (95% CI: 3.06 to 5.97), respectively. Sensitivity analyses produced consistent results.

In this study, early PRBC transfusion did not impact the risk of SA-AKI but provided potential benefits in reducing mortality, particularly among sepsis patients with hemoglobin levels ≤ 10 g/dL.