Red Blood Cell Transfusion Beyond Restrictive Thresholds in Patients With Septic Shock and an Elevated Lactate Level: A Multicenter Observational Study

Abstract

Background: Few studies have examined real-world transfusion practices in patients with septic shock. It is unclear whether red blood cell (RBC) transfusion benefits patients with an elevated lactate level. This study investigated transfusion practices and explored lactate as a physiological marker for guiding transfusion decisions. Methods: This observational study used data from a prospective, multicenter registry of patients with septic shock, provided by the Korean Shock Society, from November 2015 to December 2022. The initial hemoglobin (Hb) value and RBC transfusion status within six hours of emergency department visits were recorded. The in-hospital mortality rate was assessed based on the Hb level. The association between RBC transfusion and in-hospital mortality was analyzed using multivariable logistic regression, stratified by Hb groups and lactate level subgroups. Results: Among the 8,711 patients included, 884 (10.1%) received an RBC transfusion. Of these, 510 patients (57.7%) received a transfusion at an Hb level >= 7 g/dL. In the Hb 7.0-8.9 g/dL and Hb >= 9.0 g/dL groups, the transfusion group had a higher heart rate and a greater percentage of patients meeting the Sepsis-3 criteria for shock compared to the non-transfusion group. The initial lactate level was significantly higher in the transfusion group compared to the non-transfusion group in the Hb >= 9.0 g/dL group (median 5.3 mmol/L vs. 3.5 mmol/L). No significant association was found between RBC transfusion and in-hospital mortality in the Hb < 7.0 g/dL group (adjusted odds ratio [aOR], 0.86; 95% confidence interval [CI], 0.54-1.37) and the Hb 7.0-8.9 g/dL group (aOR, 0.79; 95% CI, 0.59-1.06). However, in the Hb >= 9.0 g/dL group, RBC transfusion was associated with an increased in-hospital mortality rate (aOR, 1.99; 95% CI, 1.34-2.93). The benefits of transfusion were not confirmed by the analysis based on the lactate level. Conclusion: RBC transfusions were frequently administered beyond restrictive thresholds in patients with septic shock, particularly in those with an elevated lactate level. However, RBC transfusion in patients with an elevated lactate level was not associated with decreased in-hospital mortality.