Response

Abstract

We thank Perel et al for their thoughtful reading of our study on early blood transfusions in sepsis.1 Perel et al correctly note that our analysis was at the hospital rather than the patient level and propose 2 additional analyses: a patient-level analysis examining the association of blood transfusions on the study outcomes and a patient-level subgroup analysis that excludes patients who received transfusions after day 2 of their hospitalization. These proposals are worthwhile extensions to our work provided that appropriate variables are used for multivariable adjustment, most notably a patient’s hemoglobin concentration over time. Unfortunately, hemoglobin data were absent from our database. Hence, we performed a hospital-level analysis, which mitigates some bias inherent in patient-level analyses.2A key finding of our study that would be lost in a patient-level analysis was the considerable variation in early transfusion rates at the hospital level after adjustment for many potential confounders, including chronic blood loss anemia, deficiency anemia, and the administration of supplemental iron (a treatment for anemia). Large variations in practice in the treatment of sepsis show the “knowledge gap” we currently face when treating this condition and the importance of sepsis guidelines for optimal care.3,4 Notably, we observed at the hospital level, a comparable group of sepsis patients received transfusions as frequently as 1 in every 10 patients or as rarely as 1 in every 25 patients without any differences in mortality rates but with increased costs.Also, in a recent study5 that examined red blood cell (RBC) transfusions and hematocrit evolution patterns in approximately 6000 sepsis patients at the patient level, researchers found no association with RBC transfusions and mortality (hazard ratio, 1.07; 95% CI, 0.88–1.30; P =.52). Results of that study support our findings. Moreover, a growing body of literature increasingly questions the efficacy of early goal-directed therapy for septic shock. This trend suggests a judicious approach to RBC transfusions in sepsis,6 especially in patients experiencing hemodilution as a result of receiving large volumes of crystalloid solution, which Perel et al explain well in their letter.