In-hospital stay of anemic patients (70-90 g.L-1) in the ED with/without transfusion: a single-center propensity-matched study.

Background and importance: A quarter of patients presenting to the emergency department (ED) have anemia. Although red blood cell (RBC) transfusion is routinely used in symptomatic anemia, there is no evidence on the benefit of blood transfusion in hemodynamically stable patients in the ED for patients requiring hospitalization. Objective: The study aimed to compare in-hospital length of stay (LOS) of patients with anemia between 70 and 90 g.L-1 transfused or not in ED. Design : Retrospective single-center study Settings and participants: All adult patients admitted to the ED of our university hospital with an initial hemoglobin level between 70 and 90 g.L-1, without hemorrhagic shock, who were hospitalized after ED admission. Outcome measures and analysis: A propensity score, comprising hemoglobin level, Charlsons comorbidity index, clinical signs of anemia, the chronicity of anemia and hospitalization department was used to compare the LOS of patients transfused versus non-transfused in the ED. Intervention: RBC transfusion in the ED Main results: From January 1st to December 31st, 2022, 1 169 patients were screened of whom 569 (49%) were excluded, mostly due to discharge without hospitalization. The remaining 564 (48%) patients had a median age of 77 [68; 85] and 240 (43%) were women. Finally, 127 (23%) patients were transfused in ED. Transfused patients received more units of RBC during the whole hospitalization period (4 [3; 5] versus 2 [1; 3] than non-transfused patients (p< 0.01)). After propensity score matching, median LOS was 9 [5; 19] days for ED transfused patients and 8 [5; 15] days for non-ED transfused patients (median difference= -1 95% CI [-3; 2]; p= 0.45). Conclusion: In patients with non-life-threatening anemia, RBC transfusion in the ED does not appear to reduce in-hospital LOS compared with transfusion in inpatient departments. Further studies are needed to identify patients requiring transfusion in ED.