Comparison of restrictive and liberal transfusion strategies on clinical outcomes in patients with upper gastrointestinal bleeding in the emergency department

absolute indications [12,15].Therefore, within the framework of patient blood management (PBM), the primary goals include prevention of anemia, preservation of red cell mass, maintenance of hemostasis, and avoidance of unnecessary transfusions [16][17][18].The World Health Organization defines anemia as a hemoglobin (Hb) level < 13 g/dL in men, < 12 g/dL in women, and < 11 g/dL in pregnant women [19].However, in clinically stable patients, a transfusion threshold of 7 g/ dL is commonly recommended and supported by multiple clinical guidelines [20][21][22][23].Adverse effects associated with transfusion include hemolytic reactions, alloimmunization, infection risk, immunomodulation, and increased mortality, highlighting the importance of careful decision-making [13-15, 18, 24].Currently, the use of blood components such as packed red blood cells, fresh frozen plasma, and platelets instead of whole blood aims to improve transfusion safety [18].In patients with UGI bleeding, transfusion strategies are generally categorized into two main approaches: restrictive and liberal.The restrictive strategy typically recommends transfusion when Hb levels fall below 7 g/dL, whereas the liberal strategy advocates initiating transfusion at Hb levels of 9-10 g/dL [20, 21,23].In a multicenter randomized controlled trial conducted by Villanueva et al., the restrictive strategy was reported to be superior to the liberal approach in terms of mortality, rebleeding rates, and complications [25,26].Similarly, Cochrane reviews and observational studies have demonstrated that restrictive transfusion strategies are at least as safe as liberal strategies and may even be more advantageous in certain clinical scenarios [23,24,26,27].Conversely, some evidence suggests that liberal transfusion, particularly in variceal bleeding associated with portal hypertension, may increase portal pressure and consequently elevate the risk of rebleeding [12,28,29].Feasibility studies such as TRIGGER have shown that liberal transfusion