Preoperative anemia significantly increases the risk of transfusion.

A study of 15,414 patients undergoing elective gastrointestinal cancer surgery revealed that preoperative anemia affects 55.5% of cases, with 58.3% of anemic patients also iron deficient. Preoperative anemia is linked to a nearly threefold increase in the risk of red blood cell transfusion and adversely impacts postoperative outcomes. Specifically, each 1 g/dl decrease in hemoglobin raises transfusion risk by 40%, highlighting the necessity for improved management of treatable anemia causes.