Some patients with preoperative anemia have better outcomes if they get iron infusions before surgery rather than standard red blood cell transfusions, according to a rigorous medical records study by Johns Hopkins researchers that covered tens of thousands of patients.

The findings, published in Anesthesia & Analgesia, contribute to mounting evidence that such iron infusions, which boost the production of a person’s own red blood cells, are better than relying on someone else’s blood.

“Anemia is incredibly common, especially in surgical patients, and until recently, the default treatment has been blood transfusions prior to the procedure,” says Steven Frank, professor of anesthesiology and critical care medicine. “However, our retrospective study showed a benefit of iron infusions over preoperative blood transfusions in decreasing morbidity and mortality, increasing hemoglobin, and decreasing the need for blood transfusions.”

Anemia is particularly concerning for patients undergoing surgery because there is almost always some blood loss during any procedure. While blood transfusions work, they also carry risks, including blood clots, hospital-acquired infections, allergic reactions and pulmonary complications. It can be difficult to find a donor match if a patient has certain antibodies or a condition such as sickle cell disease. As a result, physicians have long sought strategies to minimize the use of transfusions.

In the new study, the Johns Hopkins Medicine research team used data from the TriNetX Research Network database, a global network of health care organizations that pool de-identified patient information. The team’s analysis used such information gathered between 2003 and 2023 on 154,358 patients over 18 years old with a diagnosis of iron-deficient anemia prior to surgery.

The data were sorted into groups of patients who were treated with iron preoperatively but not with a blood transfusion and patients who received a preoperative blood transfusion but no iron infusion. These infusions happened several weeks before a scheduled surgical procedure. Researchers then compared postoperative complication rates, including respiratory problems, kidney issues, blood clots, infections and death rates.

The researchers found a 37% reduction in mortality and a 24% reduction in morbidity in patients who were treated with iron infusions compared with those treated with blood transfusions. This finding means that patients receiving iron infusions may recover more quickly and fully from their surgical procedures without any added complications that can arise from a blood transfusion.

The researchers say they hope the new study will encourage more widespread use of preoperative iron infusions in surgical patients. They also hope to examine if oral iron supplements deliver the same outcomes as infusions.