Impact of Preoperative Iron Deficiency on Blood Transfusion in Elective Cardiac Surgery

Abstract

Objective: To evaluate the incidence and consequences of preoperative iron deficiency in elective cardiac surgery.

Design: A prospective observational study.

Setting: The cardiac surgery unit of a university hospital, from November 2016 to February 2017.

Participants: All patients presenting for elective cardiac surgery during the study period, with the exclusion of noncardiac thoracic surgeries, surgeries of the descending aorta, endovascular procedures, and patients affected by an iron-metabolism disease.

Interventions: Transferrin saturation and serum ferritin levels were systematically assessed before surgery, and the care of patients was maintained as usual.

Measurements and main results: Routine analyses, clinical data, and the number of blood transfusions were recorded during the hospital stay. Among the 272 patients included, 31% had preoperative iron deficiency and 13% were anemic. Patients with iron deficiency had significantly lower hemoglobin levels throughout the hospital stay and received blood transfusions more frequently during surgical procedures (31% v 19%, p = 0.0361). Detailed analysis showed that patients with iron deficiency received more red blood cell units. There were no differences in postoperative bleeding, morbidity, or mortality.

Conclusions: Iron deficiency appears to be related to lower hemoglobin levels and more frequent transfusions in elective cardiac surgery. Assessing iron status preoperatively and correcting any iron deficiencies should be one of the numerous actions involved in patient blood management for such surgeries, with the aim of reducing morbidity associated with both anemia and transfusion.

Keywords: anemia; blood transfusion; cardiac surgery; cardiopulmonary bypass; iron deficiency.