Patient Blood Management In CARdiac sUrgical patientS

Overview

Nowadays up to 40% of patients undergoing cardiac surgery receives at least 1 unit of red blood cell transfusion during surgery or during the first week after surgery. Moreover up to 40% of these patients shows an absolute or relative iron deficiency, with or without anaemia. The objective of this study is to assess whether to implement an adequate correction of iron according to current "patients blood management" recommendations might reduce RBC transfusion requirements in patients undergoing heart surgery. Data obtained in patients included in the study will be compared to those of a case-control population selected from patients consecutively treated at the same department in the previous 2 years.

Anemia is defined by the World Health Organization (WHO) as a value of hemoglobin (Hb) \< 130 g/L in men and \< 120 g/L in women. Anemia in surgical patients is a common and serious problem, in fact up to 40% of patients presenting for major surgery are anemic. Patients with pre-operative anemia have significantly higher rates of morbidity and mortality and are likely to receive red blood cell (RBC) transfusions. In turn, RBC are independently associated with worse outcome. Preoperative anemia mainly results from inadequate erythropoiesis owing to iron deficiency. Iron deficiency anemia (IDA) has a complex origin, including either absolute or functional iron deficiency (or iron sequestration). In absolute iron deficiency, iron stores are severely decreased, resulting in anaemia (IDA). Conversely, functional iron deficiency refers to insufficient iron mobilization despite normal or elevated iron stores (iron deficient erythropoiesis, IDE).The most rapid and simple method to correct anaemia is RBC transfusion. More than 30% of cardiac patients receives blood products in the peri-operative phase. However, blood transfusion itself is not without risk: in the setting of cardiac patients, even a single unit of blood transfused is reported to be associated to increased morbidity and mortality. Specifically, blood transfusions in cardiac surgery are associated with infections, ischemic postoperative morbidity, hospital stay, increased early and late mortality, and greater hospital costs. Preoperative correction of iron deficiency, with or without anaemia, is an integral part of the concept of the Patient Blood Management (PBM). Iron supplementation would increase the availability of iron stores and would trigger the process of erythropoiesis; the consequent relative lack of vitamin B12 and folic acid makes fundamental to restore also these 2 vitamins. The objective of this study is to assess whether to implement an adequate correction of IDA and IDE according to current PBM recommendations might reduce RBC transfusion requirements in patients undergoing heart surgery. Data obtained in patients included in the study will be compared to those of a case-control population selected from patients consecutively treated at the same department in the previous 2 years.