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

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.

Immune Dysfunction After Cardiac Surgery with Cardiopulmonary Bypass: Beneficial Effects of Maintaining Mechanical Ventilation.

UNLABELLED: Cardiac surgery with cardiopulmonary bypass (CPB) induces postoperative immunosuppression and impaired pulmonary function. Maintaining mechanical ventilation (MV) during CPB improves pulmonary function and diminishes postoperative systemic inflammation. However, there are no data about the influence of maintaining MV during CPB on postoperative immune dysfunction. METHODS: Fifty patients were prospectively divided into two groups: without MV during bypass (n = 25) and dead space MV with positive end-expiratory pressure (n = 25). PaO2 (arterial oxygen tension)/FIO2 (inspired oxygen fraction) ratio, CXCL10 (C-X-C motif chemokine 10), CCL2 (chemokine ligand 2), tumor necrosis factor α (TNF-α), interleukin 10 (IL-10), human leukocyte antigen-DR antigen (HLA-DR), monocytic myeloid-derived suppressor cells (Mo-MDSCs, CD14HLA-DR monocytes), and blood cell count were collected before and after surgery. RESULTS: Cardiopulmonary bypass induced a marked immunosuppression with a significant increase in plasmatic levels of TNF-α and IL-10 and a significant decrease in HLA-DR monocytic expression. The postoperative proportion of Mo-MDSCs was subsequently significantly increased. Maintaining MV during CPB significantly improved PaO2/FIO2 ratio and decreased postoperative plasmatic levels of TNF-α and IL-10 compared with patients without MV during CPB. Furthermore, nonventilated patients had a lower lymphocyte count after surgery compared with patients with MV during CPB. CONCLUSION: Our study suggests that maintaining MV during CPB for cardiac surgery decreases postoperative immune dysfunction and could be an interesting strategy to diminish the occurrence of postoperative nosocomial infection without hampering the surgical procedure. However, these findings have to be confirmed in a clinical trial using the incidence of nosocomial infection as an endpoint.