Rationalizing blood transfusion in cardiac surgery: preliminary findings with a red cell volume-based model

Background and Objectives Cardiac surgery, utilizing extracorporeal circulation, is associated with a heavy fluid load that may significantly depress haemoglobin concentration. Thus, considering haemoglobin alone may be an inaccurate method of replacing red cell volume loss. This study was designed to examine the impact on red cell transfusion of a red cell volume-based guideline. Materials and Methods Patients were randomized to receive red cells as dictated by the red cell volume-based guideline or a haemoglobin-based protocol. End-points considered were red cell transfusion and clinical outcome. Results Patients transfused as per the red cell volume-based guideline received significantly less red cells with no associated difference in clinical outcome. Conclusion Considering haemoglobin concentration alone may significantly overestimate the requirement for red cell transfusion in elective cardiac surgery patients.