Blood Conservation in Cardiac Surgery

The objective of the study is to examine the safety of two different hemoglobin (Hgb)-based transfusion triggers in patients post cardiac surgery.

Nearly 20% of blood transfusions in the United States are given to in patients undergoing cardiac surgery. Despite the many blood conservation techniques that are available, safe, and efficacious for patients, many of these operations continue to be associated with significant amounts of blood usage. We believe that transfusion protocols which employ specific guidelines for transfusion can decrease blood product usage and improve outcomes for patients undergoing cardiac surgery. Our goal is to demonstrate that a carefully chosen trigger can achieve better outcomes.

Our hypothesis is that a transfusion trigger of Hgb 7.5 g/dl will lead to decreased utilization of blood transfusions and will have many positive effects on the patients post cardiac surgery in addition to substantial cost savings. We will use an evidence based approach to observe the relative safety of a conservative transfusion trigger (7.5 g/dl) as compared to a more liberal trigger (9.0 g/dl). We will also study the effect of blood conservation on the incidence of transfusion-related complications such as transfusion related lung injury (TRALI) and infectious complications as well as length of hospital stay, cost and ventilator time.

• Transfusion Reactions
• Post Cardiac Surgery

• Other: Blood transfusion
  Conservative transfusion arm: Subjects randomized to the conservative transfusion arm will receive transfusions of PRBCs post-surgery only when their Hgb level measures < 7.5 g/dl. Blood products should be given to maintain Hgb levels >7.5 g/dl.
• Other: Blood transfusion
  Liberal transfusion arm: Subjects randomized to the liberal transfusion arm will receive transfusions of PRBCs post-surgery only when their Hgb level measures < 9.0 g/dl. Blood products should be given to maintain Hgb levels > 9.0 g/dl.

• Experimental: Conservative Transfusion Arm
  Subjects in the conservative transfusion arm will receive transfusion only when their hemoglobin levels reach 7.5 g/dl.
  Intervention: Other: Blood transfusion
• Active Comparator: Liberal Transfusion Arm
  Subjects in the liberal transfusion arm will receive transfusion only when their hemoglobin levels reach 9.0 g/dl.
  Intervention: Other: Blood transfusion

Inclusion Criteria:

Subjects who meet all of the following criteria will be considered for inclusion in this study:

1. Subjects scheduled to undergo any of the following cardiac surgeries as part of their routine medical care:

   • CABG
   • AVR
   • MVR
   • MV Repair
   • CABG/AVR
   • CABG/MVR
   • CABG/MV Repair
   • Thoracic Aneurysm Repair ± any concomitant cardiac procedure (valve, CABG, etc.)
2. Subjects must be > 18 years of age
3. No prior history of cardiac surgery.
4. Able and willing to give informed consent

Exclusion Criteria:

Subjects who meet any of the following criteria will be excluded from participation in this study:

1. Prior history of cardiac surgery
2. Patients who do not have sufficient time prior to surgery to give proper informed consent (i.e.: immediate, emergency surgery)
3. Patients who are younger than 18 years of age

4. Prior history of

   • bleeding disorders
   • symptomatic anemia (i.e. persistent tachycardia, orthostatic hypotension, persistent pressor requirement)
   • hereditary/acquired coagulopathy
   • platelet defects (e.g.: disseminated intravascular coagulation (DIC), hemophilia, Henoch-Schönlein purpura, hereditary hemorrhagic telangiectasia, thrombocytopenia (ITP, TTP), thrombophilia, Von Willebrand's disease)
5. History of leukemia or any other blood related malignancy
6. History of liver failure
7. Current, or history of, pre-existing medical condition other than current cardiac condition, which in the opinion of the investigator, would place the subject at risk or have the potential to confound interpretation of the study results
8. Participation in another clinical trial
9. Lack of capacity to give informed consent.