2021 guideline on patient blood management in cardiac surgery

Intraoperative management

• Topical application of antifibrinolytic agents to the surgical site after cardiopulmonary bypass (CPB) is reasonable to limit chest tube drainage and transfusion requirements after cardiac surgery, although no single topical preparation emerges as the agent of choice for localized bleeding that is difficult to control.
• Goal-directed transfusion algorithms that incorporate point-of-care testing, such as with viscoelastic devices, are recommended to reduce periprocedural bleeding and transfusion in cardiac surgical patients.
• Point-of-care monitoring of the hemostatic system is critical to provide timely and accurate assessment of the cause of bleeding, with potential to provide targeted therapies.
• Prophylactic use of plasma in cardiac surgery in the absence of coagulopathy is not indicated, does not reduce blood loss, and exposes patients to unnecessary risks and complications of allogeneic blood component transfusion.
• Routine use of red cell salvage using centrifugation is helpful for blood conservation and minimizes post-CPB allogeneic red blood cell transfusion in cardiac surgery.
• Direct reinfusion of shed mediastinal blood from postoperative chest tube drainage is not recommended as a means of blood conservation and may cause harm.

Perfusion interventions

• Acute normovolemic hemodilution is a reasonable method to reduce bleeding and transfusion.
• Retrograde autologous priming of the CPB circuit should be used wherever possible.
• Reduced priming volume in the CPB circuit reduces hemodilution and is indicated for blood conservation.
• The adoption of a combined strategy of surgical approach, anesthesia, and perfusion management, along with CPB circuit features designed to minimize hemodilution and optimize biocompatibility, have been termed "minimally invasive extracorporeal circulation" and are reasonable to reduce blood loss and red cell transfusion as part of a combined blood conservation approach.

Postoperative management

• In patients undergoing cardiac surgery, a restrictive perioperative allogeneic RBC transfusion strategy (transfusion trigger between 7 and 8 g/dL) is recommended in preference to a liberal transfusion strategy (transfusion trigger between 8 and 10 g/dL) for perioperative blood conservation. This restrictive strategy reduces both transfusion rate and units of allogeneic RBCs without increased risk of mortality or morbidity.
• Allogeneic RBC transfusion is unlikely to improve oxygen transport when the hemoglobin concentration is greater than 10 g/dL and is not recommended.
• It is reasonable to administer human albumin after cardiac surgery to provide intravascular volume replacement and minimize the need for transfusion.
• Hydroxyethyl starch is not recommended as a volume expander in CPB patients, as it may increase the risk of bleeding.