Reduction in requirements for allogeneic blood products: pharmacologic methods

Numerous articles describe the reduction of perioperative bleeding by the therapeutic or prophylactic administration of drugs such as prostacyclin, desmopressin, and natural or synthetic antifibrinolytics.

A review of the literature was carried out to help the reader define the indications of these drugs during cardiopulmonary bypass operations, highlight the questions that remain concerning their indications and modes of action, and suggest future studies to answer these remaining questions.

Prostacyclin reduces platelet trauma induced by extracorporeal circulation but does not effectively reduce postoperative bleeding and transfusion requirements. Desmopressin acts as a "glue," improving platelet adhesion, and may be effective when postoperative bleeding is excessive, but its routine use in cardiac operations cannot be recommended. Natural and synthetic antifibrinolytics inhibit plasmin and plasmin-induced platelet dysfunction. These agents have been shown to decrease bleeding and the need for allogeneic transfusions after open heart operations. However, with antifibrinolytic drugs, the risk of thromboembolic phenomena cannot be neglected. With aprotinin, this risk appears to be minimal when the drug is used at concentrations high enough to inhibit plasma kallikrein also.

Prophylactic antifibrinolytics are efficacious, but their routine use remains controversial, both for economic reasons and for fear of thromboembolic complications.