Blood management issues: getting clots together when you want them.

Coagulation is a complex process that allows whole blood to form clots at tissue and vessel sites where damage has occurred. Activation of the hemostasis system causes platelets and fibrin-containing clot to stop the bleeding. Perfusionists must find ways to preserve the coagulation system if we are to avoid bleeding in the cardiopulmonary bypass patient. It is still unclear what techniques are best to continue maintaining hemostasis and avoiding transfusion in patients requiring cardiopulmonary bypass (CPB). There are numerous factors that come into play with the use of CPB including deactivating the coagulation system with anticoagulants, hemodilution of the circulating blood volume, inflammatory response, and a possible pro-coagulant response from protamine with heparin reversal once the surgical procedure has been completed and CPB terminated. All these factors make achieving hemostasis post CPB extremely difficult. This review attempts to assess what is currently being discussed in the literature, which may improve hemostasis with cardiopulmonary bypass. There is still no one technique that will improve hemostasis post CPB. Perhaps the answer may lie in a combination of reported techniques that may in some way lead to the preserving of coagulation factors during CPB.