Patients can present with bleeding after trauma, during or after a procedure, or secondary to a critical clinical state. Fortunately, the body’s hemostatic processes normally respond by stopping and preventing further bleeding. Clotting requires adequate levels of both platelets and coagulation factors. Disorders of primary hemostasis indicate an abnormality in the blood vessels or platelets, whereas disorders of secondary hemostasis indicate an abnormality in the coagulation factors. The end goal of the coagulation cascade is the formation of the fibrin clot. Prothrombin is converted to thrombin, and thrombin converts fibrinogen to fibrin.

Understanding the coagulation cascade explains the rationale behind commonly ordered screening tests: complete blood count, prothrombin time, and partial thromboplastin time. When the screening tests are normal and bleeding persists, it is important to consider checking a fibrinogen level. Fibrinogen (coagulation factor I) is required to ultimately form the fibrin clot. If this factor is not adequately replaced, the patient will not be able to clot properly. Among the many available blood products used for transfusion are packed red blood cells, platelets, fresh frozen plasma (FFP), and cryoprecipitate. FFP contains the acellular components of whole blood and can be administered for volume expansion and/or the replacement of specific plasma components.