📊 Primary vs Secondary Hemostasis
• Platelet/vessel wall disorders (primary): mucocutaneous bleeding (petechiae, epistaxis, menorrhagia, bruising). Normal PT/PTT.
• Coagulation factor disorders (secondary): deep bleeding (hemarthrosis, muscle hematomas, delayed bleeding). Prolonged PT or PTT.
🩸 von Willebrand Disease (vWD) – Most Common Inherited Bleeding Disorder
• Usually autosomal dominant. Mucocutaneous bleeding (epistaxis, menorrhagia, easy bruising)
• Labs: prolonged PTT (variable), low vWF antigen, low ristocetin cofactor, low factor VIII
• Treatment: desmopressin (DDAVP) for type 1; factor VIII/vWF concentrate for severe
🩹 Hemophilia A & B (X-linked)
• Hemophilia A: factor VIII deficiency; Hemophilia B (Christmas disease): factor IX deficiency
• Deep bleeding: hemarthrosis (knees, ankles, elbows), muscle hematomas, intracranial hemorrhage
• Labs: prolonged PTT, normal PT, normal platelet count. Factor assays confirm.
• Treatment: factor VIII or IX replacement
⚠️ Red Flags – DIC & Liver Disease
• DIC: prolonged PT, PTT, low fibrinogen, elevated D-dimer, thrombocytopenia. Associated with sepsis, trauma, malignancy.
• Liver disease: prolonged PT (corrects with vitamin K if deficiency), decreased fibrinogen, thrombocytopenia
• Vitamin K deficiency: prolonged PT (first to elevate) → PTT, bleeding (hemorrhagic disease of newborn)
📌 Decision strategy: Platelet-type bleeding (mucocutaneous) → vWD or platelet disorder. Deep bleeding (joint/muscle) → hemophilia. Prolonged PTT only → factor VIII, IX, XI, XII deficiency.