Bleeding & Coagulation Disorders

◆Pattern of bleeding

• •Mucocutaneous (epistaxis, petechiae, menorrhagia, easy bruising) → platelet or vWF disorder
• •Deep tissue (hemarthrosis, muscle hematoma) → clotting factor disorder (hemophilia)

◆Platelet disorders

• •ITP: isolated thrombocytopenia; anti-platelet IgG; kids self-limit after viral; adults often chronic — steroids/IVIG/rituximab/splenectomy
• •TTP: ADAMTS13 deficiency → unprocessed vWF multimers → MAHA + thrombocytopenia + neuro + renal + fever; plasma exchange (DO NOT give platelets — thrombus)
• •HUS: see anemia note
• •HIT: heparin-induced thrombocytopenia; PF4-heparin antibodies; thrombosis paradoxically; stop heparin + use direct thrombin inhibitor (argatroban) or fondaparinux
• •DIC: consumption of platelets + clotting factors; ↑PT/PTT + ↓platelets + ↑D-dimer + ↓fibrinogen + schistocytes; treat underlying (sepsis, OB, malignancy, trauma)

◆Clotting factor disorders

• •Hemophilia A: factor 8 deficiency; X-linked; ↑PTT; deep tissue/joint bleeds; factor 8 concentrate or desmopressin (releases vWF/factor 8)
• •Hemophilia B: factor 9; same presentation; factor 9 concentrate
• •vWD: most common inherited bleeding disorder; mucocutaneous bleeding + epistaxis + menorrhagia; ↑PTT (factor 8 also low); desmopressin (most types)
• •Vitamin K deficiency: ↑PT then ↑PTT; factors 2, 7, 9, 10 + C, S; vitamin K + FFP
• •Liver disease: all factors low except factor 8
• •Warfarin: targets vitamin K pathway

◆Hypercoagulability (thrombophilias)

• •Factor V Leiden: most common inherited; APC resistance
• •Prothrombin G20210A mutation
• •Antithrombin III deficiency (warfarin-resistant; heparin doesn't work well)
• •Protein C or S deficiency: skin necrosis with warfarin start
• •Antiphospholipid syndrome: arterial AND venous thromboses + recurrent miscarriage + ↑PTT (paradoxically — lupus anticoagulant). Anti-cardiolipin, anti-β2-GP1. Treat warfarin INR 2–3

Lab patterns