TTP Pentad
FAT RN: Fever, Anemia (microangiopathic hemolytic), Thrombocytopenia, Renal insufficiency, Neurologic symptoms; ADAMTS13 deficiency; emergent plasmapheresis.
DIC Laboratory Profile
Elevated PT/INR, elevated PTT, low platelets, low fibrinogen, and elevated D-dimer with schistocytes on peripheral blood smear.
von Willebrand Disease
Most common inherited bleeding disorder; mucosal bleeding; normal PT, prolonged or normal PTT (vWF protects Factor VIII); treatment: Desmopressin (DDAVP).
Heparin-Induced Thrombocytopenia (HIT)
Platelet drop > 50% 5–10 days after heparin exposure; antibodies to PF4-heparin complex; paradoxical thrombosis; switch to Argatroban or Fondaparinux.
Primary vs. Secondary Hemostasis Disorders
| Bleeding Disorder | Pathophysiologic Mechanism | Platelet Count & Coagulation Studies | Distinguishing Clinical Hallmarks |
|---|---|---|---|
| Immune Thrombocytopenia (ITP) | Autoantibodies against platelet GPIIb/IIIa receptors -> splenic macrophage destruction | Isolated thrombocytopenia (< 100k); normal PT and PTT | Petechiae, purpura, epistaxis, menorrhagia; Corticosteroids (Prednisone), IVIG, or anti-D immune globulin |
| Thrombotic Thrombocytopenic Purpura (TTP) | Severe deficiency in ADAMTS13 metalloprotease -> ultra-large vWF multimers induce microthrombi | Thrombocytopenia, normal PT/PTT, schistocytes on blood smear, high LDH, low haptoglobin | FAT RN: Fever, Anemia, Thrombocytopenia, Renal, Neurologic; Emergent Plasma Exchange (PEX) |
| Disseminated Intravascular Coagulation (DIC) | Systemic activation of coagulation cascade consuming clotting factors and platelets (sepsis, trauma, malignancy, obstetric) | Low platelets, prolonged PT, prolonged PTT, low fibrinogen, dramatically elevated D-dimer | Oozing from venipuncture sites, cataclysmic bleeding + microvascular thrombosis; treat underlying sepsis/cause |
| Hemophilia A and B | X-linked recessive deficiency of Factor VIII (Hemophilia A) or Factor IX (Hemophilia B) | Normal platelets, normal PT, prolonged PTT (corrects with 1:1 mixing study) | Deep tissue bleeding: hemarthroses, muscle hematomas, post-surgical hemorrhage; recombinant factor replacement |
OMM Board Correlate: Spleen Mechanics & Bleeding Precautions
- Severe Thrombocytopenia Precautions: In patients with severe thrombocytopenia (platelet count < 50,000/μL) or active coagulopathies, HVLA thrust techniques are ABSOLUTELY CONTRAINDICATED due to risk of epidural hematoma and retroperitoneal hemorrhage.
- Splenic Circulation: The spleen receives sympathetic innervation from T5–T9 via the celiac ganglion. In ITP, splenic congestion is managed conservatively; splenic pump techniques are avoided to prevent subcapsular hematoma.
Board Traps & Common Distractors
- In Thrombotic Thrombocytopenic Purpura (TTP), NEVER administer platelet transfusions; infusing platelets feeds the microthrombi formation, precipitating fulminant stroke, myocardial infarction, and death. Plasma exchange (plasmapheresis) is the sole life-saving therapy.
- Heparin-Induced Thrombocytopenia (HIT) is a prothrombotic state; do NOT administer Warfarin as initial monotherapy (causes microvascular thrombosis and skin necrosis due to rapid Protein C depletion); use direct thrombin inhibitors (Argatroban or Bivalirudin) first.
- A prolonged PTT that fails to correct with a 1:1 normal plasma mixing study indicates the presence of a coagulation factor inhibitor (e.g., Lupus Anticoagulant or acquired Factor VIII inhibitor) rather than a simple factor deficiency.