Chapter 134. Acquired Bleeding Disorders

Platelet abnormalities, drugs, systemic illness, and endogenous anticoagulants can cause acquired bleeding disorders.

Clinical Features

Patients with thrombocytopenia or dysfunctional platelets commonly present with pethechiae, most evident in the lower extremities. Patients may also exhibit gingival bleeding, epistaxis, purpura, hematuria, and menorrhagia. Splenomegaly may be noted in patients experiencing platelet sequestration.

Diagnosis and Differential

Acquired platelet abnormalities include quantitative (thrombocytopenia) and qualitative (dysfunctional) defects. Quantitative platelet disorders include those caused by decreased platelet production (marrow infiltration, aplastic anemia, drugs, viral infections, and chronic alcohol use), and increased platelet destruction (idiopathic thrombocytopenic purpura (ITP), thrombotic thrombocytopenic purpura (TTP), hemolytic uremic syndrome, disseminated intravascular coagulation (DIC), viral infections, drugs and HELLP syndrome). Other causes include acute hemorrhage, hemodialysis and splenic sequestration. Qualitative platelet disorders are commonly associated with uremia, liver disease, DIC, drugs (aspirin, NSAIDs, clopidogrel), myeloproliferative disorders, and antiplatelet antibodies. Initial laboratory testing should include a CBC with peripheral smear.

Emergency Department Care and Disposition

1. Consult with a hematologist as subtleties in diagnosis and treatment exist. For example, some conditions may be worsened by platelet transfusion (DIC and TTP).

2. Consider platelet transfusion in patients with a platelet count <10 000/mm3 or active bleeding with platelets <50 000/mm3.

3. Treatment and disposition of patients with ITP varies with age, severity, and symptoms. In general, patients with a platelet count >50 000/mm3 require no treatment. Patients with a platelet count <20 000 to 30 000/mm3 and patients with a platelet count of <50 000/mm3 with bleeding typically require treatment. Treatment options include corticosteroids, such as prednisone 60 to 100 milligrams PO daily. Immunoglobulin 1gram/kilogram daily IV is usually reserved for patients with very low platelet counts and bleeding.

Patients with liver disease have an increased risk of bleeding for multiple reasons including decreased synthesis of vitamin K–dependent coagulation factors (II, VII, IX, and X), thrombocytopenia, and increased fibrinolysis.

Emergency Department Care and Disposition

1. Administer vitamin K 10 milligrams PO/IV to patients with significant liver disease who are actively bleeding.

2. Use fresh-frozen plasma 15 mL/kg IV to temporarily replace coagulation factors in patients with active bleeding and coagulopathy, or prior to any invasive procedure.

3. In patients with active bleeding: replace fibrinogen with cryoprecipitate 1 unit/5 kilograms IV if fibrinogen levels <100 milligrams/dL, consider platelet transfusion if thrombocytopenic; desmopressin 0.3 microgram/kilogram SC or IV may shorten bleeding times in some patients.

A variety of hemostatic defects are associated with renal disease including platelet dysfunction due to uremic toxins, deficiency of coagulation factors, and thrombocytopenia.

Emergency Department Care and Disposition

1. Treat acute bleeding with transfusion of packed red blood cells.

2. Hemodialysis improves platelet function transiently for 1 to 2 days.

3. Desmopressin 0.3 microgram/kilogram SC or IV shortens bleeding time in most patients.

4. Conjugated estrogen 0.6 milligram/kilogram ...