.Snapshot A 25-year-old woman presents to the emergency room with prolonged bleeding after a dental procedure early that day. She has gone through several gauze packing with no success. Her past medical history includes heavy and prolonged menses. As a child, she had several episodes of unexplained nosebleeds. Labs show normal PT, PTT, and platelet count. Introduction Inherited mixed platelet and coagulation disorder from deficiency in von Willebrand factor (vWF) Genetics autosomal dominant Epidemiology most common inherited bleeding disorder more likely in Caucasians Pathogenesis affects coagulation - vWF carries and protects factor VIII produced by endothelial cells and megakaryocytes intrinsic pathway coagulation defect affects platelets – vWF is important in platelet adherence to endothelial lining platelet aggregation is normal (mediated by fibrinogen) Presentation Symptoms mucocutaneous bleeding epistaxis gingival bleeding petechiae easy bruising menorrhagia increased bleeding after aspirin use Evaluation Normal or ↑ PTT (like hemophilia) Normal PT ↑ bleeding time (unlike hemophilia) CBC normal platelet count and appearance may have anemia Diagnosis by ristocetin cofactor assay tests ability of platelets to bind to ristocetin (artificial endothelial surface) ↓ platelet agglutination Differential Diagnosis Bernard-Soulier syndrome Glanzmann thrombasthenia Hemophilia Treatment DDAVP (desmopressin acetate) releases vWF stored in endothelial cells Factor VIII replacement if refractory to DDAVP contains vWF Prognosis, Prevention, and Complications Prognosis most are mild or moderate in severity Prevention avoid aspirin Complications excessive bleeding
QUESTIONS 1 of 4 1 2 3 4 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.HE.17.4707) A 16-year-old male presents to the emergency department with a hematoma after falling during gym class. He claims that he has a history of prolonged nosebleeds and bruising/bleeding after minor injuries. Physical exam is unrevealing other than the hematoma. Labs are obtained showing an increased bleeding time and an abnormal ristocetin cofactor assay. Coagulation assays reveal an increased partial thromboplastin time (PTT) and but a normal prothrombin time (PT). The patient is given desmopressin and is asked to avoid aspirin. Which of the following findings is most likely directly involved in the etiology of this patient's presentation? QID: 108426 Type & Select Correct Answer 1 Decreased platelet count 8% (28/366) 2 Decreased levels of factor VIII 64% (234/366) 3 Decreased levels of factor IX 7% (26/366) 4 Decreased activity of ADAMTS13 12% (44/366) 5 Decreased plasma fibrinogen 5% (20/366) M 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic
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