WBR0961

Author	[[PageAuthor::Mugilan Poongkunran M.B.B.S [1]]]
Exam Type	ExamType::USMLE Step 3
Main Category	MainCategory::Emergency Room
Sub Category	SubCategory::Hematology
Prompt	[[Prompt::A 30 year old female comes to the emergency department with an episode of bloody vomiting. She was in her usual state this morning but suddenly developed these symptoms. She had similar episodes thrice over the past one year, but never consulted a doctor. She is a known hypertensive on regular medications. Her past history is otherwise insignificant and her family history is positive for similar episodes in her brother. Her menstrual cycles are normal. She sexually active and uses contraceptives. Her vitals are temperature: 36.7 C, blood pressure: 140/80 mmHg, pulse: 80/min and respiration: 15/min. All system examinations are normal. The patient is treated symptomatically and you plan to do a upper GI endoscopy. Her laboratory values are as follows : Hb : 13 g/dl RBC’s : 2.5 million/cmm WBC’s : 6000/cmm Platelets : 250,000/cmm Neutrophils : 60 % Lymphocytes : 32 % MCV : 85 fl ESR : 15mm/hr PT : 13 sec (N 11-15 sec) APTT : 45 sec (N 25-40 sec) BT : 18 min (N 2-7 min) Serum creatinine : 1.2 mg/dl Serum calcium : 9 g/dl Which of the following is the best next step in the management of the patient?]]
Answer A	AnswerA::I.V platelet transfusion
Answer A Explanation	AnswerAExp::''' Incorrect ''' : There is no quantitative platelet loss in this patient that requires platelet transfusion.
Answer B	AnswerB::I.V desmopressin
Answer B Explanation	[[AnswerBExp:: Correct  : Desmopressin (1-desamino-8-D-arginine vasopressin, DDAVP), which works by raising the patient's own plasma levels of vWF by inducing release of vWF stored in the Weibel-Palade bodies in the endothelial cells should be started in this patient.]]
Answer C	AnswerC::Von Willebrand factor transfusion
Answer C Explanation	[[AnswerCExp:: Incorrect  : Patients with type 3 VWD, those with more severe type 1, and those with types 2A, 2B, and 2M disease often require replacement therapy with VWF, particularly in more serious bleeding situations when other measures have failed, or in settings when more prolonged treatment is required.]]
Answer D	AnswerD::Cryoprecipitate infusion
Answer D Explanation	[[AnswerDExp:: Incorrect  : Cryoprecipitate infusion is not a option in patients with VWF deficiency.]]
Answer E	AnswerE::Proceed with the invasive procedure
Answer E Explanation	AnswerEExp::''' Incorrect ''' : This patient has VWF deficiency which has to be corrected with desopressin or VWF supplement before proceeding with any surgery.
Right Answer	RightAnswer::A
Explanation	[[Explanation::Von Willebrand disease (vWD) is the most common hereditary coagulation abnormality described in humans, although it can also be acquired as a result of other medical conditions. It arises from a qualitative or quantitative deficiency of von Willebrand factor (vWF), a multimeric protein that is required for platelet adhesion. There are four types of hereditary vWD. Type 1 vWD (60-80% of all vWD cases), an autosomal dominant disease is a quantitative defect but may not have clearly impaired clotting, most patients usually end up leading a nearly normal life. Type 2 vWD (20-30%) is a qualitative defect and the bleeding tendency can vary between individuals. There are normal levels of vWF, but the multimers are structurally abnormal, or subgroups of large or small multimers are absent. Type 3 is the most severe form of vWD (homozygous for the defective gene) and may have severe mucosal bleeding, no detectable vWF antigen, and may have sufficiently low factor VIII that they have occasional hemarthroses (joint bleeding), as in cases of mild hemophilia. The various types of vWD present with varying degrees of bleeding tendency, usually in the form of easy bruising, nosebleeds and bleeding gums. Women may experience heavy menstrual periods and blood loss during childbirth. Severe internal or joint bleeding is rare (which only occurs in type 3 vWD). When suspected, blood plasma of a patient needs to be investigated for quantitative and qualitative deficiencies of vWF. This is achieved by measuring the amount of vWF in a vWF antigen assay and the functionality of vWF with a glycoprotein (GP)Ib binding assay, a collagen binding assay or, a ristocetin cofactor activity (RiCof) or ristocetin induced platelet agglutination (RIPA) assays. Factor VIII levels are also performed as factor VIII is bound to vWF which protects the factor VIII from rapid breakdown within the blood. Mild cases of vWD can be trialled on desmopressin (1-desamino-8-D-arginine vasopressin, DDAVP) (desmopressin acetate, Stimate), which works by raising the patient's own plasma levels of vWF by inducing release of vWF stored in the Weibel-Palade bodies in the endothelial cells. Educational Objective: References: ]]
Approved	Approved::Yes
Keyword	WBRKeyword::Von Willebrand disease
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