Medical Emergencies · patient case question
Patient C is diagnosed with von Willebrand disease. Which of the following is NOT a feature of this condition?
Patient case: Bleeding Risk Assessment
demo: 3 patients presenting for extractions on the same morning
chief: Pre-operative hemostasis assessment
history: Patient A: coronary stent, taking aspirin and clopidogrel. Patient B: hemophilia A. Patient C: family history of easy bruising and prolonged bleeding after minor cuts.
meds: See individual histories
findings: All three require routine simple extractions.
Show answer and explanation
Correct answer: A. Isolated prolongation of prothrombin time with normal PTT
- A. Correct — this is the exception. PT is characteristically normal in von Willebrand disease. It is PTT that may be prolonged, because vWF stabilizes factor VIII.
- B. This is a true feature. vWF contributes to vascular integrity, so capillary fragility increases.
- C. This is a true feature. Von Willebrand factor mediates platelet adhesion to subendothelial collagen, so its deficiency impairs adhesion and aggregation.
- D. This is a true feature. Loss of vWF destabilizes factor VIII, lowering its level and prolonging PTT.
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