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Zorluk: OrtaFormulating a Differential Diagnosis

A 28-year-old woman is brought to the emergency department by paramedics after experiencing sudden-onset, severe lower abdominal pain and a syncopal episode at home. She reports that her last menstrual period was 7 weeks ago. Her past medical history is significant for a lifelong tendency to bruise easily, frequent epistaxis, and heavy menstrual bleeding. For her bleeding issues, she occasionally uses a specific nasal spray prescribed by her hematologist.

Vital signs on arrival are: temperature 37.0°C (98.6°F), blood pressure 85/50 mmHg, heart rate 128/min, and respiratory rate 22/min. Physical examination reveals a pale, diaphoretic patient with a distended abdomen exhibiting diffuse tenderness, guarding, and rebound tenderness.

Laboratory studies are as follows:

TestResultReference Range
Hemoglobin7.2 g/dL12.0-15.5 g/dL
Platelet count250,000/µL150,000-400,000/µL
Prothrombin time (PT)12 sec11-14 sec
Activated partial thromboplastin time (aPTT)46 sec25-35 sec
Serum beta-hCG4,500 mIU/mL< 5 mIU/mL (non-pregnant)

The patient is urgently prepped for surgery for a presumed ruptured ectopic pregnancy. In addition to addressing the acute hemorrhage, the surgical team must formulate a care plan for her underlying bleeding diathesis. Which of the following conditions most likely accounts for this patient's underlying hematologic abnormality?

  1. Von Willebrand diseaseCevap
  2. B
    Immune thrombocytopenia
  3. C
    Hemophilia B
  4. D
    Disseminated intravascular coagulation
  5. E
    Hereditary hemorrhagic telangiectasia

Cevap

Von Willebrand disease
The correct diagnosis is von Willebrand disease (vWD). This patient's presentation of lifelong mucocutaneous bleeding (epistaxis, menorrhagia) strongly suggests a primary hemostasis defect. However, her platelet count is normal, and she exhibits an isolated prolongation of the activated partial thromboplastin time (aPTT). Von Willebrand factor (vWF) serves two crucial roles: it bridges platelets to exposed subendothelial collagen (primary hemostasis) and acts as a protective carrier protein for Factor VIII (secondary hemostasis). A deficiency in vWF leads to mucosal bleeding and increased clearance of Factor VIII, resulting in a prolonged aPTT. Furthermore, the history of using a hematologist-prescribed nasal spray strongly suggests desmopressin (DDAVP), which induces the rapid release of stored vWF and Factor VIII from endothelial Weibel-Palade bodies, providing effective temporary hemostasis for patients with mild to moderate vWD.

Adım Adım Çözüm

1
Analyze the acute clinical presentation.
The patient has a ruptured ectopic pregnancy causing acute intra-abdominal hemorrhage and hypovolemic shock (hypotension, tachycardia, low hemoglobin).
To understand the immediate life-threatening condition requiring surgical intervention.
2
Evaluate the chronic history and hematologic laboratory values.
The patient has a lifelong history of mucosal bleeding (epistaxis, heavy menses), normal platelet count, normal PT, and an isolated prolonged aPTT.
To formulate a differential diagnosis for her underlying bleeding diathesis that requires ongoing management during and after surgery.
3
Incorporate the pharmacologic clue.
The patient uses a hematologist-prescribed nasal spray for bleeding, which is characteristic of desmopressin (DDAVP).
DDAVP nasal spray is a standard treatment for mild hemophilia A and von Willebrand disease, as it induces the release of stored vWF and Factor VIII from endothelial cells.
4
Synthesize the findings to identify the most likely underlying condition.
Mucosal bleeding + normal platelets + prolonged aPTT + response to DDAVP = von Willebrand disease.
Von Willebrand factor is necessary for platelet adhesion (preventing mucosal bleeding) and stabilizes Factor VIII (deficiency leads to prolonged aPTT). DDAVP treats both defects simultaneously.

Anahtar Kavram

Von Willebrand disease presents with mucosal bleeding, a normal platelet count, and a normal or prolonged aPTT (due to concurrent Factor VIII reduction). It is effectively treated with desmopressin (DDAVP).
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Formulating a Differential Diagnosis

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