9: Bleeding And Clotting Disorders

Question 1

Primary vs secondary hemostasis deficit

Answer 1

Primary: platelet disorder
Secondary: coagulation factor deficiency or inhibitor

Question 2

Four things to measure when suspecting a bleeding disorder

Answer 2

1. CBC
2. Bleeding time or platelet function assay (PFA)
3. PT and PTT
4. Fibrinogen

Question 3

Why is genetic testing important for hemophilia?

Answer 3

1. Confirms diagnosis
2. Predicts severity of disease
3. Eliminates other diseases in differential

Question 4

Explain a Mixing Study

Answer 4

1. In a deficiency, adding the normal factor will fully correct a coag test
2. If issue has to do with an inhibitor, adding more of the factor will not correct it

Question 5

How can hemophilia A patients get acquired hemophilia too?

Answer 5

As they are given recombinant factor VIII, they can develop Abs to this

Question 6

Virchow’s triad for clotting

Answer 6

1. Venous stasis: hospital stays, travel
2. Endothelial injury: trauma, implants
3. Hypercoagulability: genetics, hyper-viscocity from malignancy, auto-immune and inflammatory conditions, smoking cigarettes, contraceptive

Question 7

Common risk factors for DVT

Answer 7

1. Prior PE/DVT
2. Malignancy
3. Recent hospitalization, surgery, or fracture
4. Immobilization (traveling, etc.)
5. Obesity
6. Age > 65

Question 8

D dimer comes from what?

Answer 8

Degradation of cross-linked fibrin

Question 9

D dimer has high negative predictive value. Explain that

Answer 9

If D dimer is negative, youre not dealing with a clot

Question 10

Name some acquired vs congenital hypercoagulable states

Answer 10

Acquired: oral contraceptives, smoking, APA
Congenital: Factor V Leiden, prothrombin gene mutation, antithrombin III deficiency, protein S or C deficiency

Question 11

White vs red thrombus

Answer 11

White: arterial, platelet rich, occur in coronary and cerebral arteries -> atherosclerosis
Red: venous, red cell rich, lower extremities, due to stasis

Question 12

Paradoxical embolism and how it usually happens

Answer 12

Passage of embolus from venous to arterial circulation, most commonly from a patent foramen ovale

Question 13

How to Dx paradoxical embolism**

Answer 13

TTE or TEE, transesophageal echocardiography with bubble study

Question 14

What % of pts with stroke under 55 years old have patent foramen ovale?

Answer 14

50-60%