Hematology / Oncology

Question 1

Heparin:

Does what 4 things?

What pathway?

What is the antidote?

Answer 1

Increase PTT
Activated Antithrombin III

Affects intrinsic Pathway
Decreases fibrinogen

Antidote: Protamine Sulfate

Question 2

Warfarin:

Does what 2 things?

What pathway?

Antidote?

INR goal?

Answer 2

Increases PT
Inhibits Vit K

Teratogenic since its small size crosses placenta

Affects Extrinsic Pathway

Antidote: Vit K

INR goal?

Question 3

Enoxaparin

Is what?

What is special about it?

Inhibits what?

Answer 3

Inhibits Xa

Does’t have to be monitored

Dose is once or twice daily

Question 4

Why do you need to give Heparin-to-Warfarin

Answer 4

Warfarin inhibits proteins C and S before other vitamin K-dependent factors (II, VII, IX, and X)

Leading to paradoxical hypercoagulability before proper anticoagulation

Question 5

Hemophilia

What is it?

Answer 5

Deficiency of a clotting factor

Leads to bleeding diathesis

Subtypes are distinguished by which factor is lacking

Usually hereditary but can be acquired through development of an antibody to a clotting factor

Most Pt are male

Question 6

Hemophilia

Hx / PE

Answer 6

Presents
- Spontaneous Hemorrhage into tissues and joints

• Spontaneous intracerebral hemorrhages, renal and retroperitoneal bleeding and GI bleeding
• Mild cases may have major hemorrhage after surgery or trauma but are otherwise asymtopmatic

Question 7

Hemophilia Dx

PT
aPTT
Thrombin
Fibrinogen
Bleed

Answer 7

• Evaluate for suspected clotting factor deficiency:

PT- Usually Normal
aPTT- Prolonged (more prolonged the more severe the disease)
Thrombin time- Normal
Fibrinogen- Normal
Bleed time- Normal

Conduct a mixing study- Mix pt plasma with normal plasma; if this correct the aPTT, a factor deficiency is likely. If the aPTT doesn’t correct, the pt may have a clotting factor inhibitor

Obtain Factor Assays
- Specific factors VII, VIII, IX, XI and XII.

Hemophilia is characterized according to factor level as follows

Mild: >5% normal
Mod: 1-3% normal
Severe: <1 % normal

Question 8

Hemophilia Tx

Answer 8

Tx bleeding episodes with immediate transfusion of clotting factor to at least 40% of of normal concentration

Factor VIII has 1/2 life of 12 hours, so pt should be dosed BID to maintainequate levels

Mild Hemophiliacs may be treated with Desmopressin (DDAVP) so they should be fluid restricted to prevent the side effect of hyponatremia

Question 9

Subtype of Hemophilia

Answer 9

Hemophilia A- Factor VIII (90%) –X linked

Hemophilia B- Factor IX (9%) – X linked