Other Disorders of Hemostasis

Question 1

Why does heparin cause thrombocytopenia? (HIT)

Answer 1

heparin can form complex with platelet factor 4 and body develops autoantibodies to these complexes and consumes platelets

Question 2

What is DIC?

Answer 2

disseminated intravascular coagulation

abnormal activation of coag cascade - widespread microthrombi cause ischemia and infarction and decreased platelets

Question 3

True or false: DIC is almost always secondary to another disease process

Answer 3

TRUE (obstetric complication, sepsis, adenocarcinoma, acute promyelocytic leukemia, rattlesnake bite)

Question 4

What is the best test for DIC?

Answer 4

D-dimer

Question 5

What do lab findings look like for DIC?

Answer 5

1) LOW platelet count
2) HIGH PT and PTT
3) LOW fibrinogen
4) microangiopathic hemolytic anemia
5) elevated fibrin split products (D-dimer)

Question 6

What is D-dimer?

Answer 6

an elevated fibrin split product

Question 7

What is the final step in clot formation?

Answer 7

lyse the clot (product of lysing crosslinked fibrin is D-dimer)

Question 8

What does D-dimer tell you?

Answer 8

that you have activated the clotting cascade so much so that you get all the way to the end of the cascade where you lyse the clot