45 - Platelet and Bleeding Disorders

Question 1

What is warfarin?

Answer 1

A vitamin K antagonist

Question 2

How do you reverse warfarin?

Answer 2

Give vitamin K

Question 3

The INR of the patient determines how to treat a patient with too much warfarin… What is the scale?

Answer 3

2-3: Normal - no intervention needed
9: Omit dose and give Vitamin K PO (5-10 mg)
Bleeding: Omit dose and give Vitamin K IV (10 mg)

Question 4

What is the most common cause of drug induced, antibody mediated thrombocytopenia?

Answer 4

HIT - heparin induced thrombocytopenia

Question 5

How do you diagnose HIT?

Answer 5

ELISA for anti PF4/heparin antibodies

Question 6

How do you treat HIT?

Answer 6

• Discontinue heparin

- Start another anticoagulant

Question 7

What are the three types of platelet destruction disorders?

Answer 7

• DIC
• TTP
• HUS

Question 8

What is DIC? What are the characteristics of DIC?

Answer 8

Disseminated intravascular coagulation

• Prolonged PT, PTT and thrombin time
• Reduced fibrinogen level
• Coagulation proteins are depleted
• Elevated fibrin degredation products
• D-dimer is increased
• Schistocytes (ripped apart by fibrin forming)

Question 9

What is TTP?

Answer 9

Thrombotic thrombocytopenic purpura

Question 10

What is HUS?

Answer 10

Hemolytic uremic syndrome

Question 11

What are the characteristics of TTP and HUS?

Answer 11

• PT, PTT and fibrinogen levels will all be normal
• This is because coagulation proteins are NOT depleted
• Anemia
• Thrombocytopenia
• LDH elevation

Question 12

If you have a patient with an INR of 10, and he is bleeding, is it appropriate to take him to surgery?

Answer 12

NO

Do NOT go ahead with surgery

** Test Q **

Question 13

What do you need to be able to do for the exam?

Answer 13

Distinguish between

• TTP (thrombotic thrombocytopenic purpura)
• HUS (hemolytic uremic syndrome)
• DIC (disseminated intravascular coagulation)

Question 14

What do you NEED to know about HIT for the exam?

Answer 14

HIT

• When do they get it? (patients get HIT 5-10 days after starting heparin - decreased platelet counts)
• What to test? (platelet factor 4 antibody)
• What else? (stop heparin, place patient on appropriate anticoagulation if they are forming thrombi)

** TEST Q **

Question 15

Who usually gets TTP? Who gets HUS? What are the manifestations?

Answer 15

TTP

• Adults
• Multi-organ failure because of diffuse platelet plugs forming and neurological manifestations

HUS

• Children
• Epidemics, abdominal pain, diarrhea, Ecoli, shigga toxin, kidney failure