Coagulation

Question 1

Enoxaparin reversal

Answer 1

Protamine (reverses IIa not Xa)

Question 2

Plt activation

Answer 2

adenosine diphophate

thrombin

Question 3

Platelet aggregation

Answer 3

binding of fibrinogen to GPIIb/IIIa ->allows coagulation cascade to proceed with fixation of prothrombinase complex -> GPIIb/IIIa binds VWF, fibrinogen

Question 4

LMWH (enoxaparin)

Answer 4

avoid in Cr >2.5

if Cr mod dysfxional then check Xa levels with dose adjustment

Question 5

APLS (unprovoked)

Answer 5

coumadin INR 2-3

NO NOACS

Question 6

Provoked DVT

Answer 6

1st incident - 3-6 months

2nd and beyond lifelong

Question 7

Cancer

Answer 7

A/C as long as cancer active

Question 8

PROVOKED DVT

Answer 8

w/in 3 month
trauma, surgery, immobility, hormonal tx
3-6 mo A/C

Question 9

Unprovoked

Answer 9

No antecedent event OR
Active CA
thormbopilia
fhx
Lifelong A/C

Question 10

Warfarin interactions

Answer 10

Amiodarone INCREASES levels - need to decrease warfarin dose 25-33%

Question 11

A/C d/c prior to cabg

Answer 11

3 hours Bivalirudin
12-24 hours for LMWH (enoxaparin)
24 hours for fondaparinux

Question 12

Fondaparinux (Xa inhibitor)

Answer 12

if need PCI - add UFH - risk of catheter related thrombosis (does not inhibit IIa ie thrombin)
avoid with CrCl<30

Question 13

UFH (anti-thrombin III enhancement) - inactivates IIa ie thrombin IXa and Xa

Answer 13

Heparin induced thrombocytopenia

• usually resolves with d/c of heparin
• may need direct thrombin inhibitor (ie argatroban) to mitigate thrombotic effect of HIT)

Question 14

Bivalirudin, Argatroban - direct thrombin inhibitos

Answer 14

thrombin inhibition without involvement of anti-thrombin III

Question 15

Pt with HIT and ACS

Answer 15

Use bivalirudin

can’t use fondaparinux for PCI because need coadmin of heparin

Question 16

Protamine

Answer 16

revereses heparin through reversal of IIa (not Xa effect)

Question 17

Factor V Leiden

Answer 17

Autosomal dominant

low lifetime risk of DVT (5%)

Question 18

PreCABG d/c A/C

Answer 18

3 hours bivalirudin (DTI)
12-24 hrs LMWH/enoxaparin
24 hrs fondaparinux