Pathophysiology

Question 1

Antiplatelets

Answer 1

Prevent platelet aggregation => less chance of clot formation

Question 2

Anticoagulation

Answer 2

Prevent fibrin formation

Question 3

Thrombolytics

Answer 3

break down fibrin/thrombus/clot but have a high risk of bleeding

Question 4

Heparin works on which pathway

Answer 4

• Intrinsic pathway

- Inactivates IIa and Xa

Question 5

Warfarin inhibits which pathway

Answer 5

• Extrinsic pathway

- Inactivates factor 2, 7, 9, and 10

Question 6

APTT or PTT

• Normal:
• Therapeutic Level

Answer 6

• Measure how effective Heparin is working as a blood thinner/anticoagulant
• Normal PTT = 20-40s
• Therapeutic PTT: 1.5-2.5 x N = 45-70s

Question 7

INR/PT

• Normal level w/o anticoagulation
• Level w/ coagulation

Answer 7

• Measure of anticoagulation. It’s affected by coumadin
• Normal person NOT on warfarin: 1
• On Warfarin: 2-3.5

Question 8

INR goal:

• A. fib/A. flutter:
• Elective CV of a.fib
• DVT or PE:
• Mechanical prosthetic heart valve:

Answer 8

• A. fib/A. flutter: 2-3
• Elective CV of a.fib: 2-3
• DVT or PE: 2-3
• Mechanical prosthetic heart valve: 2.5-3.5

Question 9

How to treat DVT?

How to treat PE?

Answer 9

• DVT: Heparin/LMWH follow by PO anticoagulant x 3 mo. ACCP rec warfarin over dabigatran (Indication for non-valvular a.fib) or rivaroxaban (off label for DVT). Thrombolytics are NOT rec in DVT => risk of bleeding outweight benefits
• PE: same as DVT but thrombolytic may be in massive PE w/ HYPOTN

Question 10

Risk factors for DVT?

Answer 10

• Immobilization/Prolong bed rest
• Estrogen: OCP/HRT/Pregnany
• Cancer
• HIP/Knee surgery
• Advanced age
• High risk medical illness: CHF, MI, AF
• Valvular disorder
• Blood disorder: protein C, S, or anti-thrombin III deficiency & antiphospholipid antibody syndrome.

Question 11

ACCP guidelines 2012 for tx of DVT/PE

• Distal Leg DVT (below knee)
• Proximal leg DVT (thigh) or Arm DVT

Answer 11

Distal Leg:

• No, mild, or mod sx: no treatment => monitor
• Severe sx: tx x 3mo

Proximal leg DVT

• Tx regardless of sx
• 3 mo for provoked by a transient risk factor
• “extended” tx if unprovoked.