anticoagulation

Question 1

what is vichows triad?

Answer 1

hypercoagulability, hemodynamic changes (stasis/turbulence), and endothelial injury/dysfunction

Question 2

what condition results in venous stasis?

Answer 2

AF - atria isnt contracting in predictable manner, clots form and destalises and little fragments break off resulting in arterial thrombus which can lead to stroke

DVT - bed bound, long haul flights, impaired mobility

Question 3

what are indications for anticoagulation?

Answer 3

venous and atrerial thrombotic disease
- AF
-DVT
- pulmonary embolism
- artificial heart valve replacment
- other joint replacements

Question 4

how can hypercoagulability occur?

Answer 4

• AT III, protein C and S deficiency
• hyperhomocysteinemia
• elevated factor VIII
• dysfibrinolysis (saphenous vein with clot forming in the inner part of the wall)
• malignancy

Question 5

what is used in the phophalxis of DVT?

Answer 5

LWMH

Question 6

what does compression socks encourage

Answer 6

graduated in terms of pressure, more compression at the ankles that encourages venous return

Question 7

what is DVT a major problem in?

Answer 7

surgical procedures

Question 8

what score is used to estimate DVT

Answer 8

2-level wells score
- DVT more likely more than 2 points
- PE more likely more than 4 points

Question 9

what is the differential diagnosis to DVT?

Answer 9

cellulitis

Question 10

what is the CHA2DS2Vasc score

Answer 10

C - chronic heart failure (1p)
H - hypertension (1p)
A - age > 75 (2p)
D - diabetes (1p)
S - stroke, TIA or systemic embolism (2p)
V - vascular disease (1p)
A - age 65-74 (1p)
Sc- sex category (1p if female)

Question 11

when would you consider anti-coagulation?

Answer 11

when score is greater than 2

Question 12

what is included in the orbit bleeding score

Answer 12

• > 75 years old (1p)
• reduced haemoglobin, heamatocrit or history of anaemia (2p)
• bleeding history (2p)
• insufficient kidey function eGFR < 60mg/dl (1p)
• treatment with antiplatelet agent

Question 13

what age range would you be cautious in anti-coagulating?

Answer 13

elderly - incresed risk of fall

Question 14

what does HASBLED take into account?

Answer 14

if iNR is abnormal

Question 15

what is the HAS-BLED

Answer 15

1 point each for:
Hypertension
Abnormal renal/liver function (1p for each)
Stroke
Bleeding history
Labile INR
Elderly (over 65)
Drugs/alcohol concomitantly

Question 16

what is an advantage of using warfarin compared to a DOAC

Answer 16

if there is an interaction you can monitor INR and adjust dose

Question 17

what are examples of herbal remedies interacting with warfarin?

Answer 17

glucosamine, st johns wart, cranberry juice

Question 18

how does warfarin work on vitamin K dependant clotting factors?

Answer 18

doesnt act directly, it works on the liver and stops the liver from producing these factors

Question 19

what is the onset of action of warfarin?

Answer 19

24-72hrs

Question 20

what factor do DOACs work on?

Answer 20

factor X

Question 21

what is an examplel of an oral IIa inhibitor?

Answer 21

dabigatran (Pradaxa)

Question 22

when is dual anti-platelets used

Answer 22

after PCI

Question 23

what are example of anticoagulant therapies?

Answer 23

• unfractionated heparin
• LMWH - dalteparin, enoxaparin, tinzaparin
• warfarin
• pentasaccharides - fondaparinux
• dabigatran, rivaroxaban, apixiban, enoxaban

Question 24

how does unfractionated heparin and LWMH exert their anti-coagulant effect?

Answer 24

activating antithrombin which accelerates the inactivation of coagulation enzyme thrombin

Question 25

how is unfractionated heparin administered?

Answer 25

S/C or I/V

Question 26

how is LWMH administered?

Answer 26

S/C

Question 27

what are advantages of LWMH

Answer 27

- longer half life - once daily SC - greater bioavailability - predicable anticoagulant response - reduced haemorrhagic complications - no lab monitoring - no dose adjustment - outpatient treatment of DVT/PE

Question 28

what is the mechanism of action of fondaparinux?

Answer 28

- binds to ATIII, changing its structure to neutralise factor Xa - inhibiton of factor Xa interupts the blood coagulation cascade - prevents formation of thrombin and thrombus - antithrombic treatment of ACS

Question 29

what should vitamin K antagonists not be used as first line therapy?

Answer 29

cerebral artery thrombosis or peripheral artery occlusion

Question 30

what is the dose of aspirin for secondary prevention of DVT/ PE (off label)

Answer 30

75mg or 150mg

Question 31

what is diagnostic testing for blood clotting problems

Answer 31

D-dimer if negative - stop therapeutic anticoagution and think about alternative diagnosis increased D-dimer = break down of clot

Question 32

how to calculate INR?

Answer 32

PT patient/ PTmeannormal

Question 33

what are side effects with high INR?

Answer 33

brusing, gum bleeding, nose bleeds (might not stop)

Question 34

what is the prothrombin time?

Answer 34

checks the extrinsic pathway of the clotting cascade, often used to monitor warfarin therapy and assess vitamin K deficiency

Question 35

what is partial thromboplastin time?

Answer 35

evaluates the intrinsic parthway of the clotting cascade

Question 36

what is activated partial thromboplastic time?

Answer 36

a more sensitive version of the PTT test, often used to monitor therapy due to its faster clotting time with the added activator

Question 37

what is the fennerty loading regimen?

Answer 37

loding dose schedule for warfarin

Question 38

what is dabigatran an inhibitor off?

Answer 38

active thrombin site

Question 39

what is dabigtran CI in?

Answer 39

Crcl<30ml/min (predominantly renal eliminination

Question 40

what are interactions with dabigatran?

Answer 40

P-pg induces eg. rifampacin

Question 41

what are interactions with DOACS

Answer 41

- avoid drugs that are both cyp3a4 and P-gp inhibitors or induces - ketoconazole and ritonavir - carbamazepine

Question 42

what are doacs licensed for?

Answer 42

AF phophalaxis and treatment of thromboembolism

Question 43

what are advantages of doacs

Answer 43

- no INR monitoring -no bridging required - surgical procedures - convienience - fewer interactions - potentially better efficacy and safety

Question 44

whart mare diadvantages of doacs?

Answer 44

- compliance - missed doses - increased GI side effects - lack of monitoring

Question 45

what blood tests would you do before commencing edoxaban?

Answer 45

liver function tests full blood countd renal function

Question 46

why would warfarin be prescribed at 6pm

Answer 46

if bloods are done in the morning they can change the dose before the evening

Question 47

what is the duration of anticoagulation for DVT?

Answer 47

3 months