Haemostasis Flashcards Preview

Y5 Haematology > Haemostasis > Flashcards

Flashcards in Haemostasis Deck (42)
Loading flashcards...
1
Q

What time is checked to monitor heparin therapy? Which pathway does this assess?

A

aPTT, Intrinsic Pathway

2
Q

What is checked to monitor Warfarin therapy? What pathway does this assess?

A

PT (INR), Extrinsic Pathway

3
Q

Which factor starts the Intrinsic pathway in the Coagulation Cascade?

A

Twelve

4
Q

Which factor starts the Extrinsic Pathway in the Clotting Cascade?

A

Seven

5
Q

What factor starts the Common Pathway? And what is used to monitor this pathway?

A

Five, TT (Thrombin time)

6
Q

What 3 components make up Virchows Triad?

A

Vessel Wall, Blood, Blood Flow

7
Q

What is the therepeutic range for INR?

A

2-3 (ideally 2.5)

8
Q

What is given for DVT prophylaxis in ‘at risk’ patients?

A

Daily SC LMWH, TED stockings

9
Q

What antithrombotic molecules are expressed by the vessel wall?

A

Thrombomodulin, EPCR, Tissue Factor Pathway Inhibitor (TFPI), Heparans

10
Q

How does injury/inflammation make the vessel wall prothrombotic?

A

Down regulates anticoag mols, upregulates adhesion mols, expresses TF, decrease prostacyclin production

11
Q

What antiplatelet factors are expressed by the vessel wall?

A

Prostacyclin, NO

12
Q

What 3 factors make up the risk factors of blood in Virchows Triad?

A

Viscosity (Hct, protein/paraprotein), Plt count, Coagulation system

13
Q

What is the treatment for DVT/PE?

A

TEDS +LMWH (175u/kg) + warfarin: LMWH stoped when INR in therepeutic range, Warfarin continued for 3-6 months unless recurrent VTE (give lifelong)

14
Q

How long should you give a cancer patient LMWH after a VTE?

A

3-6 months

15
Q

Which cancer is especially related to VTE’s?

A

Pancreatic

16
Q

What percentage of idiopathic VTE’s are due to cancer?

A

10%

17
Q

How does Heparin work?

A

Potentiates antithrombin III, which inactivates thrombin and factors 9,10, 11

18
Q

How are LMWHs administered and how/when is it monitored?

A

SC once daily, only requires monitoring in late pregnancy and renal failure via anti-Xa assay

19
Q

How is Unfractionated heparin administered and how is it monitored?

A

Given IV, loading dose then infusion, monitor APTT

20
Q

What is the Antidote for Heparin?

A

Protamine Sulphate

21
Q

What are the side effects of Heparins?

A

Bleeding, HIT (heparin induced thrombocytopenia), osteoporosis with long term use

22
Q

How does Warfarin work?

A

Inhibits the reductase enzyme responsible for regenerating the active form of Vit K, therefore inhibits the synthesis of factors 2,7,9, 10, and proteins C, S and Z

23
Q

How is Warfarin monitored and how is its effects reveresed?

A

INR (derived from PT), reversed with IV Vit K/factor concentrates

24
Q

What are the 2 types of Direct Acting Anticoagulants? Give one example of each.

A

Anti-Xa (Rivoraxaban, Apixaban, Edoxaban), Anti-Iia/Anti-Thrombin (Dabigatran)

25
Q

When is the target INR 2.5?

A

1st episode DVT/PE, AF, cardiomyopathy, symptomatic inherited thrombophilia, mural thrombus, cardioversion

26
Q

When is the target INR 3.5?

A

Recurrent DVT/PE, mechanical prosthetic valve (2.5-3.5), coronary artery graft thrombosis, antiphospholipid syndrome

27
Q

Management plan (Warfarin patient): INR 5-8, no bleeding

A

Withold few doses, reduce maintenance. Restart when INR under 5

28
Q

Management plan (Warfarin patient): INR 5-8, minor bleeding

A

Stop warfarin. Vit K slow IV. Restart when INR under 5

29
Q

Management plan (Warfarin patient): INR >8, no bleed/minor bleed

A

Stop warfarin. Vit K (oral/IV, no bleeding/risk factors for bleeding or minor bleeding). Check INR daily

30
Q

Management plan (Warfarin patient): Major bleeding (incl Intracranial haemorrhage)

A

Stop warfarin. Give prothrombin complex concentrate. If unavailable, give FFP. Give Vit K IV.

31
Q

Why does pregnancy increase the risk of a VTE?

A

increases VIII + fibrinogen, decreases proteins, compression on blood flow

32
Q

How does malignancy increase the risk of a VTE?

A

TFs on tumour, inflammation (makes vessel wall prothrombotic), compression on blood flow

33
Q

What is the mortality and recurrence rate of a VTE?

A

5% mortality, 20% recurrence in 2 years

34
Q

List 5 acquired factors that increase the risk of a VTE.

A

Age (>60), BMI >30, Hx DVT/PE, Immobilisation, Major surgery, Long distance travel, malignancy, Pregnancy, HRT, Antiphospholipid Syndrome, Polycythaemia, Thrombocythaemia

35
Q

List 5 Inherited factors that increase the risk of a VTE.

A

Antithrombin deficiency, Protein C def, Protein S def, Factor V Leiden, Prothrombin G20210A, Lupus Anticoag., Coag excess

36
Q

What is the order of factors in the Intrinsic Pathway of the Coagulation Cascade?

A

TwelvE, EleveN, NinE, EighT, TeN –> Five joins it to Common Pathway

37
Q

What turns Fibrinogen into Fibrin?

A

Thrombin

38
Q

What turns Plasminogen into Plasmin?

A

Tissue Plasminogen Activators (TPA)

39
Q

What turns Prothrombin into Thrombin?

A

Factor V (with Calcium + Platelet Factor)

40
Q

What is increased and decreased in DIC? (INR, APTT, Thrombin Time, Plt Ct, Bleeding Time)

A

Increased: INR, APTT, TT, Bleeding time; Decreased: PltCt

41
Q

What is increased and decreased in Liver Disease? (INR, APTT, Thrombin Time, Plt Ct, Bleeding Time)

A

Increased: INR, APTT Decreased: Plt Ct

42
Q

What is increased and decreased in Vit K Def? (INR, APTT, Thrombin Time, Plt Ct, Bleeding Time)

A

Increased: INR, APTT