Thrombosis and Risk factors for thrombosis Flashcards Preview

Clinical Pathology > Thrombosis and Risk factors for thrombosis > Flashcards

Flashcards in Thrombosis and Risk factors for thrombosis Deck (34):
1

What are the 3 factors that contribute to increased risk of thrombosis (Virchow's triad)?

- Change in blood flow (stasis)

- Change in blood composition (hyper coagulation)

- Damage to vascular endothelium

2

What is the primary pathological reason for arterial thrombosis?

Atherosclerotic plaque formation and rupture

- platelet aggregation and thrombi formation

- increased with obesity, hypertension, smoking, diabetes, family history, inactivity, male,, age

3

What are the main causes for venous thrombi?

Stasis - lack of flow due to venous damage/compression

Hyper coagulability - thrombi composed of FIBRIN rather than platelet aggregation/accumulation

4

How does venous thrombi present?

DVT - swelling, warm, painful to touch

5

What is the main complication of DVT?

Pulmonary embolism

6

What are the clinical presentations of PE?

Syncope
AF (new)
Cough - haemoptysis

7

What are the complications of venous thromboembolism?

- Sudden death
- Post thrombotic syndrome - chronic leg swelling, discomfort, ulceration

8

What is the definition of hospital acquired venous thromboembolism?

VTE within 90 days of discharge

9

What does the care pathway for venous thromboembolism comprise?

1 Assess risk for VTE

2 Assess bleeding risk (due to anti coagulant drugs being view)

3 VTE prophylaxis (mechanical/pharmaceutical depending on bleeding risk)

4 Assess risks

10

What are the risk factors for VTE?

-Cancer/treatment
->60yrs old
-Trauma/surgery
-Dehydration
-Thrombophilias (blood conditions)
-Comorbilities e.g. MI
-Immobility
-HRT/oestrogen
-History of VTE
-Family history of VTE
-Pregnancy
-Obesity (>30 BMI)
-Varicose veins

11

What comprise the pro-coagulant and anti-coagulant factors?

Procoagulant - platelets and clotting factors

Anticoagulant - protein C/S, AT-III, fibrinolytic system

12

What is the general advice for people at risk of VTE?

_ensure they are well hydrated
- ensure they are mobile asap
- Aspirin/other antiplatelts = not adequate prophylaxis

13

Name a mechanical form of VTE prophylaxis?

Compression stockings (increasing compression as you go down leg)

14

What are the pharmacological VTE prophylaxis?

Low dose low molecular weight heparin

Dabigatran - thrombin inhibitor

Apixaban - factor X inhibitor

Fondaparinox - antiXa inhibitor

15

How does heparin induce its effects?

Activates Antithrombin or inhibits Xa (different ways)

16

What does fractionated heparin do?

Blocks Xa and binds to antithrombin (stimulates) in equal amounts

17

What does low molecular weight heparin do?

Binds to both anti Xa and antithrombin but confers more an anti Xa effect

18

Whats does fondapprinux do?

Only binds to anti Xa activity

19

What does dabigatran/ apixaban do?

Bind factor X and thrombin directly

20

What are D-dimers? What are they used for?

Products of fibrin breakdown by plasmin

Elevated D-dimers = fibrin clots have formed and plasmin has broken then down - therefore, exclusion

21

What exclusion tests for PE/DVT are performed?

Wells score

22

What is a useful way to diagnose DVT

CT scan/Ultrasound

23

What is the treatment for DVT/PE?

Low molecular weight heparin then warfarin (overlap)

-Dabigatran (inhibits thrombin)
-apixaban (inhibits factor X)
-Fondaparinux (anti Xa)

24

Whats is the management for VTE (recurrent)?

Warfarin

If because of pregnancy, only temporary so do not consider warfarin

25

What is a thrombopilia?

Acquired/congenital condition of haemostasis mechanism that predisposes individual to thrombosis

26

Name some INHERITED thrombophilia conditions

Protein C/S deficiency

Anti thrombin deficiency

Factor V Leiden

Prothrombin 20210A

27

Name an ACQUIRED thrombophilia condition

Antiphospholipid

28

What are the clinical features of thrombophilias?

-DVT
-PE
-Thrombosis in axillary, portal, cerebral and mesenteric veins

29

What is the function of antithrombin?

Xa and thrombin inhibitor

30

What is the function of protein C? how is it activated?

Thrombin binding to thrombomodulin on endothelium

- complex activates protein C

- anticoagulant (balances coagulant-anticoagulation)

31

What is the function of protein S?

Cofactor of protein C -functions to break down factors 5 and 8 by proteolysis

32

How is protein C/S deficiencies inherited?

Autosomal dominant (50% chance of inheriting in parent = sufferer)

33

What is factor V leiden?

Factor V resistance to protein C cleavage

34

What does prothrombin 20210A do?

Point mutation

Increases prothrombin levels

Decks in Clinical Pathology Class (50):