Thrombotic disorders Flashcards Preview

Module 103, Theme 2: Formation, composition, function and disorders of the blood. > Thrombotic disorders > Flashcards

Flashcards in Thrombotic disorders Deck (18)
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1

DVT

Deep vein thrombosis-
Thrombosis (blood clot), in a deep vein in the leg.

Causes:
Hypercoagulability
Haemodynamic changes
Endothelial injury/ dysfunctions

2

Thrombosis risk factors

Post-operative injury- especially orthopaedic.

Prolonged hospitalisation

Pregnancy

OCP- oral contraceptive pill

Long-haul flights

Cancer

Obesity

IV drug abuse- veins.

3

Hypercoagulability causes for DVT

Late pregnancy

Hyperviscosity

Contraceptives

4

Haemodynamic causes for DVT

Varicose veins

Long immobility

Venous stasis

5

Endothelial injury/dysfunction causes for DVT

Piercings

Bacteria/ foreign materials

Chronic inflammation

Medical implants

6

Clinical presentation of DVT

A lot of the times it is asymptomatic.

Unilateral calf swelling

Heat, pain, redness and hardness in leg.

7

Diagnosis of DVT

Doppler ultrasound:
Shows blood velocity and flow through the colour duplex.
Non-compressible veins indicate a thrombosis.

Wells risk score:
Low score indicates increase predictive value for having a DVT.

D-dimers:
Presence indicates the activation of the clotting cascade.

Low wells score and negative D-dimers test indicate high negative predictive value >99%.

8

Initial treatment of DVT

Low molecular weight heparin is given- Tinzaparin or enoxaparin.

Dosing is calculated according the weight- with no monitoring required.

IF patient has renal failure/ impairment- IV unfractionated heparin is used to maintain APTT 1.5-2.0

9

Later treatment of DVT

1. Oral warfarin is loaded into patients for 3-5 days.

2. Stop LMW heparin when the INR (international normalised ratio) is >2.0, for 2 days.

3. If it is the first DVT- warfarin is administered for 6 months post. If it is the second DVT then warfarin given for lifetime.

10

Pulmonary embolism

Thrombosis in the pulmonary artery- resulting from the mobilisation of a DVT.

Micro-emboli- asymptomatic.
Massive emboli- syncope, death

11

Symptoms of PE

- Pleuritic pain
- Dyspnoea
- Haemoptysis

Could also be:
Tachycardiac
Tachypnoeic
Hypotensive

12

Investigations into PE

CTPA- CT pulmonary angiogram- shows clot in BV.

V/Q scan- radio-isotope that shows underperfusion due to V/Q mismatch. BUT it is affected by underlying lung problems.

ECG:
Sinus tachycardia
AF
Right heart strain
SI, QIII, TIII

CXR: usually normal but there may be linear atelectasis or small effusions

13

Effects of PE

Development of pulmonary HT- 4%

5% mortality with treatment

14

Massive PE treatment

Thrombolysis and IV heparin

15

Standard treatment of PE

LMW heparin injections- Tinzaparin
Better for underlying cancer

Warfarin administered to trager INR 2.5 for 6 months

IVC filteres

DOAC

16

Thrombophilia screen

Screen is done in young patients with VTE

Inherited or acquired.

17

Inherited thrombophilia

Factor V Leiden

Prothrombin gene variant

Anti-thrombin deficiency

Protein C/ S deficiency

18

Acquired thrombophilia

Anti-phospholipid syndrome.