Venous Thromboembolism: Risk Factors

Question 1

What are the common situations/conditions that predispose to VTE?

Answer 1

• Increased risk with advancing age
• Obesity
• Family history of VTE
• Pregnancy (especially puerperium)
• Immobility
• Hospitalisation
• Anaesthesia
• Central venous catheter: femoral >> subclavian

Question 2

What underlying conditions can cause a VTE?

Answer 2

• Malignancy
• Thrombophilia: e.g. Activated protein C resistance, protein C and S deficiency
• Heart failure
• Antiphospholipid syndrome
• Behcet’s
• Polycythaemia
• Nephrotic syndrome
• Sickle cell disease
• Paroxysmal nocturnal haemoglobinuria
• Hyperviscosity syndrome
• Homocystinuria

Question 3

What % of VTEs have no major risk factors to precipitate them?

Answer 3

~40%

Question 4

What medications can cause a VTE?

Answer 4

• COCP
• HRT
• Raloxifene and Tamoxifen
• Antipsychotics

Question 5

Which antipsychotic is thought to most likely cause a VTE?

Answer 5

Olanzapine

Question 6

Regarding the COCP, which generation is more likely to cause a VTE 2nd or 3rd?

Answer 6

3rd generation > 2nd generation

Question 7

Regarding HRT, who is more likely to get a VTE, someone taking oestrogen + progestogen OR those taking oestrogen only?

Answer 7

Higher in women taking oestrogen AND progestogen

Question 8

Name a common 2nd generation COCP

And Name some common 3rd generation COCPs?

Answer 8

• 2nd Generation - Microgynon
• 3rd Generation - Drospirenone, Desogestrel and Gestodene.

REMEMBER 3rd Generation more likely to cause VTE than 2nd.

Question 9

How many more time likely is Dianette (Co-cyprindiol) to cause a VTE than other standard COCPs?

Answer 9

4 times more likely