DVT

Question 1

Define DVT

Answer 1

DVTs occur in 25-50% of surgical patients and many non-surgical patients. 65% of below knee DVTs are asymptomatic and rarely embolize to the lung.

Question 2

Outline the pathophysiology of DVT

Answer 2

Any disturbance of virchow’s triad (flow, composition and vessel wall) leads to an increased risk of coagulation and clot formation.

Question 3

Give some causes of DVT

Answer 3

• Increased age
• Pregnancy
• Synthetic oestrogen
• Trauma
• Surgery
• Past DVt
• Cancer
• Obesity
• Immobility
• Thrombophillia

Question 4

Give three signs of DVT

Answer 4

-	Calf
o	Tenderness 
o	Warmth
o	Swelling 
o	Erythrema
-	Mild fever
-	Pitting oedema

Question 5

Give for investigations for DVT

Answer 5

D dimer
Ultrasound
Thrombophilia
Look for underlying malignancy

Question 6

Give 9 questions you should ask someone with swollen legs

Answer 6

1) Is it both legs?
2) Are you pregnant/
3) Are you mobile?
4) Any trauma?
5) Any pitting?
6) Past diseases/on drugs?
7) Any pain?
8) Any skin changes?
9) Any oedema elsewhere

Question 7

What is a d dimer test?

Answer 7

o Sensitive but not specific for DVT (also raised in infection, pregnancy, malignancy and post-op)
o A –‘ve result combined with a low pretest clinical probability is sufficient to exclude DVT

Question 8

What is the treatment for DVT?

Answer 8

• LMWH
• Warfarin started at same time
• Stop heparin when INR 2-3
• Inferior vena caval filters

Question 9

How do you prevent DVT happening?

Answer 9

• Stop the pill 4 weeks pre-op
• Mobilize early
• LMWH
• Graduated compression stockings
• Fondaparinux (a factor Xa inhibitor) reduces risk of DVT over LMWH without increasing the risk of bleeding