DVT and PE

Question 1

T/F when the legs contract blood travels up the superficial veins of the leg?

Answer 1

False, it goes up the deep

Question 2

What is thrombophilia?

Answer 2

A group of inherited or acquired disordered that increase a person’s likelihood of developing arterial or venous thrombosis

Question 2

What can happen to the actual emboli?

Answer 2

DIssolution

Organisation

Recanalisation

Question 3

What are some causes of hypercoagulability?

Answer 3

Post surgery

Post MI

Malignancy

Anti-phospholipid antibody syndrome (autoimmune)

Nephrotic syndrome

High estrogen: post partum, contraception

Obesity: increase cytokines

Certain inflammatory diseases: inflam bowel disease

Cigarette smoking?

Genetics eg Factor V Laiden mutation, prothrombin mutation, deficiencies in anti-thrombin

Question 3

When are the symptoms of DVT?

Answer 3

They are only present in 50% of cases

Redness, swelling, warmth, pain, tenderness

Question 4

What is the mechanism of the Factor V Laiden mutation? By what factor does it increase risk of DVT

Answer 4

Factor V is usually inhibited by the anti-coagulant activated protein C (APC) however a point mutation in factor V means APC can’t bind.

5 fold increase in the chance of DVT

Question 4

Where are DVTs most commonly present?

Answer 4

Calves

Question 4

What determines the severity of the effect of PE?

Answer 4

Size of the emboli

Presence of overlying lung or cardiovascular disease

Question 6

T/F PE is the 4th major cardiovascular cause of death

Answer 6

False, it’s in the top 3

Question 8

What are some risk factors for venous thrombosis?

Answer 8

Slow blood flow:

Immobility - leg pump

Hyperviscosity of blood

Dehydration

Cardiac failure

Endothelial dysfunction - more important in arterial thrombosis

eg direct trauma, surgical trauma, catheter damage

Question 10

In what percentage of cases does death occur after PE is diagnosed?

Answer 10

12%

Question 11

What percentage of PE patients die within one hour?

Answer 11

10%

Question 11

What are the long term outcomes of DVT?

Answer 11

Varicose veins - dilation of superficial veins

Chronic venous insufficiency - venous statis, chronic oedema, pigmentation and chronic ulceration

Question 12

What is the clinical presentation of PE

Answer 12

Variable SOB, haemoptysis, cough, syncope, pleuritic pain

Question 14

T/F Blood usually travels from superficial veins to deep veins in the leg?

Answer 14

True

Question 15

Where are most clinically significant DVTs present?

Answer 15

Thighs and pelvis - more likely to embolise

Question 16

Where do veno-thrombi most commonly arise?

Answer 16

Deep veins of the legs

Question 17

Where are some other sites of venous thrombosis?

Answer 17

Upper arm

Hepatic and portal veins

Cerebral venous sinuses

Mesenteric veins

Question 18

What are some preventions for DVT?

Answer 18

Exercise

Mobilisation

Prophylactic drugs

Compression stocking

Lifestyle

Question 19

What makes venous thrombi so red in colour?

Answer 19

A relatively high proportion of RBCs cf to fibrin and platelets

Question 21

What is the pathophysiology of PE?

Answer 21

Development of hypoxaemia

Local vaso-occlusion and wide spread reflex vasoconstriction > RV stress, dilation and contractile dysfunction

Constriction of airway distal to bronchi

Decrease pulmonary compliance due to haemorrhage and loss of surfactant

Question 22

What are the 3 factors that make up Virchow’s triad?

Answer 22

Vessel wall

Blood composition

Blood flow

Question 23

What are some outcomes of PE?

Answer 23

DEATH if >60% of vascular bed is occluded

cor pulmonale

dyspnoea

Pulmonary infarction (usually only if underlying cardio disease as bronchial arteries supply O2)

Question 24

Which veins are DVTs most common in?

Answer 24

Popliteal (thigh)

Femoral (thigh and pelvis)