Venous Thrombosis

Question 1

types of arterial thrombotic events?

Answer 1

coronary
cerebral
peripheral

Question 2

types of venous thrombotic events?

Answer 2

DVT

PE

Question 3

artery vs vein?

Answer 3

artery has thicker muscle
artery actually pulsates itself
blood pumped through vein via contraction of surrounding muscles

Question 4

what usually causes arterial thrombosis?

Answer 4

atherosclerosis leading to a platelet rich thrombus if plaque ruptures exposing collagen etc

Question 5

treatment of arterial thrombosis?

Answer 5

aspirin and other anti-platelets

modify risk factors

Question 6

what tends to be the problem causing venous thrombosis?

Answer 6

blood stasis (platelets not activated)
static blood tends to congeal and form a fibrin clot via the coagulation cascade

Question 7

management of venous thrombosis?

Answer 7

target fibrin formation

warfarin, anticoagulants etc

Question 8

virchows triad of cause of venous thrombosis?

Answer 8

venous stasis
damage to vessel wall (deterioration of valves due to age, previous clots etc)
hypercoagulable blood (elevated clotting factors due to illness or inherited low levels of naturally occurring anticoagulants such as protein C and S and antithrombin)

Question 9

features of DVT?

Answer 9

limb feels hot, swollen and tender
pitting oedema
high WCC

Question 10

signs of PE?

Answer 10

pleuritic chest pain
tachypnoea
tachycardia
hypoxia
cardiovascular collapse/death
right heart strain on ECG

Question 11

risk factors for venous thromboembolism?

Answer 11

age (damaged vessels and lack of mobility)
obesity
pregnancy
puerperium(6 weeks following childbirth)
oestrogen therapy
previous DVT/PE (damages vessel wall)
trauma/surgery
malignancy
paralysis
infection
thrombophilia
anything that cause reduced mobility

Question 12

stasis related risk factors?

Answer 12

age
obesity
pregnancy
previous DVT/PE
trauma/surgery
malignancy
paralysis

Question 13

vessel wall related risk factors?

Answer 13

age

previous DVT/PE

Question 14

hypercoagulability related risk factors?

Answer 14

age
pregnancy (increased CFs and oestrogen)
puerperium
oestrogen therapy (increases CFs)
trauma/surgery
malignancy
infection
thrombophilia
(increased TF, vWF and CF 8)

Question 15

what part of haemostatic system tends to go wrong in thrombophilia?

Answer 15

anticoagulant defences

Question 16

what is thrombophilia?

Answer 16

familial acquired disorders of the haemostatic mechanism which are likely to predispose to thrombosis

Question 17

potential mechanisms of thrombophilia?

Answer 17

decreased anticoagulant activity
increased coagulation (antiphospholipid syndrome)

Question 18

what are the naturally occurring anticoagulants which can be deficient in families?

Answer 18

anti-thrombin (type of serine protease inhibitor)

protein C and protein S (factor 5 leiden can reduce ability of protein C and S to switch off CF 5)

Question 19

what is hereditary thrombophilia?

Answer 19

group of genetic defects in which affected individuals have an increased tendency to develop premature unusual and recurrent thrombosis

Question 20

causes of hereditary thrombophilia?

Answer 20

presence of factor 5 leiden
prothrombin 20210 mutation
antithrombin deficiency
protein C deficiency
protein S deficiency

Question 21

when would a diagnosis of hereditary thrombophilia be considered?

Answer 21

venous thrombosis <45 years old
recurrent venous thrombosis
unusual venous thrombosis
family history of venous thrombosis
family history of thrombophilia

Question 22

management of hereditary thrombophilia?

Answer 22

advice to avoid risk
short term prophylaxis during periods of known risk
short term anticoagulation to treat thrombotic events
long term anticoagulation if recurrent thrombotic events

Question 23

when does a thrombotic event become likely in thrombophilia?

Answer 23

when there are multiple risk factors

often never have an event if no other risk factors are present

Question 24

risks of recurrent thrombosis in order of highest-lowest risk?

Answer 24

history of previous DVT/PE
spontaneous thrombosis rather than acquired risk factor (e.g immobility or surgery etc)
family history
thrombophilia screen results

Question 25

risk of thrombosis in antiphospholipid syndrome?

Answer 25

stronger risk factor than hereditary thrombophilia

Question 26

features of antiphospholipid syndrome?

Answer 26

recurrent arterial and venous thromboses (including TIA)
recurrent foetal loss
mild thrombocytopaenia

Question 27

pathogenesis of antiphospholipid syndrome?

Answer 27

antibodies lead to a conformational change in beta 2 glycoprotein 1 which leads to activation of both primary and secondary haemostasis and vessel wall abnormalities

Question 28

describe the antibodies in antiphospholipid syndrome

Answer 28

autoantibodies which have specificity for anionic phospholipids
also prolong phospholipid dependant coagulation tests in vitro (prolongs ATPP test even though there isn’t a clotting factor deficiency)
also known as lupus anticoagulants

Question 29

conditions associated with antiphospholipid antibodies?

Answer 29

autoimmune disorders
lymphoproliferative disorders
viral infection
drugs
primary

Question 30

management of antiphospholipid syndrome?

Answer 30

aspirin (venous thrombosis)

warfarin (arterial thrombosis)