thrombotic disorders

Question 1

elements of haemostasis

Answer 1

primary heamostasis
coagulation cascase
fibrinolysis

Question 2

primary haemostasis

Answer 2

in reponse to damaged vessel

vasoconstriction
platelet adhesion to collagen
platelet aggregation

Question 3

coagulation cascade

Answer 3

to form fibrin –> stable clot

Question 4

fibrinolysis

Answer 4

plasmin when plasminogen is activated (f11 + 12, urokinase, TPA)

breakdown of fibrin network

Question 5

thrombus

Answer 5

clot arising in wrong place

e.g. DVT

Question 6

thromboembolism

Answer 6

clot moving along vessel

e.g. DVT –> PE

Question 7

virchow’s triad

Answer 7

stasis: bed rest, travel
hypercoaguability: pregnancy, trauma
vessel damage: atheroma

Question 8

arterial thrombosus

Answer 8

white clot: mostly platelets and fibrin
most 2ry to atheroma
cause tissue ischaemia and infarction

Question 9

arterial thrombosis risk factors

Answer 9

age 
smoking 
obese
sedentary 
DM 
HTN
high cholesterol 
FHx

Question 10

arterial thrombosis management

Answer 10

1ry prevention: lifestyle, vascular risk factors
acute: thrombolysis, anti-platelets, anti-coags
2ry prevention

Question 11

venous thrombosis

Answer 11

red clot: fibrin and red cells
stasis + hypercoagubility
back pressure

Question 12

risk factors venous thrombosis

Answer 12

age 
pregnant
hormonal Rx e.g. HRT
tissue trauma
surgery 
immobility
obese
systemic disease
FHx

Question 13

systemic disease + venous thrombosis

Answer 13

malignancy
myeloproliferative neoplasms
autoimmune e.g. IBD, SLE

Question 14

diagnosis venous thrombosis

Answer 14

pre-test probability scoring: Wells, Geneva
D-dimer
doppler USS
V/Q scan 
CT pulm anigo

Question 15

aims of venous thrombosis Rx

Answer 15

prevent clot extension
prevent embolisation
prevent recurrence - longterm Rx

Question 16

factor V leiden mutation

Answer 16

actions of protein C inhibiting FV are blocked
resistance to activated protein C
ongoing drive towards thrombin generation and fibrin clot production

Question 17

protein C/S deficiency

Answer 17

usually inactivates F5 and F8

drive to thrombin

Question 18

anti-thrombin normally

Answer 18

potentiates formation complexes between heparin and serum protease so direct blocking effect on thrombin

Question 19

anti-thrombin deficiency

Answer 19

no thrombin blocking and so thrombin generation continues

Question 20

microvascular thrombosis

Answer 20

platelets and/or fibrin
results in diffuse ischaemia
principally DIC

Question 21

DIC

Answer 21

diffuse systemic coagulation activation

• microvascular thrombi: vascular obstruction, ischaemia, multi-organ failure
• depletion of platelets and clotting factors: spontaneous bleeding

Question 22

causes of DIC

Answer 22

sepsis
malignancy
eclampsia
placental abruption