Haemostatis and Bleeding Disorders

Question 1

define haemostasis

Answer 1

arrest of bleeding and maintenaince of vascular patency

Question 2

what is the primary stage of haemostasis?

Answer 2

formation of platelet plug

Question 3

what is the secondary stage of haemostasis?

Answer 3

formation of fibrin clot

Question 4

what is the lifespan of platelets and why is this important with regards to surgery?

Answer 4

7-10 days, if someone on anti-platelets need to stop medication week before surgery to achieve normal homeostasis level

Question 5

failure of the platelet pluf formation can be caused by what?

Answer 5

vascular

platelets

Von willebrand factor

Question 6

what are vascular causes of failure to form the platelet plug?

Answer 6

hereditary i.e. marfans

aquired i.e. vasculitis (HS purpura)

inc in age (lack of collagen)

Question 7

what are platlet casues of failure to form platelet plug?

Answer 7

thrombocytopenia (reduced number)

renal disease (reduced function)

Question 8

failure of platelet plug formation can result in what?

Answer 8

spontaneous bruising and purpura

mucosal bleeding

intracranial haemorrhage

retinal haemorrhage

Question 9

what are the three ‘stages’ of platelet plug formation?

Answer 9

initiation

propagation

amplification

Question 10

TF and VIIa activate what?

Answer 10

V and Xa

Question 11

V and Xa activate what?

Answer 11

prthrombin

Question 12

prothrombin is converted to what during platelet plug formation?

Answer 12

thrombin

Question 13

thrombin stimulates further relase of which factors?

Answer 13

VIII and IXa

Question 14

VIII and IXa activate more of which other factors?

Answer 14

V and Xa

Question 15

fibrin is broken down by what?

Answer 15

plasmin

Question 16

what converts plasminogen to plasmin?

Answer 16

tissue plasminogen activator

Question 17

what is looked at in a coagulation screen?

Answer 17

prothrombin time

activated partial thromboplasmin time

FBC

Question 18

what is the prothrombin time measuring?

Answer 18

Tissue factor and VIIa

Question 19

what is the activated partial prothrombin time measuring?

Answer 19

VIII and IXa

Question 20

what is the FBC used to look at in a coagulation screen?

Answer 20

platelet count

Question 21

what is thrombophilia?

Answer 21

deficiency of naturally occuring anti-coagulants

Question 22

what is the commenest cause of primary haemostatic failure?

Answer 22

thrombocytopenia

Question 23

what can cause secondary haemostatic failure (fibrin clot)?

Answer 23

multiple or single clotting factor deficiences

Question 24

what can cause multiple clotting factor deficiencies?

Answer 24

liver failure

Vit K deficiency/warfarin therapy

DIC

Question 25

why does a vit K deficiency affect clotting factors?

Answer 25

required to make 2,7,9,10

Question 26

how can obstrucitve jaundice i.e. pancreatic cancer/gallstones cause a clotting factor deficiency?

Answer 26

need bile salts for absoprtion of Vit K- without vit K can't carboxylate 2,7,9,10

Question 27

what can cause DIC?

Answer 27

sepsis obstetirc emergencies malignancy hypovolaemic shock

Question 28

what is a single clotting factor deficiency?

Answer 28

hameophilia

Question 29

which is more common haemophilia A or B?

Answer 29

A

Question 30

which clotting factor is deficient in haemophilia A and in B?

Answer 30

A - factor VIII B- factor IX

Question 31

what mode of inheritance is haemophilia?

Answer 31

X-linked

Question 32

what occurs in someone with haemophilia?

Answer 32

recurrent haemarthroses, soft tissue bleeds prolonged bleeding after dental extractions/surgery

Question 33

atypical picture of menorrhagia and easy bruising would suggest deficiency of what?

Answer 33

Von Willebrand Factor

Question 34

where do people with haemophilia most commnly suffer haemarthroses?

Answer 34

ankle/knee- this is where you're most liekly to bump/twist

Question 35

elevated PT time would indicate deficeincy in?

Answer 35

TF and VII

Question 36

elevated APTT would indicate deficiency in?

Answer 36

VIII and IX

Question 37

platelet adhesion at injury sites occut via what?

Answer 37

glycoprotein 1b and VWF

Question 38

what is dipyridamole?

Answer 38

phosphodiesterase inhibitor- reduces cAMP production