haemostasis and thrombosis

Question 1

define abnormal bleeding

Answer 1

spontaneous bleeding out of proportion to injury, that is prolonged and/or that restarts after appearing to stop

Question 2

4 common features of bleeding disorder histories

Answer 2

epistaxis (nosebleeds) not stopped by 10 minutes compression; bruising with no apparent trauma; prolonged bleeding from trivial wounds; menorrhagia leading to treatment of anaemia

Question 3

3 primary haemostasis problems

Answer 3

deficiency/defective collagen (age, scurvy, steroids), Von Willebrand disease, drugs or aspirin affecting platelets (or deficient platelets - thrombocytopenia) so platelet plug doesn’t form

Question 4

feature and outcome of Von Willebrand disease

Answer 4

abnormal/no vWF so platelets cannot stick to site of injury as no secondary collagen binding, leading to continuous bleeding

Question 5

bleeding pattern of primary haemostasis problems

Answer 5

no coagulation system so immediate, easy bruising, nosebleeds, prolonged gum bleeding, menorrhagia, bleeding after trauma

Question 6

secondary haemostasis problems

Answer 6

problem with blood coagulation, preventing stabilisation of plug with fibrin, caused by deficiency/defective coagulation factors

Question 7

haemophilia as example of secondary haemostasis problem

Answer 7

prevents thrombin burst as no FVIII, so inadequate fibrin mesh forms to stabilise platelet plug; will fall apart and bleed again

Question 8

example of genetic deficiency

Answer 8

haemophilia - FVIII, FIX

Question 9

examples of acquired deficiency

Answer 9

liver disease (most made in liver), warfarin (inhibits synthesis), dilution (volume replacement), consumption

Question 10

bleeding pattern of secondary haemostasis problem

Answer 10

form unstable platelet plug so delayed and prolonged, deeper inside joints and muscle, not from small cuts, rare nosebleeds, bleeding after trauma/surgery or IM injections

Question 11

fibrinolysis problems

Answer 11

rarer, but excess fibronyltic activity removes fibrin mesh too rapidly

Question 12

2 causes of excess fibrinolytic problems

Answer 12

drug administration (e.g. strokes) or some tumours

Question 13

cause of deficient antifibrinolytic problem

Answer 13

genetic antiplasmin deficiency

Question 14

what is disseminated intravascular coagulation

Answer 14

generalised activation of tissue factors inside vasculature, associated with sepsis, major tissue damage and inflammation

Question 15

feature of disseminated intravascular coagulation

Answer 15

consumes and depletes coagulation factors or platelets, while fibrinolysis depletes fibrinogen

Question 16

what does disseminated intravascular coagulation cause

Answer 16

widespread bleeding from lines, bruising and fibrin deposition to cause organ failure

Question 17

what does a major inflammatory reaction in sepsis caused by disseminated intravascular coagulation cause

Answer 17

inflammatory mediator production (e.g. IL-6)

Question 18

what does IL-6 do

Answer 18

stimulate monocytes or endothelial cells to make tissue factor and express on surface inside blood vessels, so coagulation occurs inside intact blood vessels