Bleeding disorders

Question 1

what is the basic pathogenesis behind bleeding disorders

Answer 1

unable to form clots to stop bleeding

ie failure of primary/secondary haemostasis

Question 2

what are the 3 main factors in primary haemostasis

Answer 2

vascular
platelets
VWF

Question 3

list heritable causes of vascular defects in primary haemostatic failure

Answer 3

Marfans syndrome

AD - fibrillin mutation

Question 4

list acquired causes of vascular defects in primary haemostatic failure

Answer 4

old age - loss of collagen
scurvy - Vit C deficiency
vasculitis - HSP

Question 5

what can occur to platelets in primary haemostatic failure

Answer 5

reduced number

reduced function

Question 6

what are causes of reduced platelet count in primary haemostatic failure

Answer 6

reduced production: bone marrow failure

increased destruction: ITP, DIC, hypersplenism

Question 7

what is another finding in bone marrow failure

Answer 7

pancytopaenia

Question 8

what is ITP

Answer 8

immune thrombocytopaenic purpura

autoimmune condition attacking platelets

Question 9

causes of hypersplenism

Answer 9

liver disease and portal hypertension

lymphoma

Question 10

what are causes of reduced platelet function in primary haemostatic failure

Answer 10

drugs - antiplatelets, NSAIDs

renal failure

Question 11

VWF deficiency/excess can result in primary haemostatic failure

Answer 11

deficiency

Question 12

cause of VWF deficiency

Answer 12

AD condition

common

Question 13

symptoms of primary haemostatic failure

Answer 13

bruising 
purpura 
muscosal bleeding: epistaxis, gums, GI, menorrhagia
intracranial bleed 
retinal haemorrhages

Question 14

what are the main categories for secondary haemostatic failure

Answer 14

multiple clotting factor deficiencies

single clotting factor deficiency

Question 15

causes of multiple clotting factor deficiencies

Answer 15

liver disease - NAFLD, ALD, PBC, viral hepatitis
vit K deficiency/warfarin
complex coagulopathy - DIC

Question 16

where are all coagulation factors produced

Answer 16

liver

Question 17

which clotting factors are carboxylated by vitamin K

Answer 17

2,7,9,10

Question 18

what are the sources of Vit K

Answer 18

dietary - green leafy veg

intestinal synthesis

Question 19

where is vit K absorbed

Answer 19

proximal gut

Question 20

what is needed for vit K absorption

Answer 20

bile salts

Question 21

causes of vit K deficiency

Answer 21

reduced dietary intake
^ warfarin
obstructive jaundice
malabsorption

Question 22

what is the action of warfarin

Answer 22

vit K antagonist

Question 23

what is DIC

Answer 23

Disseminated intravascular coagulopathy
Widespread tissue damage and inflammation causes excessive and abnormal haemostasis
Formation of microvascular thrombi resulting in tissue ischaemia and end organ failure
Clots are broken down and there is more bleeding and more clots are formed
clotting factors eventually become depleted

Question 24

management of DIC

Answer 24

platelet, plasma, cryoprecipitate transfusions

ADDRESS THE CAUSE

Question 25

what investigations are useful for secondary haemostatic failure and what are the findings in multiple factor deficiency

Answer 25

prothrombin time
APTT
both prolonged in multiple deficiencies

Question 26

list causes of DIC

Answer 26

sepsis
malignancy - adenocarcinomas (chronic DIC)
obstetric emergencies eg placental abruption
hypovolaemic shock

Question 27

what is a cause of single protein deficiency as part of secondary haemostatic failure

Answer 27

haemophilia

Question 28

women are affected by haemophilia, true or false

Answer 28

FALSE

women are carriers as the condition is X-linked

Question 29

what is the inheritance of haemophilia

Answer 29

X linked

males affected only

Question 30

define haemophilia

Answer 30

X-linked hereditary condition in which there is abnormal prolonged bleeding episodically at 1/few sites on each occasion

Question 31

which clotting factor is deficient in haemophilia A

Answer 31

VIII

Question 32

which clotting factor is deficient in haemophilia B

Answer 32

IX

Question 33

which is more common haemophilia A or B

Answer 33

A

Question 34

pathophysiology of haemophilia

Answer 34

loss of amplification of secondary haemostasis

Question 35

PT and APTT are both very prolonged in haemophilia, true or false

Answer 35

FALSE

only APTT is prolonged (intrinsic pathway with factors VIII/IX)

Question 36

clinical features of haemophilia

Answer 36

recurrent haemarthroses
recurrent soft tissue bleeds
prolonged bleeding after procedure eg dental …

Question 37

what is a consequence of recurrent haemarthroses

Answer 37

iron is damaging to synovium and so eventually patients will need a joint replacement

Question 38

management of haemophilia

Answer 38

intravenous factor VIII/IX every 2 days

huge undertaking for parents