disorders of haemostasis

Question 1

general rules for abnormal haemostasis

Answer 1

lack of a factor (lower production OR increased consumption/clearance) defective factor (genetic or acquired defect eg drugs)

Question 2

disorders of primary haemostasis- platelets

Answer 2

low platelet numbers (THROMBOCYTOPENIA)- due to bone marrow failure eg leukemia, too much clearance (autoimmune thrombocytopenia or disseminaed intravascular coagulation), or pooling in enlarged spleen impaired function (genetic absence of glycoproteins, or acquired due to drugs like aspirin)

Question 3

autoimmune thrombocytopenia

Answer 3

autoantibodies bind to platelet, and these platelets removed by macrophages

Question 4

disorders of primary haemostasis- VWF

Answer 4

VWF needed for binding platelets AND transporting F8 VWD due to deficiency or abnormal function- usually hereditary

Question 5

disorders of primary haemostasis- vessel wall in

Answer 5

can be hereditary vascular disorders or acquired (scurvy, steroids, age)

Question 6

bleeding in primary haemostasis

Answer 6

bleeding IMMEDIATE, often comes from gums, nose, menstrual bleeding, cuts ie superficial severe VWD= haemophilia like bleeding (as low Factor 8)

Question 7

unique feature of thrombocytopenia DIAGRAM

Answer 7

petechiae

Question 8

testing for primary haemostasis disorders

Answer 8

platelet count+ morphology measuring VWF numbers

Question 9

thrombogram DIAGRAM

Answer 9

fr

Question 10

primary platelet plug problem

Answer 10

is fine in small vessels, NOT in large vessels

Question 11

disorders of coagulation-coagulation factor deficiencies

Answer 11

hereditary-factor 8/9 deficient= haemophilia- leads to spontaneous joint and muscle bleeding-HEMARTHROSIS prothrombin ie factor 11- lethal factor 11/12 deficiencies- not as severe ACQUIRED- liver disease, anticoagulants eg warfarin

Question 12

disorders of coagulation- increased consumption

Answer 12

acquired- disseminated intravascular coagulation- overactivation of coagulation= TF overactivated= coagulation factors+ platelets overused and depleted- clots form in organs as well as bleeding in other areas OR autoantibodies

Question 13

bleeding in coagulation disorders

Answer 13

no bleeding of superficial cuts or nosebleeds- bleeding is deep in muscles/joints bleeding delayed rather than immediate often starts then stops, and is prolonged

Question 14

testing coagulation disorders DIAGRAM

Answer 14

screening tests- prothrombin time (for extrinsic pathway ie factor 7 to 10 to 2 (thrombin), activated partial thromboplastin time (for intrinsic pathway ie f12 to 11 to 9 to 10) and full blood count for platelets factor assays (eg counts for F8)

Question 15

disorders of fibrinolysis

Answer 15

hereditary- antiplasmin deficiency acquired- tPA drug, or DIC

Question 16

genetics of disease

Answer 16

haemophilia X linked, VWD autosomal dominant, rest are autosomal recessive (thus less common)

Question 17

treatment of abnormal haemostasis

Answer 17

less production/function- replace factors/platelets- give plasma (contains coagulation factors) increase consumption ie DIC- replace factors immune destruction- immunosurpressants/splenectomy

Question 18

desmopressin

Answer 18

causes rise in VWFt

Question 19

tranexamic acid

Answer 19

prevents fibrinolysis