platelets and plasma

Question 1

structure of platelets

Answer 1

• Plasma membrane
• Cytoskeleton
• Dense tubular system
• Secretory granules – alpha (eg. VWF4, PF4, plasminogen), dense (eg. Serotonin), lysosome, peroxisome

Question 2

life span of platelets

Answer 2

7-10 days

Question 3

size of platelets

Answer 3

2-5 um

Question 4

PLT type bleeding

thrombocytopenia/thrombocytopathy

Answer 4

• Hx of skin & mucosal bleeding (GI, GU), early post-procedural bleeding (minutes)
• Petechial rash
• WF disease, ITP, congenital thrombocytopathy
• Medication, liver disease, renal failure

Question 5

Haemophilia type bleeding (factor deficiency)

Answer 5

• Hx of muscle/ joint bleeding, late post-procedural bleeding (hours, days)
• Large suffusions, haematomas
• Haemophilia A, B, C

Question 6

Dogmas to tackle

Answer 6

• Liver cirrhosis patients are ‘anticoagulating themselves’, hence prone to bleed
• Procedures and anticoagulation are not safe in liver cirrhosis patients

Question 7

normal haemostasis

Answer 7

• Primary haemostasis – normal PLT count & function
• Coagulation cascade – normal procoagulants (PT, APTT) and anticoagulants (PC,PS,AT) normal FBG level and structure
• Termination
• Fibrinolysis-normal pro-and antifibrinilytics

Question 8

rebalanced haemostasis

Answer 8

Liver Cirrhosis
• Primary haemostasis – low PT count but vWF high, ADAMTS13 very low, increased PLT activation
• Coagulation cascade – low procoagulants and anticoagulants, low fibrinogen but prothombotic FBG structure
• Termination
• Fibrinolysis – low pro- and antifibrinolytics

Question 9

bleeding disorders

Answer 9

• Coagulation cascade
• PLT
• Vascular
• Inherited/acquired