Bleeding Disorders

Question 1

name the components of a normal Haemostasis?

Answer 1

-formation of platelet plug (primary)

Formation of fibrin clot (secondary)

Fibrinolysis

+anticoagulant defences

Question 2

Why might a platelet plug fail to form?

Answer 2

vascular problem
Platelet problem
VWF deficiency

Question 3

Give a cause for vascular abnormality

• hereditary?
• Acquired?
• paeds?

Answer 3

• Marfans can mean less collagen in the vessel wall

-Age- loss of collagen
scurvy in alcoholics

-Henoch-Schonlein Purpura

Question 4

Thrombocytopenia

• definition?
• causes? which causes more bleeding?

Answer 4

-reduced platelets

-increased destruction 
reduced production (BM problem) 
BM problem = more bleeding

Question 5

Give the causes of peripheral platelet destruction? (3)

Answer 5

Coagulopathy
(disseminated intravascular coagulation)

Autoimmune
(immune thrombocytopenic purpura (ITP))

Hypersplenism
larger spleen means more platelets pool
may be due to alcoholic liver disease, portal hypertension and back pressure

Question 6

Why might platelets have functional defects? (2)

Answer 6

Drug induced
e.g. Aspirin, NSAIDs

Renal failure
uraemia interferes with platelet function

Question 7

vWF deficiency

• acquired cause?
• inheritance?
• catagories?

Answer 7

• antibody to vWF produced in hypothyroidism, V rare
• autosomal dominant
• varied severity, tends to be women

Question 8

causes of failure of the fibrin clot?

Answer 8

Multiple clotting factor deficiencies
(acquired e.g. DIC)

Single clotting factor deficiency
(hereditary, e.g. haemophilia)

Question 9

cause of multiple clotting factor deficiencies? (3)

-findings in coagulation screen?

Answer 9

liver failure
(hepatocytes synthesise clotting factors)

Vit K deficiency/Warfarin therapy

Complex coagulopathy
e.g. DIC

-prolonged PT
prolonged APTT

Question 10

what clotting factors are carboxylated by Vit K?

• give 2 sources of Vit K?
• where is it absorbed & why?
• give causes of Vit K def?

Answer 10

• II, VII, IX, X
• Diet (broccoli) & intestinal synthesis
• upper intestine as needs bile salts for absorption

-poor dietary intake
malabsorption
obstructive jaundice
Vit K antagonists 
Haemorrhage disease of the newborn

Question 11

Disseminated intravascular coagulation (DIC)

• definition
• give the 2 underlying physiological mechanisms and the clinical signs that result?
• causes?
• treatment?

Answer 11

-excessive and inappropriate activation of the haemostatic system

-microvascular thrombus formation
(end organ failure)

Clotting factor consumption
(bruising, purpura, generalised bleeding)

-sepsis
obstetric emergency
malignancy
hyovolaemic shock

-treat underlying cause
+ replacement therapy:
transfuse platelets and plasma and fibrinogen replacement

Question 12

Haemophilia

• what is it?
• name the 3 types and the underlying mechanisms?
• features (bleeding from which vessels)?
• clinical features if severe (3)
• Investigations? (4)
• treatment?

Answer 12

-An x-linked hereditary disorder in which abnormally prolonged bleeding recurs episodically at one or a few sites on each occasion

-Haemophilia A
(factor VIII deficiency)
Haemophilia B
(factor IX deficiency)
Haemophilia C
(factor XI deficiency)

-platelet levels normal, primary haemostasis functions normally
get bleeding from large & medium blood vessels

-recurrent Haemarthrosis
Recurrent soft tissue bleeds
prolonged bleeding after dental extractions, surgery & invasive procedures
eventual destructive arthropathy due to recurrent bleeding

-PT- normal
ATPP- markedly prolonged
plts- normal

-IV injection of factor 8/9 every 2nd or third day