2.6 Bleeding disorders Flashcards Preview

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Flashcards in 2.6 Bleeding disorders Deck (19):
1

Descibre adhesion

Platelet GPIb-V-Ix binds matrix vWF at high shear causing reversible binding causes adhesion to exposed ECM

2

Describe Activation

Adhesion triggers GPIIb-IIIa activation causing irreversible binding to matrix ligands, shape changes and platelet activation

3

Describe Aggregation

Activated GPIIb-IIIa mediates aggregations via fibrinogen, vWF causing release of granule contents, Microparticles and the recruitment of additional platelets and triggers coagulation

4

What causes Haemophilia A and B?

A: Factor VIII deficiency
B: Factor IX deficiency

5

What is the inheritance of haemophilia A?

X linked recessive

6

What is the classification of haemophilia A?

Mild: >5% normal levels fVIII
Moderate: 1-5%
Severe:

7

What are the clinical manifestations of mild, moderate and severe haemophilia A?

Mild: post trauma/surgical bleeds, spontaneous bleeding uncommon

Moderate: Occasional spontaneous joint bleeds, post traumatic bleeding

Severe: frequent spontaneous bleed from early life, potential joint deformity

8

What are the symptoms of chronic haemophilic arthropathy?

Loss of joint movements
Fixed flexion contractures
Severe muscle wasting
Muscle action imbalance
Crippling deformaties

9

What is the treatment for haemophilia A?

Infusion of factor VIII for prophylaxis

Can also give whole blood, plasma, cryoprecipitate, plasma derived factor VIII, recombinant f VIII, gene therapy

10

What are the complications of haemophilia A?

Recurrent joint bleeding - arthropathy

Severe: increased risk of death from other bleeding events such as intracranial haemorrhage

11

What are the diagnostic factors of haemophilia A and B?

Prolonged APTT and factor assays to confirm deficient factor

12

Which is more common, Haemophilia A or B?

A

13

Which is more common, Haemophilia A or B?

A

14

What are the two roles of vWF?

Carrier protein for Factor VIII

Promote platelet adhesion to subendothelium at high shear rates

15

What is the most common inherited bleeding disorder?

Von Willebrands Disease

16

What is the diagnosis of vWD

Decreased vWF
May have decreased APTT
Defective platelet aggregation (count will be normal)

17

What is the classification of vWD?

1: Quantitative partial deficiency
2: Functional abnormality
3: Complete deficiency

18

What is the treatment for vWD?

DDAVP for type 1 to release the vWF that is present
Plasma derived factor VIII concentrate

19

What are the acquired bleeding disorders?

Thrombocytopenia

Decreased coagulation factors: drug induced, associated with liver disease, secondary to vitamin K deficiency

Abnormal platelet function: NSAIDs, aspirin