Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Haematology > Haemostasis and Bleeding Disorders > Flashcards

Haemostasis and Bleeding Disorders Flashcards

1
Q

What occurs during primary haemostasis?

A

Formation of the platelet plug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How is the platelet plug formed?

A

Damaged vessel wall will expose collagen, which stimulates the release of Von Willebrand Factor, which has corresponding proteins to platelets, causing them to adhere to the site of injury. Platelets will then secrete various chemicals to encourage an aggregation of platelets, forming the plug.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where are platelets formed?

A

In the bone marrow

The form via budding from the megakaryocyte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the mean lifespan of a platelet?

A

7-10 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What can cause failure of the platelet plug forming?

A

Vessel wall problems
Platelet problems
Von Willebrand problems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

List some vessel wall problems which can lead to poor platelet plug formation:

A

Loss of collagen via scurvy or old age
Steroids
Antibodies e.g. HSP
Inherited diseases e.g. Marfans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What symptom can occur when there is a loss of collagen?

A

Extensive bruising

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What platelet problems can lead to failure of primary haemostasis?

A

Thrombocytopaenia due to reduced production or increased destruction
Reduced function e.g. anti-platelet drugs
Rarely - inherited problems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Von Willebrand’s disease is autosomal ________

A

Dominant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Von Willebrand’s disease affects men or women more?

A

Affects them equally BUT roughly 80% of presenting patients are female as they tend to notice abnormalities in menstruation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What % of the population are affected by a Von Willebrand disorder?

A

1%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the most common (acquired) cause of primary haemostatic failure?

A

Thrombocytopaenia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

If there is thrombocytopaenia due to bone marrow problems what findings will there be?

A

Pancytopenia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

List some acquired causes of peripheral platelet destruction:

A

Coagulopathy e.g. DIC
Autoimmune (most common)
Hypersplenism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

List some of the consequences of primary haemostatic failure:

A 
Purpura
Mucosal bleeds (e.g. epistaxis, menorrhagia etc)
Intracranial haemorrhage
Retinal haemorrhage
Purpura and petechia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What screening tests are offered for primary haemostatic problems?

A

Full blood count is the only one

Testing VW factor neds to be done by a specialist and is extremely complicated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the main process of secondary haemostasis?

A

Formation of the fibrin clot

18
Q

Outline the basic process of secondary haemostasis:

A

Damaged endothelium releases tissue factor.
Tissue factor and factor 7 initiate haemostasis through activating factors 5 & 10
Factors 5 & 10 activate prothrombin (factor 2) which becomes activated thrombin
Thrombin then activates fibrinogen to form the fibrin clot

19
Q

What is the role of factors 8 and 9?

A

Factor 7 alone will not stimulate enough fibrin, therefore factors 8 and 9 amplify the release of thrombin

20
Q

What disease is associated with factor 8 deficiency?

A

Haemophilia A

21
Q

What disease is associated with factor 9 deficiency?

A

Haemophilia B

22
Q

What can cause failure of fibrin clot formation?

A

Single clotting factor deficiencies (usually hereditary)
Multiple clotting factor deficiencies (usually acquired)
Increased fibrinolysis

23
Q

Which clotting factors require vitamin K for activation?

A

Factors 2, 7, 9 and 10

24
Q

What drug interacts with Vitamin K as its main mechanism of action?

A

Warfarin

25
Q

Other than warfarin use, what else can cause vitamin K deficiencies?

A

Poor diet
Malabsorption
Obstructive jaundice
Neonatal (no gut flora)

26
Q

What is a consequence of new-born not having vitamin K?

A

Haemorrhagic disease of the newborn occurs

27
Q

What is the blood test that tests for broken down fibrin products?

A

D dimer test

28
Q

What is the enzyme responsible for the breakdown of fibrin?

A

Plasmin

29
Q

What is disseminated intravascular coagulation?

A

An excessive and inappropriate activation of the haemostatic system which affects primary and secondary haemostasis.
Causes microvascular thrombus formation and can lead to end organ failure

30
Q

List some causes of DIC?

A

Sepsis
Obstetric emergencies
Malignancy
Hypovolaemic shock

31
Q

What replacement therapies are appropriate for DIC?

A

Platelet transfusions
FFP transfusions
Fibrinogen replacement

32
Q

What screening tests can be done for problems with secondary haemostasis?

A

Prothrombin time –> measures tissue factor and factor 7
Activated Partial thrombin time –> measures 8 and 9
IF PT and APTT are both low this can be suggestive of multiple clotting factor involvement, or a problem with factors 5 nd 10

33
Q

How is haemophilia inherited?

A

X linked

only affects males

34
Q

Which form of haemophilia is more common

A

A (5x more common)

35
Q

What is haemophilia?

A

A disorder which causes abnormal prolonged bleeding that recurs episodically at certain sites.

36
Q

Where does bleeding in haemophilia tend to occur?

A

Medium to large vessels often in ankle, knee, and shoulder joints

37
Q

How does the bleeding in these joints continue to re-occur

A

The initial bleed leads to inflammation of the synovium, which causes formation of small fragile vessels that rupture more readily

38
Q

What are some of the clinical features of haemophilia?

A

Recurrent hemarthroses
Recurrent soft tissue bleeding and bruising in toddlers
Prolonged bleeding post dental extractions, surgery and other invasive procedures

39
Q

How is haemophilia treated?

A

Infusions of either factors 8 or 9 every few days

these factors have very short half lives

40
Q

Define Haemostasis:

A

This is the process of slowing/stopping blood flow

Haematology (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions