Bleeding disorders Flashcards Preview

Module 103, Theme 2: Formation, composition, function and disorders of the blood. > Bleeding disorders > Flashcards

Flashcards in Bleeding disorders Deck (29)
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1

Causes of bleeding

Vascular disorders (rarely)

Platelet disorders

Defective coagulation

2

Thrombocytopenia

Low platelet count

When thrombocyte count <150 x10^9/ L

HOWEVER: symptoms usually occur when count <15

Causes:
Inherited
Acquired: drugs, ITP, DIC.

Symptoms:
GL bleeds
Menorrhagia
Bruising
Epistaxis (nose bleeds)

3

Causes of thrombocytopenia

Inherited:
Glanzmann's

Acquired:
Drug related like aspirin and NSAIDs
ITP- immune thrombocytopenia
DIC- disseminated intravascular coagulation.

4

Symptoms of thrombocytopenia

GI bleeds
Menorrhagia
Epistaxis
Bruising

5

Normal platelet count

Thrombocytes range:

150-400 x 10^9 / L

Thrombocytopenia occurs when count is below range.

Symptoms occur when count is below 15.

6

ITP and its treatment (3)

Immune thrombocytopenia, a type of acquired thrombocytopenia.

Occurs when immune system destroys platelets.

Patients have purpura due to bleeding in the capillaries/ small vessels near the skin.

Treatment:
Steriods
IV immunoglobulins
Splenectomy occasionally.

7

DIC and lab results

Disseminated intravascular coagulation- a type of condition that causes acquired thrombocytopenia.

Blood clots and blacks small blood vessels.

Meningococcal DIC tests show:
High TT, PT and APTT.
Low fibrinogen and platelet levels
Increased D-dimers

8

Vascular bleeding

Occurs when there is a dysfunction in the blood vessel wall.

Can be inherited or acquired.

9

Inherited reasons for vascular bleeding.

Hereditary haemorrhagic telangiectasia (Osler-Weber-Rendu).

Ehlers-Danlos syndrome.

10

Hereditary haemorrhagic telangiectasia.

Autosomal dominant genetic disorder that causes vascular bleeding.

Bleeding into the skin, mucous membranes and organs like the lungs, liver and brain.

11

Inherited haemophillia

Genetic condition that causes deficient blood coagulation due to missing coagulation factors.

Haemophillia A- X-linked related, lack of factor 8.
Haemophilia B- X-linked, lack of factor 9.

12

Clinical features of haemophillia

Joint and muscle bleed

Unexpected post-op bleeds

Joint disease- arthropathy

Haematoma- solid swelling of clotted blood in tissues.

Haemarthrosis- bleeding into the joints.

Family history

13

Tests of coagulation (6)

APTT- activated partial thromboplastin time

PT- partial thromboplastin time

TT- thrombin time

Fibrinogen level

Factor levels

Bleeding time

14

APTT and PT

APTT- activated partial thromboplastin time.
PT- partial thromboplastin time

APTT- assesses the intrinsic coagulation pathway. Involves the factors- VIII, IX, XI and XII

PT- assesses the extrinsic coagulation pathway. Involves the factors- VII, II, V and X.

15

Factors assessed in the APTT test

Factors: VIII, IX, XI and XII

8, 9, 11 and 12

16

Factors assessed in the PT test

Factors: II, V, VII and X

2, 5, 7 and 10.

17

Diagnosis if haemophillia

1. APTT- this will be prolonged. This tests factors: VIII, IX, XI and XII

2. PT- this will be normal. Tests for factors: II, V, VII and X.

3. Test for factors VIII/ IX- this will be low.
<1 %= severe
1-5%= moderate
>5 %= mild.

18

Treatment of haemophilia

Infusion of recombinant factor VIII/ IX so that it is 50-100% of normal concentrations.

Prophylaxis treatment also used for the management of conditions.

19

Risks for haemophilia patients.

HIV, Hep C infections and vCJD

20

von Willebrand disease

A type of haemophillia where there is a deficiency of the von Willebrand factor due to autosomal dominant genetic cause.

Von Willebrand carries factor VIII in the blood and causes platelets to bind to collagen.

Diagnostic test will show:
Low vWF
Low FVIII in the plasma

Signs:
Mucocutaneous bleeds
Epistaxis
Menorrhagia

21

Test for von Willebrand disease

1. APTT- longer. Due to lack of FVIII.

2. Normal PT- extrinsic pathway unaffected.

3. Blood test shows low vWF and FVIII.

4. Prolong bleeding time.

5. Defective platelet function

22

Treatment

Desmopressin- DDAVP
- This is the synthetic version of vasopressin (ADH)

Antifibrinolytics

IV plasma products

23

Acquired causes of haemophilia

Liver disease-
Defective clotting proteins
Impaired platelet function and fibrinolysis.

DIC-
Causes release of pro-coagulant into the blood..
This can causes bleeding.

24

Drugs that cause bleeding disorders

When taken in overdose- excess bleeding.

Iatrogenic- Heparin, Warfarin. Both used to treat cardiovascular problems

Overuse of DOACs

25

Argatroban

A DOAC that directly inhibits thrombin (FII)

26

Apixaban

A DOAC that directly inhibits Factor Xa (prothrombinase)

27

Vitamin K deficiency

Vit K used for gamma carboxylation of factors: II, VII, IX and X.

Causes:
Malabsorption
Biliary obstruction- jaundice in intestine.
Haemorrhagic disease in newborns

28

Pattern of bleeding for vascular and platelet causes

Bleeding into mucous membrane and skin.

29

Pattern of bleeding for coagulation disorders

Bleeding into joint and soft tissue.