Bleeding disorders

Question 1

Causes of bleeding

Answer 1

Vascular disorders (rarely)

Platelet disorders

Defective coagulation

Question 2

Thrombocytopenia

Answer 2

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)

Question 3

Causes of thrombocytopenia

Answer 3

Inherited:
Glanzmann’s

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

Question 4

Symptoms of thrombocytopenia

Answer 4

GI bleeds
Menorrhagia
Epistaxis
Bruising

Question 5

Normal platelet count

Answer 5

Thrombocytes range:

150-400 x 10^9 / L

Thrombocytopenia occurs when count is below range.

Symptoms occur when count is below 15.

Question 6

ITP and its treatment (3)

Answer 6

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.

Question 7

DIC and lab results

Answer 7

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

Question 8

Vascular bleeding

Answer 8

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

Can be inherited or acquired.

Question 9

Inherited reasons for vascular bleeding.

Answer 9

Hereditary haemorrhagic telangiectasia (Osler-Weber-Rendu).

Ehlers-Danlos syndrome.

Question 10

Hereditary haemorrhagic telangiectasia.

Answer 10

Autosomal dominant genetic disorder that causes vascular bleeding.

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

Question 11

Inherited haemophillia

Answer 11

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.

Question 12

Clinical features of haemophillia

Answer 12

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

Question 13

Tests of coagulation (6)

Answer 13

APTT- activated partial thromboplastin time

PT- partial thromboplastin time

TT- thrombin time

Fibrinogen level

Factor levels

Bleeding time

Question 14

APTT and PT

Answer 14

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.

Question 15

Factors assessed in the APTT test

Answer 15

Factors: VIII, IX, XI and XII

8, 9, 11 and 12

Question 16

Factors assessed in the PT test

Answer 16

Factors: II, V, VII and X

2, 5, 7 and 10.

Question 17

Diagnosis if haemophillia

Answer 17

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.

Question 18

Treatment of haemophilia

Answer 18

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

Prophylaxis treatment also used for the management of conditions.

Question 19

Risks for haemophilia patients.

Answer 19

HIV, Hep C infections and vCJD

Question 20

von Willebrand disease

Answer 20

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

Question 21

Test for von Willebrand disease

Answer 21

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

Question 22

Treatment

Answer 22

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

Antifibrinolytics

IV plasma products

Question 23

Acquired causes of haemophilia

Answer 23

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

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

Question 24

Drugs that cause bleeding disorders

Answer 24

When taken in overdose- excess bleeding.

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

Overuse of DOACs

Question 25

Argatroban

Answer 25

A DOAC that directly inhibits thrombin (FII)

Question 26

Apixaban

Answer 26

A DOAC that directly inhibits Factor Xa (prothrombinase)

Question 27

Vitamin K deficiency

Answer 27

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

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

Question 28

Pattern of bleeding for vascular and platelet causes

Answer 28

Bleeding into mucous membrane and skin.

Question 29

Pattern of bleeding for coagulation disorders

Answer 29

Bleeding into joint and soft tissue.