Bleeding Disorders and Coagulopathies

Question 1

Where does heparin work?

Answer 1

Multiple sites, including intrinsic system

Question 2

How is warfarin measured?

Answer 2

INR

Question 3

How is heparin measured?

Answer 3

Platelet count

Question 4

What does APTT measure?

Answer 4

Heparin
Factor VIII
Factor IX

Question 5

What constitutes a coagulation profile?

Answer 5

Platelet count
APTT
PT

Question 6

What tests can measure dabigatran levels?

Answer 6

Thrombin clotting time (TCT)

Drug levels

Question 7

What tests can measure rivaroxaban and apixaban levels?

Answer 7

Anti-Xa levels

Question 8

What is a common treatment if a person is too anticoagulated?

Answer 8

Prothrombinex

Question 9

What is the lifespan of platelets?

Answer 9

8-9 days

Question 10

How can the effects of clopidogrel and aspirin be reversed?

Answer 10

Platelet transfusion

Question 11

If platelet transfusion fails, what else can be done to reverse the effects of clopidogrel and aspirin?

Answer 11

Desmopressin

Recombinant factor VIIa

Question 12

What is the clinical evaluation of bleeding disorders?

Answer 12

Age at onset
Spontaneous/post-traumatic
Sites/frequency of bleeds/quantitation of bleeding
Bleeding stressors; eg:
- Tooth extractions
- Surgery
FHx
Medications
Therapy received and response
Convincing evidence of "excessive bleeding"

Question 13

What does von Willebrand factor do?

Answer 13

Mediates platelet adhesion at site of injury

Stabilises factor VIII in circulation

Question 14

What is type 1 von Willebrand disease?

Answer 14

Partial vWF deficiency

Question 15

What is type 2 von Willebrand disease?

Answer 15

2A - decreased affinity of vWF for platelets due to decrease in multimers
2B - increased affinity of vWF for platelets due to vWF mutation > thrombocytopaenia
2M - decreased platelet binding due to vWF mutation
2N - defective factor VIII binding site > decreased factor VIII levels

Question 16

What is type 3 von Willebrand disease?

Answer 16

Complete vWF deficiency

Question 17

When is von Willebrand disease treated?

Answer 17

Only if symptomatic, rarely prophylactically

Question 18

What is the treatment of von Willebrand disease?

Answer 18

Desmopressin
- Useful for minor procedures
- Effective in type 1
- Causes hyponatraemia
Replacement therapy

Question 19

What is the symptomatic treatment of von Willebrand disease?

Answer 19

Antifibrinolytics - inhibit fibrinolysis > prolong thrombus formation time
- TXA
Oral contraceptives/Mirena to manage periods
Fibrin glue - for nosebleeds

Question 20

What are the investigations for von Willebrand disease?

Answer 20

May be mildly elevated APTT
Initial tests
- Factor VIII levels
- vWF Ag levels
- vWF activity/function test
- Blood group - group O have lower levels
More specialised tests to subtype

Question 21

What are the investigations for haemophilia?

Answer 21

Hb
May be mildly elevated APTT
Normal INR
Initial tests
- Factor VIII and IX levels
- Likely to be levels of 5-30%
Genetic studies

Question 22

What are the clinical manifestations of haemophilia A?

Answer 22

Haemarthrosis
Subcutaneous and IM haematomas
Psoas and retroperitoneal haematomas
Traumatic bleeding
- Delayed bleeding, especially in tooth extractions
- Slow wound healing

Question 23

What is the course and prognosis of haemophilia A?

Answer 23

Nearly normal lifespan with factor VIII replacement

Question 24

What are the differential diagnoses for haemophilia A?

Answer 24

Haemophilia B

von Willebrand’s disease, especially type 2N

Question 25

What is the treatment for haemophilia A?

Answer 25

Factor VIII replacement - Prophylactically in children with severe form Desmopressin, if mild

Question 26

What is the course and prognosis of haemophilia B?

Answer 26

Nearly normal lifespan with factor IX replacement

Question 27

Which of the two is more prevalent: haemophilia A or B?

Answer 27

A

Question 28

What is the treatment for haemophilia B?

Answer 28

Prothrombinex Recombinant factor IX therapy - Given prophylactically in children with severe form

Question 29

What are the investigation results in immune thrombocytopaenia purpura?

Answer 29

Thrombocytopaenia | Abs to several surface platelet Ags

Question 30

What is the treatment for immune thrombocytopaenia purpura?

Answer 30

``` Initially high dose steroids Avoid platelet transfusions IV Ig if bleeding Further treatments - Splenectomy ```

Question 31

What sort of bleeding occurs in thrombocytopaenia?

Answer 31

``` Skin and mucous membranes - Petechiae - Ecchymosis - Haemorrhagic vesicles - Gingival bleeding and epistaxis Menorrhagia GI bleeding Intracranial bleeding ```

Question 32

What is the investigation conducted when APTT is prolonged?

Answer 32

Mixing study = equal parts normal pooled plasma added to patient plasma Significant correction > factor deficiency No correction > inhibitor present

Question 33

What further tests are indicated if there is correction of APTT in a mixing study?

Answer 33

Specific factor assays - VIII - IX - XI - XII

Question 34

What further tests are indicated if there is no correction of APTT in a mixing study?

Answer 34

Lupus anticoagulant

Question 35

What effect does lupus anticoagulant have on clotting?

Answer 35

In vivo - increases clotting | In vitro - increases bleeding

Question 36

What effect does quinine have on clotting?

Answer 36

Can induce lupus inhibitors

Question 37

What happens in consumptive coagulopathy?

Answer 37

Severe bleeding > all coagulants used up > bleeding

Question 38

What will normal screening tests miss?

Answer 38

Mild von Willebrand's disease Mild haemophilia Factor XIII deficiency Platelet function disorders