Haematology - Bleeding Disorders

Question 1

What is primary haemostasis?

Answer 1

Platelet adhesion + aggregation

Question 2

What is secondary haemostasis?

Answer 2

Coagulation cascade

Question 3

What causes thrombosis disorders?

Answer 3

Defect in a part of Virchow’s triad

Question 4

What are general symptoms of a patient with vascular defects or platelet disorders?

Answer 4

• Superficial bleeding into skin, mucosal membranes
• Bleeding imediately after injury

Question 5

What are general symptoms of a patient with coagulation disorders?

Answer 5

• Bleeding into deep tissues, muscles, joints
• Delayed, but severe bleeding after injury
• Bleeding often prolonged

Question 6

What are congenital and acquired causes of vascular defects?

Answer 6

Congenital:
- Osler-Weber-Rendu syndrome
- Connective tissue disease (e.g. Ehlers-Danlos Syndrome)

Acquired:
- Senile purpura
- Infection
- Steroids
- Scurvy

Question 7

What are some acquired and congenital causes of decreased platelet function?

Answer 7

Acquired:
- Aspirin
- Cardiopulmonary bypass
- Uraemia

Congenital:
- Storage pool disease
- Thrombasthenia (glycoprotein deficiency

Question 8

What are some causes of thrombocytopenia?

Answer 8

Decreased platelet production:
- Bone marrow failure

Increased platelet destruction:
- Autoimmune Thrombocytopenia Purpura (AITP/ITP)
- Drugs (e.g. heparin)
- DIC
- HUS
- TTP

Question 9

What are some features and management of Acute ITP?

Answer 9

• Children 2-6yrs
• Male:Female = 1:1
• Precedes infection
• Symptom onset = abrupt
• Platelet count <20,000
• Lasts 2-6wks
• Spontaneous remission common, self-limiting

Tx:
- Steroids
- IVIG (if plts low)

Question 10

What are some features + management of Chronic ITP?

Answer 10

• Adults
• Male:Female = 3:1
• No trigger (rarely precedes infection)
• Platelet count <50,000
• Long-term illness with acute flares (long-term relapsing-remitting)

Tx:
- IVIG
- Steroids
- Immune suppression
- TPO agonists
- Splenectomy

Question 11

What is Factor V Leiden and its treatment?

Answer 11

Most common inherited prothrombotic disorder

• Resistance to Protein C results in failure to degrade Factor V leading to a hypercoagulable state
• Pre-disposes to VTE
• Tx: Long-term antioagulation

Question 12

What is Haemophilia A, its inheritance, presentation and management?

Answer 12

• Factor VIII deficiency
• X-linked recessive

Presentation:
- Early in life
- Prolonged bleeding + haemarthrosis after surgery + trauma

Tx:
- AVOID: NSAIDs + IM injections
- Prophylaxis with Fx VIII in severe cases

Question 13

What is Haemophilia B, its inheritance, presentation + management?

Answer 13

• Factor IX deficiency
• X-linked recessive

Presentation:
- Early in life
- Prolonged bleeding. haemarthrosis after surgery + trauma

Tx:
- Fx IX concentrates prophylactically or after bleeding

Question 14

What is seen on clotting studies for haemophilia?

Answer 14

• Increased APTT
• Normal PT
• Decreased FVIII/FIX assay
• Normal plts
• Normal bleeding time

Question 15

What are the different types of vWD and their inheritance pattern?

Answer 15

Type 1: (AD) Low levels of vWF - Quantitative defect
Type 2: (AD) Deficiency in function of vWF compared to level (mutations cause poor function) - Qualitative defect
Type 3: (AR) Absent vWF - Qualitative + Quantitative defect (can present like haemophilia)

Question 16

What is the presentation and management of vWD?

Answer 16

Presentation:
- Bleeding indicative of platelet disorders
- ?Bleeding indicative of coagulation disorders

Tx:
- Prophylaxis in some pts
- Tx of bleeds = tranexamic acid, desmopressin + vWF + FVIII concentrates

Question 17

What is seen on clotting studies for vWD?

Answer 17

• Increased APTT
• Normal PT/INR
• Decreased FVIII
• Decreased vWF Ag (or normal in type 2)
• Normal plts

Question 18

Why is decreased FVIII seen in vWD?

Answer 18

vWF carries FVIII around in circulation

Question 19

What is disseminated intravscular coagulation (DIC), its causes + treatment?

Answer 19

• Widespread activation of coagulation + fibrinolysis
• Clotting factors + platelets are consumed so causes increased risk of bleeding

Causes:
- Malignancy
- Sepsis (MOST COMMON)
- Trauma
- Obstetric complications
- Toxins

Tx:
- Treat cause
- Transfusions (coagulation Fx), FFP, Platelets, Cryo etc.

Question 20

What is antithrombin deficiency, its mode of inheritance, diagnosis and management?

Answer 20

• VTEs develop in unusual locations (e.g. splenic/mesenteric veins)
• Autosomal dominant

Dx: Antithrombin assay

Tx: Long-term anticoagulation with warfarin + argatroban

Question 21

What is seen in Liver Disease?

Answer 21

• Decreased synthesis of Fx II, V, VII, IX, X, XI + fibrinogen
• High levels of Fx VIII + vWF
• Decreased absorption of Vitamin K
• Abnormalities in platelet function
• Prolonged INR/APTT in chronic disease

Question 22

What causes Vitamin K deficiency, what are some differential diagnoses + what is its treatment?

Answer 22

Causes:
- Warfarin
- Vitamin K malabsorption/malnutrition
- Abx therapy
- Biliary obstruction

DDx:
- Liver disease
- Scurvy

Tx:
- IV Vitamin K
- FFP for acute haemorrhage

Question 23

What factors are reliant on vitamin K for their synthesis?

Answer 23

Factors II, VII, IX, X

+ Protein C/S

Question 24

What is seen on clotting studies of Vitamin K deficiency?

Answer 24

• Normal plts
• Normal bleeding time
• Increased APTT
• Increased PT