Management of b-Thalassaemia GT66

Question 1

What is the definition of b-thalassaemia major?

Answer 1

Requiring >7 transfusions/yr

Question 2

How many babies are born with thalassaemia worldwide each year?

Answer 2

70,000

Question 3

How many individuals worldwide are asymptomatic thalassaemia carriers?

Answer 3

100 million

Question 4

What is the pathophysiology of thalassaemia syndromes?

Answer 4

Extravascular haemolysis due to the release into the peripheral circulation of damaged red blood cells and erythroid precursors because of a high degree of ineffective erythropoiesis

Question 5

Which systems can be affected by iron overload from multiple transfusions?

Answer 5

Hepatic
Cardiac
Endocrine (pit) - delayed puberty, low bone mass, hypogonadotrophic hypogonadism

Question 6

What is the primary cause of death in over 50% of cases of thalassaemia?

Answer 6

Cardiac failure

Question 7

How many patients in the UK are affected by thalassaemia major or intermedia syndromes?

Answer 7

1000

Question 8

Which countries account for the majority of thalassaemia births in the UK?

Answer 8

India, Pakistan and Bangladesh - 79%

Cypriot - 7%

Question 9

What are the risks to mother and baby with b-thalassaemia?

Answer 9

Mum -

• Cardiomyopathy
• New endocrinopathies off chelation for 9/12
  
  • DM, hypothyroid, hypoparathyroid

Baby -
-FGR

Question 10

Which contraception is contraindicated for women with b-thalassaemia?

Answer 10

None - advised to use despite potentially poor fertility

Question 11

Which interventions for b-thalassaemia are beneficial pre-conceptually?

Answer 11

Aggressive iron chelation
Optimise DM
Ensure euthyroid
Echo, ECG and T2* cardiac MRI <20ms
Liver scan - T2*/Ferriscan <7mg/g iron, +USS
Bone density scan and optimise Vit D (stop bisphosphenates 3/12 before)
Check red cell antibodies

Question 12

How is DM monitored in women with b-thalassaemia?

Answer 12

Serum fructosamine
<300nmol/L for 3/12 prepregnancy is optimal
Equivalent HbA1C 43

Question 13

When should iron chelation be discontinued?

Answer 13

Stop deferasirox and deferiprone 3/12 before conception
Teratogenic T1
Convert to desferrioxamine in T2/3

Question 14

How often should women with b-thalassaemia be seen antenatally?

Answer 14

Monthly until 28/40 and fortnightly thereafter
If DM - monthly fructosamine
Cardiac assessment at 28/40
Thyroid fx if hypothyroid throughout pregnancy
USS every 4/52 from 24/40

Question 15

What should the transfusion regimen be for b-thalassaemia during pregnancy?

Answer 15

Major - regular transfusions to aim Hb >100
Intermedia - Consider if worsening anaemia/FGR; aim Hb > 100 if starts transfusions.

If non-transfused has Hb 80 at 36/40 can avoid

Question 16

Which b-thalassaemia patients should receive thromboprophylaxis?

Answer 16

• Splenectomy or platelets >600 - aspirin
• Splenectomy and platelets > 600 - LMWH + aspirin
• All others if admitted to hospital

Question 17

What are the primary indications for iron chelation in pregnancy for women with b-thalassaemia?

Answer 17

Signs of cardiac decompensation (decreasing ejection fraction)
Desferrioxamine 20/mg/kg 4-5 days a wk from 20-24/40
Consider for severe hepatic iron loading

Question 18

What are the recommedations for intrapartum care?

Answer 18

Group & Save (match if antibodies
T Major - 2g desferrioxamine IV over 24 hrs
CEFM
Active management 3rd stage