Sickle Cell/Haemoglobinopathies Flashcards
Most common cause of hospital admission?
Painful crises
Most common complication?
Painful crises
Treatment for vaso-occlusive crises?
Adequate analgesics (avoid Pethidine as it causes seizures)
- mild crises may be managed with paracetamol and weak opiods
Admit (if no response to simple analgesia/atypical pain/chest pain/dyspnoea)
Ivf
Supplemental oxygen if required
Ensure warmth
What’s the second most common complication?
ACS
How to treat ACS?
- Antibiotics
- Supplemental oxygen
- Blood transfusion
- top transfusion if Hb is falling or
<6.5 - exchange transfusion if steady state hb is maintained.
- top transfusion if Hb is falling or
- Refer to haem if transfusion required to advise on the transfusion (exchange vs topup)
- Refer to critical care team if hypoxic as ventilate support may be required
- R/O PE - commence therapeutic lmwh until PE is ruled out
Symptoms of ACS?
Fever
Dyspnoea
Tachypnoea
Chest pain (pleuritic)
Cough pain
New infiltrate on CXR
What percentage of SCD pregnancies are complicated by ACS?
7-20%
Management of acute stroke in SCD?
- Acute stroke is a medical emergency and both haemorrhagic and infarctive strokes are associated with SCD.
- Acute stroke should be considered in any patient with SCD presenting with neurological impairment.
- A rapid exchange bloodtransfusion
can decrease neurological damage. - Urgent brain imaging/CT brain
- Call haematologist urgently to refer to exchange transfusion
- Thrombolysis is not indicated in acute stroke secondary to SCD.
What causes Acute anaemia in SCD?
Erythrovirus infection MAY cause it.
Other causes:
Haemorrhage
Splenic sequestration (occasionally)
Malaria (rare)
What causes aplastic crisis in SCD?
- Infection with Eryhtrovirus.
- Causes red cell maturation arrest (stops maturation of rbcs)
- Results in aplastic crises characterised by a reticulocytopaenia
- reticulocyte count should therefore always be requested if pt has an acute anaemia
- Can be transmitted vertically to fetus and cause hydrops fetalis.
What is alpha thalassemia?
- an inherited mutation of the gene for the alpha Haemoglobin chain.
- 1 mutation = carrier. No signs or symptoms of anaemia
- 2 mutated genes = alpha thal minor, mild anaemia, mild symptoms
- 3 mutated genes = alpha that major. Moderate to severe anaemia.
-4 mutated genes= rare; cause stillbirths. Babies usu die shortly after birth.
What is beta thalassemia?
Refers to mutation in the genes that code for beta haemoglobin chain.
- 1 mutated gene= thalassemia minor aka beta thalassemia; mild symptoms and anaemia
- 2 mutated genes = thalassemia major/ Cooley anaemia; moderatento severe anaemia
–beta thalassemia intermediate is a milder form that can form from 2 mutated genes.
What infection precautions should women who are frequently tranfused take?
They are at high risk of transfusion transmitted infection.
– Many will be immunized against Hep B
- test for Hep C (asymptomatic)= commonest cause of post transfusion hepatitis!!!!!
— if positive, check RNA titles and refer to a hepatologist - Penicillin prophylaxis (if splenectomy)
—against encapsulated organisms (N. Meningitidis, strep. Pneumoniae, haemophilus influenzae type b.
—erythromycin if allergic - Vaccinations
— single dose haemophilus influenza type b
—single dose conjugated meningococcal C vaccine
—Pneumococcal vaccine q5yearly
What kind of anaemia does beta-thalassemia major cause?
A severe transfusion dependent anaemia
Homozygous beta thalassemia = inadequate Haemoglobin content in rbcs
What kind of anaemia does beta-thalassemia minor cause?
A mild to moderate microcytic anaemia
- no significant detrimental effect on overall life
T/F. Splenectomy is the mainstay of treatment for beta thalassemia?
False. Mainstay is blood transfusion and iron chelation.
The anterior pituitary is sensitive to iron, so iron chelation is important
— patients may present with delayed puberty and reduced bone mass.
Primary cause of death for beta thalassemia? How is mortality reduced?
Cardiac failure (>50%)
- cardiac iron overload =
- iron also deposits in liver, causing overload
- MRI of heart and liver helps reduce mortality!!!
