Sickle Cell Anaemia
Epidemiology
1 in 4 chance of disease
50% chance of being a carrier
AUTOSOMAL RECESSIVE disorder causing the production of abnormal Beta globing chains
1 in 4 chance of being disease free
Commonest in Africans but also in India, Middle East and southern Europe
Risk Factors
African
Family history
Pathophysiology
The flexibility of the cells is decreased and they become rigid and take up their characteristic sickle appearance
Don't return to normal when oxygenated
An alteration in the beta-globin chain
Clinical Presentation
Pulmonary hypertension - mean pulmonary artery pressure greater than 25mmHg by right heart catheterisation
Anaemia - chronic haemolysis produces a stable haemoglobin level
Acute chest syndrome - a vaso-occlusive crisis of the pulmonary vasculature
Many problems occur in growth & development, bones, cardiac, neurological, liver, renal, eye and pregnancy
Vaso-occlusive crises - acute pain in the hands and feet owing to vast-occlusion of the small vessels and avascular necrosis of the bone marrow in children
Diagnosis
Blood films
Blood count
Sickle solubility test will be POSITIVE
Hb electrophoresis
Level of Hb is in the range of 60-80 g/L
RAISED RETICULOCYTE COUNT
Sickled erythrocytes shown
Shows 80-95% HbS and absent HbA
Aim for diagnosis at birth (cord blood) to aid prompt pneumococcal prophylaxis
Confirms diagnosis
Treatment
FOLIC ACID to all haemolysis patients
Acute painful attacks
Precipitating factors such as infection, cold and dehydration should be avoided or treated quickly
Anaemia
Analgesia
Oxygen and antibiotics if required
IV fluids
Oral Hydroxycarbamide - increases HbF concentrations
Stem cell transplant
Blood transfusion given for certain cardiac conditions e.g. stroke and heart failure