Sickle cell anaemia is characterised by periods of good health with intervening crises

A number of types of crises are recognised:

• thrombotic, 'painful crises'
• acute chest syndrome
• aplastic
• sequestration
• haemolytic anaemia
• pulmonary hypertension

Thrombotic crises

• also known as painful crises or vaso-occlusive crises
• precipitated by infection, dehydration, deoxygenation - • Sickled red blood cells clump together and occlude vessels, resulting in ischaemia of downstream tissues
• painful vaso-occlusive crises should be diagnosed clinically - there isn't one test that can confirm them although tests may be done to exclude other complications
• The most common complaint is of pain, and recurrent episodes may cause irreversible damage, fever often accompanies the pain
• infarcts occur in various organs including the bones (e.g. avascular necrosis of hip, hand-foot syndrome in children, lungs, spleen and brain
• Tx - strong IV pain relief, o2 and IV fluids, haematology input
  • Morphine 0.1mg/kg iv/sc every 20 mins until pain is controlled
  • then 0.05-0.1 mg/kg iv/sc every 2-4 hours

Sequestration crises

• sickling within organs such as the spleen or lungs causes pooling of blood with worsening of the anaemia