Sickle cell disease

10% of black people have this condition in the UK

In the homozygote, deoxygenated HbS becomes insoluble, leading to red cells becoming rigid and sickle shaped

The onset of sickle cell disease is more likely in hypoxia, acidosis, low temperature or cellular dehydration

Sickling is initially reversible but when potassium and water is lost, it becomes irreversible

Local infarction causes:

• Chest pain
• Musculoskeletal pain
• Abdominal pain
• Splenic sequestration
• Haematuria
• Cerebral vascular events (transient ischaemic attacks and cerebrovascular accidents)

Problems

• Anaemia
• Prevention of sickling
• Pre-existing organ damage
• Surgical procedure (sickle related)
• Infection risk

Anaesthetic management

Assessment

• Patients at risk should have HbS test (sickledex)
• However, this does not quantify the amount of HbS, so if +ve, further testing needed
• HbA >40% with total Hb >10 g/dl, but <12 g/dl should be achieved by exchange transfusion
• Assess for pre-existing organ damage
• Avoid sedation (i.e. pre-medication, as it would cause hypoventilation)
• Seek haematological opinion

Conduct

• Normovolaemia
• Good hydration
• Adequate oxygenation
• Pre-oxygenation, hyperventilation can shift oxy-Hb curve to the left and O₂ is more readily bound
• Maintain cardiac output
• Avoid vasoconstrictors
• Monitoring: SaO₂/temperature/urine/hydration
• May need antibiotics

Postoperatively

• Adequate observations
• Good analgesia
• High-dependency unit care given to maintain good hydration and oxygenation
• Avoid shivering