Diseases and Surgical Procedures

Sickle Cell Disease

Sickle cell disease is hemoglobinopathy with autosomal dominant inheritance. Beta chain of Hgb-A has Valine substituted for glutamine at position 6.

In the homozygote, deoxygenated Hgb-S becomes insoluble leading to red cells becoming rigid and sickle shaped.

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 pains,

Musculoskeletal pain,

Abdominal pain,

Splenic sequestration,

Hematuria

Cerebral vascular events (TIAs and CVAs)

Problems

Anemia

Prevention of sickling

Pre-existing organ damage

Surgical procedure (sickle related)

Infection risk

Anesthetic management

Assessment

Patients at risk should have Hgb-S test (sickledex)

However this does not quantify the amount of Hgb-S so if positive sickledex then further testing is needed

Hgb-A >40% with total Hgb >10g/dl but <12 should be achieved by exchange transfusion

Assess for pre-existing organ damage

Avoid sedation (I.e. pre-med- no hypoventilation)

Seek hematological opinion

Anesthetic Management

Normovolemia

Good hydration

Adequate oxygenation

Pre-oxygenation, hyperventilation can shift oxy-Hgb curve to the left and O2 is more readily bound

Maintain CO

Avoid vasoconstrictors

Monitoring: SpO2/temperature/urine/hydration

May need antibiotics

Post-operative

Adequate observations

Good analgesia

Step down unit (high dependency unit) care given to maintain good hydration and oxygenation

Avoid shivering