Drépanocytose et anesthésie obstétricale

Sickle-cell disease is a hereditary haemolytic anaemia related to inheritance of a mutant version of the βglobin gene that codes for the production of the variant haemoglobin, HbS. Patients with homozygosity for the βS allele and those with another associated haemoglobin genes mutation are prone to develop haemoglobin polymerization when deoxygenation occurs. Distortion of red cells is responsible for chronic haemolysis and vaso-occlusive crises. Pain and especially arthritic pain is the hallmark of sickle-cell disease while acute chest syndrome is the most severe complication. The frequency and severity of painful episodes increase during pregnancy, during and after delivery. There is also a risk of low birth weight or even stillbirth. The aim of blood transfusion during pregnancy is to decrease HbS percentage to less than 40-50%. This can be done by exchange transfusion, regular transfusion or erythrocytapheresis. During and after delivery the aim is to avoid hypoxia, pain, hypovolemia, hypothermia and metabolic acidosis that may induce crisis. Epidural analgesia is recommended. Vaso-occlusive crises are treated by O2 supplementation, intravenous fluids administration and transfusion. Thoracic epidural anaesthesia has been suggested to manage acute chest syndrome.