[Splenic sequestration in patients with sickle cell disease. ]

Splenic sequestration is a potentially life threatening event that is characteristic for sickle cell disease. For reasons unknown a fraction of or even the entire blood volume is trapped in the splenic sinuses within a few hours and thus is no longer available for circulation. The result is splenomegaly, hypovolemia, anemia and extreme reticulocytosis. If the sequestered blood volume is very large the patient goes into fatal hypovolemic shock unless transfused instantly. If the sequestered volume is small there is a chance of spontaneous resolution. The etiology of splenic sequestration is not known. Children with homozygous sickle cell disease (HbSS) are at risk until age 6 years while individuals with compound heterozygous disease (HbSbetaThal, HbSC, HbSD) may develop splenic sequestration even in adulthood. Parents of infants and toddlers with sickle cell disease need to learn how to palpate the spleen in order to detect splenomegaly as early as possible and take the child to the hospital. Splenic sequestration with a drop in hemoglobin of more than 3 g/dl below the patient's usual hemoglobin level is a clear indication for splenectomy regardless of the patient's age as splenic sequestration tends to recur.