Acute splenic sequestration is the sudden pooling of blood in the spleen resulting in anemia, which may be life threatening. This type of crisis occurs most often in young children between 10 and 27 months of age in whom autoinfarction of the spleens has not yet happened.
The cause of this syndrome is unclear; it may be seen in the setting of concurrent bacterial or viral infection.
The diagnostic criteria for acute splenic sequestration include an acutely enlarging spleen, a decrease in hemoglobin level of at least 2 g per dL below baseline, thrombocytopenia often with a platelet count <100,000 per mm,3 leukopenia, and evidence of bone marrow compensation with reticulocytosis.
In its most severe form, acute splenic sequestration results in life-threatening anemia, hypovolemia, and shock. Decreases in the levels of hemoglobin <4 g per dL are associated with 35% mortality rates. It is estimated that as much as 50% of the patient’s red cells can be sequestered in the spleen. Approximately 50% of patients who survive an episode of acute splenic sequestration will experience a recurrence.
Emergency management is aimed at restoring circulatory blood volume and hemodynamic stability. Although
therapy may begin with crystalloid resuscitation, red blood cell transfusions must be given promptly.
Long-term management is complicated because there is a high rate of recurrence of either acute or subacute sequestration. Splenectomy has been advocated when recurrent episodes occur.