Splenic Sequestration Crisis

Splenic sequestration crisis is acute pooling of red cells in the spleen with a rapid fall in haemoglobin and painful splenic enlargement.

• Mostly children with HbSS aged 6 months to 5 years (before autosplenectomy); adults with HbSC or sickle beta thalassaemia retain functioning spleens.

• Defined by haemoglobin fall of 2 g/dL or more from baseline, spleen enlargement of 2 cm or more, and reticulocytosis.

• Triggers: infection.

• Recurrence in 50%; mortality up to 15% if untreated.

• Sudden pallor, weakness, abdominal pain, left upper quadrant mass, tachycardia, hypovolaemic shock.

• Irritability, collapse in infants.

• Fever may precede.

• Haemoglobin falling (often below 6 g/dL), thrombocytopenia, raised reticulocytes, nucleated red cells.

• Palpable enlarged tender spleen; ultrasound confirms.

• Blood cultures, group and crossmatch, haemoglobin electrophoresis.

• Exclude aplastic crisis (low reticulocytes), haemolytic crisis.

• Urgent resuscitation: IV isotonic fluids, oxygen.

• Transfusion with packed red cells 5 to 10 mL/kg (small aliquots, as sequestered cells release and haemoglobin may rise abruptly causing hyperviscosity) to a haemoglobin about 8 to 9 g/dL.

• Antibiotics if febrile (ceftriaxone 50 to 80 mg/kg).

• After recovery: splenectomy after the first severe episode in children over 2 years, or after a second episode; chronic transfusion until age 2 as a bridge.

• Penicillin V prophylaxis 125 mg (under 3 years) or 250 mg (3 to 5 years) twice daily, pneumococcal, meningococcal and Haemophilus vaccination, parental education on spleen palpation.

• Hydroxyurea does not reliably prevent recurrence.