Splenic Sequestration

1. Splenic Sequestration Tessa Bandhan

2. Question 1 • A 3 year old girl known to have sickle cell disease (Hb SS) presents to the Emergency Room with a 2 day history of weakness and abdominal pain and recent onset of fever. Examination reveals HR140, RR40 T37.5C, pallor and tender splenomegaly. CBC show Hb4, WBC20, Plt 120. A diagnosis of acute splenic sequestration crisis is made.

3. What is the best treatment? • Total splenectomy • Observation • Partial splenectomy • pRBC transfusion • Administration of antibiotics

4. What is the best treatment? • Total splenectomy • Observation • Partial splenectomy • pRBC transfusion • Administration of antibiotics

5. Splenic Sequestration • Splenic sequestration is a complication of sickle cell anemia. • It occurs when red blood cells sickle within the spleen causing trapping of the blood cells. This leads to a rapid and marked fall in hemoglobin concentration and an enlarging spleen.

6. Splenic sequestration crises can occur from 5 weeks to adulthood, but most first attacks occur between 3 months and 5 years. • SSC is often associated with viral or bacterial infection, including parvovirus B19.

7. Clinical manifestations: • Pallor • Sudden weakness • Tachycardia • Tachypnea • Abdominal fullness • There is a risk of hypovolemic shock and death. Splenic sequestration crisis is associated with a 10-15% mortality rate, occurring before transfusions can be given.

8. Treatment • Immediate treatment involves urgent RBC transfusion. This corrects the hypovolemia and causes mobilization of the blood cells trapped in the spleen. Splenomegaly begins to resolve and the hemoglobin level begins to rise (autotransfusion). The decrease in the size of the spleen and relief of abdominal pain may occur within hours to days after the transfusion.

9. After the acute event has resolved, subsequent management may follow one of three courses. • Observation – used only in situations where the first crisis was mild and did not require transfusion. This is infrequently done due to the high risk of recurrence and significant mortality.

10. Chronic transfusion – administration of repeated blood transfusions over a prolonged period may reduce the risk of acute sequestration. • Splenectomy - Sequestration is recurrent in 50% of survivors; as a result, splenectomy is usually recommended after the first acute event.

11. Question 2 • An 8 year old boy with HbSC disease presents to the ER with pallor, weakness and abdominal pain. The differential diagnosis includes acute splenic sequestration crisis and aplastic crisis.

12. What laboratory test would best identify his condition? • ESR • Hemoglobin level • WBC • Platelet count • Reticulocyte count

13. Question 2 • What laboratory test would best identify his condition? • ESR • Hemoglobin level • WBC • Platelet count • Reticulocyte count

14. The criteria for diagnosis of splenic sequestration crisis include: • Decrease of at least 2g/dL from the steady-state Hb concentration • Evidence of increased erythropoiesis such as markedly elevated reticulocyte count • Acutely enlarging spleen

15. Aplastic anemia is as an acute illness with a Hb below the patient’s baseline with a decreased reticulocyte count. It is usually associated with parvovirus B19 infection.

16. Resources • Splenic sequestration and transient aplastic crises. Winfred C. Wang, MD. St Judes Children’s Research Hospital. • Splenic complications of sickle cell anemia and the role of splenectomy. Al-Salem, Ahmed. ISRN Hematology. Vol 2011, Article ID 864257