Overview
Definition:
Sickle splenic sequestration is a life-threatening complication of sickle cell disease (SCD) characterized by rapid trapping of red blood cells in the spleen, leading to profound anemia, hypovolemia, and shock
It occurs most commonly in young children with SCD, typically between 6 months and 3 years of age, due to the spleen’s susceptibility to vaso-occlusion and infarction in early childhood before autosplenectomy occurs.
Epidemiology:
It is a common cause of severe anemia in infants and young children with sickle cell anemia (HbSS) and sickle-beta thalassemia
Incidence varies, but it is estimated to affect up to 50% of children with SCD before age 5
Recurrence is common and increases morbidity and mortality.
Clinical Significance:
Prompt recognition and management are crucial to prevent hypovolemic shock and death
It is a medical emergency that requires immediate transfusion and supportive care
Understanding its pathophysiology, clinical presentation, and management is vital for pediatric residents preparing for DNB and NEET SS examinations.
Clinical Presentation
Symptoms:
Sudden onset of profound pallor
Marked weakness and lethargy
Irritability
Abdominal pain, particularly in the left upper quadrant
Enlarged, palpable spleen
Rapidly falling hemoglobin concentration
Signs of hypovolemic shock including tachycardia, hypotension, tachypnea, and decreased urine output.
Signs:
Vital sign abnormalities: Tachycardia disproportionate to fever
Hypotension in later stages
Pale conjunctivae and mucous membranes
Enlarged, firm, and often tender spleen palpable in the left upper quadrant
Signs of shock: cool, clammy skin
delayed capillary refill
altered mental status.
Diagnostic Criteria:
Diagnosis is primarily clinical, supported by laboratory findings
Key features include: presence of sickle cell disease or trait
sudden drop in hemoglobin level (often >2 g/dL from baseline)
enlarged spleen palpable below the costal margin
clinical signs of hypovolemia or shock
and absence of other explanations for acute anemia.
Diagnostic Approach
History Taking:
Detailed history of sickle cell disease diagnosis, prior splenic events, recent illnesses, and pain
Assess the speed of onset of symptoms
Note any history of transfusion or splenectomy
Screen for family history of sickle cell disease
Red flags: rapid decline in consciousness, severe pallor, absent pulses.
Physical Examination:
Perform a thorough abdominal examination, focusing on spleen size and tenderness
Assess vital signs meticulously for signs of hypovolemia and shock
Examine skin for pallor and signs of dehydration
Assess neurological status for lethargy or altered mental state.
Investigations:
Complete blood count (CBC) with differential and reticulocyte count to assess the degree of anemia and bone marrow response
Peripheral blood smear to confirm presence of sickle cells
Serum electrolytes, renal function tests (BUN, creatinine), and liver function tests to assess organ perfusion
Blood type and crossmatch for urgent transfusion
Chest X-ray may be considered to rule out concurrent pneumonia
Ultrasound of the abdomen may confirm splenic enlargement and assess spleen size if clinical examination is difficult.
Differential Diagnosis:
Other causes of acute anemia and shock in children with SCD: Aplastic crisis (due to parvovirus B19 infection, characterized by absent reticulocytes and normal or small spleen)
Hemolytic crisis (characterized by increased reticulocyte count and hyperbilirubinemia)
Acute chest syndrome
Sepsis
Gastrointestinal bleeding.
Management
Initial Management:
Immediate stabilization is paramount
Place intravenous lines for fluid resuscitation and blood product administration
Monitor vital signs continuously
Administer oxygen if hypoxic
Maintain adequate hydration with intravenous fluids (e.g., normal saline or Ringer's lactate).
Medical Management:
Exchange transfusion or simple red blood cell transfusion is the mainstay of treatment
The goal is to rapidly increase hemoglobin and reduce the percentage of sickled cells
Transfuse packed red blood cells to raise hemoglobin to approximately 9-10 g/dL and reduce sickling
In severe cases with hypovolemic shock, exchange transfusion may be considered to lower the hematocrit and improve oxygen-carrying capacity
Monitor for signs of transfusion reactions.
Surgical Management:
Splenectomy is generally avoided in the acute phase due to high risk of overwhelming postsplenectomy infection (OPSI)
It may be considered in cases of recurrent, life-threatening splenic sequestration episodes or when conservative management fails and there is no alternative
Prophylactic measures for OPSI are essential post-splenectomy.
Supportive Care:
Pain management with analgesics
Strict fluid balance monitoring
Close monitoring of vital signs, urine output, and mental status
Nutritional support
Prophylactic antibiotics if sepsis is suspected
Educate parents on recognition of early symptoms for prompt intervention.
Complications
Early Complications:
Hypovolemic shock
organ damage due to severe hypoxia and hypoperfusion (e.g., acute kidney injury, hepatic dysfunction)
death.
Late Complications:
Recurrent splenic sequestration episodes
increased susceptibility to infection due to functional asplenia (even without splenectomy)
chronic anemia
growth and developmental delay.
Prevention Strategies:
Regular hydroxyurea therapy to increase fetal hemoglobin (HbF) levels, which reduces sickling and frequency of vaso-occlusive events, including splenic sequestration
Early diagnosis and initiation of penicillin prophylaxis in infants with SCD to prevent overwhelming infections
Education of parents and caregivers on recognizing early signs of splenic sequestration and seeking immediate medical attention
Consider prophylactic transfusion in children with frequent severe sequestration events
Transfusions are generally recommended for children with severe or recurrent splenic sequestration episodes to prevent further crises and potential splenectomy.
Prognosis
Factors Affecting Prognosis:
Promptness of diagnosis and intervention
severity of anemia and shock
presence of co-existing infections or organ damage
effectiveness of transfusion therapy
recurrent nature of sequestration.
Outcomes:
With prompt and appropriate management, most children survive splenic sequestration
However, recurrence is common, and repeated episodes can lead to functional asplenia and increased risk of infection
Long-term outcomes are influenced by the overall management of sickle cell disease.
Follow Up:
Close follow-up with a pediatric hematologist is essential
Regular monitoring of CBC, reticulocyte count, and growth parameters
Continue hydroxyurea therapy as indicated
Reinforce penicillin prophylaxis and pneumococcal, meningococcal, and Haemophilus influenzae type b (Hib) vaccinations
Educate families on ongoing SCD management and recognition of complications.
Key Points
Exam Focus:
Sickle splenic sequestration is a pediatric emergency in SCD, common between 6 months-3 years
Characterized by rapid anemia and splenomegaly
Management is urgent transfusion to reverse hypovolemia
Exchange transfusion may be indicated for shock
Prophylaxis includes hydroxyurea, penicillin, and vaccinations
Recurrence is common.
Clinical Pearls:
Always consider splenic sequestration in any child with SCD presenting with acute pallor and enlarged spleen
A rapidly falling hemoglobin level in a child with SCD and splenomegaly is highly suggestive
Transfusion is life-saving
do not delay
Assess vital signs for shock carefully
Differentiate from aplastic crisis (normal spleen, absent reticulocytes).
Common Mistakes:
Delaying transfusion due to concerns about fluid overload
misdiagnosing as a simple viral illness
failing to recognize the severity of hypovolemia and shock
not considering exchange transfusion in severe cases
neglecting to counsel on recurrence and long-term prevention strategies.