Splenic sequestration is a medical emergency where blood cells become trapped and accumulate within the spleen, causing it to rapidly enlarge. This leads to a sudden and significant drop in circulating red blood cells, which can be life-threatening and requires immediate medical attention.
The Spleen’s Function
The spleen, a fist-sized organ located in the upper left abdomen beneath the rib cage, is part of the lymphatic system. It is involved in blood filtration and immune responses. One primary function is to filter old, damaged, or abnormal red blood cells from the bloodstream.
Beyond filtration, the spleen acts as a reservoir, storing blood cells and platelets for times of need, such as severe blood loss. It also contributes to the immune system by producing white blood cells and antibodies that defend the body against infections. The spleen helps recycle iron from old red blood cells, returning it to the bone marrow for new hemoglobin production.
How Splenic Sequestration Develops
Splenic sequestration develops when blood cells, particularly red blood cells, become trapped and pool within an enlarged spleen. This occurs because blood flows into the spleen but struggles to exit, leading to a rapid expansion of the organ. The underlying mechanism involves conditions that affect red blood cell shape and flexibility, preventing them from passing through the narrow blood vessels within the spleen.
This condition is commonly associated with inherited blood disorders such as sickle cell disease, where red blood cells are abnormally shaped and rigid. These stiff, sickled cells can obstruct blood flow within the spleen, causing blood to accumulate and swell. Thalassemia and other hemolytic anemias can also predispose individuals to splenic sequestration. The pooling of blood reduces circulating volume, leading to severe anemia and decreased overall blood volume. This rapid reduction can result in insufficient oxygen delivery to the body’s tissues and organs.
Identifying Symptoms
Recognizing splenic sequestration symptoms is important for prompt intervention, as the condition can develop rapidly. One noticeable sign is sudden pallor, where skin, lips, and fingernails appear unusually pale. Individuals may also experience pronounced fatigue and weakness, often accompanied by increased irritability or unusual sleepiness.
Rapid breathing and a fast heart rate are common indicators as the body attempts to compensate for reduced oxygen. Abdominal pain, especially on the left side, is frequently reported, and the spleen may feel noticeably enlarged, firm, or tender to the touch. These symptoms collectively signal a medical event requiring immediate evaluation.
Diagnosis and Treatment Approaches
Medical professionals diagnose splenic sequestration through a combination of clinical assessment and specific tests. A physical examination typically reveals an enlarged and often tender spleen, which can be felt below the rib cage. Blood tests, particularly a complete blood count (CBC), are performed to confirm the diagnosis. These tests usually show a sudden and significant drop in hemoglobin levels, indicating severe anemia, and may also reveal a decrease in platelets. Sometimes, an ultrasound of the abdomen is used to assess spleen size and confirm the pooling of blood, especially if the spleen is not easily palpable.
Immediate medical intervention for splenic sequestration focuses on stabilizing the individual and restoring blood volume. Fluid resuscitation, often administered intravenously, helps to replenish lost blood volume and maintain circulation. Blood transfusions are a primary treatment, providing healthy red blood cells to replace those trapped in the spleen, which helps improve oxygen delivery to the body. These transfusions can help the spleen release trapped cells and gradually return to its normal size.
For individuals with recurrent episodes of splenic sequestration, surgical removal of the spleen (splenectomy) may be considered as a long-term strategy. While splenectomy prevents future sequestration crises, it increases susceptibility to certain infections, as the spleen plays a role in the immune system. Therefore, individuals undergoing splenectomy typically receive ongoing antibiotic prophylaxis and specific vaccinations to mitigate infection risks.