The mean life span of red cells in sickle cell anemia is only 20 days (one sixth of normal).Microvascular obstructions / Vaso-occlusion The red cell membrane damage and dehydration caused by repeated episodes of sickling produce a chronic hemolytic anemia.Ģ.Two major consequences arise from the sickling of red cells : Increased concentration of 2, 3-BPG in the red cells.The transit time for red cells through the microvasculature.The presence of hemoglobins other than HbS.Many variables influence the sickling of red cells in vivo.Over time, this cumulative damage creates irreversibly sickled cells, which are rapidly hemolyzed. Vaso-obstruction affecting different organs and tissues results in infarcts which may be of 2 types.Vaso-occlusion does not correlate with the number of irreversibly sickled cells and therefore appears to result from factors such as infection, inflammation, dehydration, and acidosis that enhance the sickling of reversibly sickled cells.Second, red cell sickling produces widespread microvascular obstructions, which result in ischemic tissue damage and pain crises. – Microinfarcts affecting particularly the abdomen, chest, back and joints and are the cause of recurrent painful crises in SS.
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– Macroinfarcts involving most commonly the spleen (splenic sequestration, autosplenectomy), bone marrow (pains), bones (aseptic necrosis, osteomyelitis), lungs (pulmonary infections), kidneys (renal cortical necrosis), CNS (stroke), retina (damage) and skin (ulcers), and result in anatomic and functional damage to these organs. #Simplemind map for sickle cell anemia skin – The increased breakdown of heme to bilirubin The anatomic alterations in sickle cell anemia stem from. There is a compensatory hyperplasia of erythroid progenitors in the marrow.Both the anemia and the vascular stasis lead to hypoxia-induced fatty changes in the heart, liver, and renal tubules.In peripheral smears, elongated, spindled, or boat-shaped irreversibly sickled red cells are evident.– Microvascular obstructions, which provoke tissue ischemia and infarction. The cellular proliferation in the marrow often causes bone resorption and secondary new bone formation, resulting in prominent cheekbones and changes in the skull resembling a “crewcut” in radiographs. In children there is moderate splenomegaly (splenic weight up to 500 g) due to red pulp congestion caused by entrapment of sickled red cells.Extramedullary hematopoiesis may appear in the liver and spleen. However, the chronic splenic erythrostasis produces hypoxic damage and infarcts, which over time reduce the spleen to a useless nubbin of fibrous tissue.
This process, referred to as autosplenectomy, is complete by adulthood. Vascular congestion, thrombosis, and infarction can affect any organ, including the bones, liver, kidney, retina, brain, lung, and skin.
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#Simplemind map for sickle cell anemia free.#Simplemind map for sickle cell anemia skin.
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