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Sickle Cell Anemia - End Stage Organ Disease CHRONIC RENAL FAILURE Chronic renal failure in sickle cell disease is associated with endstage renal disease due to one or a combination of the sickle cell nephropathies discussed above. Chronic renal failure occurs in a small percentage of patients with sickling disorders, and its prevalence in sickle cell disease appears to be greater than among the general AfricanAmerican population. When it is associated with metabolic acidosis without significant hyperkalemia and with BUN levels less than 80.0 mg/mL and creatinine less than 4.0 mg/mL, patients can usually be managed with conservative measures, including oral sodium bicarbonate, oral phosphate binders such as Amphojel Ò , and a lowprotein diet. In this instance, BUN, creatinine, electrolytes, and acidbase balance should be carefully monitored. Drugs with altered pharmacokinetics in the presence of renal failure should either be avoided or have dosages appropriately modified. As renal failure progresses, the patient should be referred for dialysis or possible renal transplantation.Sickle cell disease is not a contraindication for hemodialysis or renal transplantation. Sickle cell disease patients who have received renal homografts may experience more frequent pain crises due to increased hematocrit driven by erythropoietin produced by the graft kidney. Recurrent sickle cell nephropathy in the transplanted kidney has been reported. In some patients, the increased anemia found with chronic renal failure causes cardiopulmonary complications and necessitates a chronic transfusion program. Treatment with recombinant erythropoietin (EPO) improves the anemia of renal failure in nonsickle cell disease patients; however, there are no large studies of the use of EPO in Hb SS patients with renal failure. The experience with a few of these patients so far indicates that large doses of EPO (300 350 U/kg three times a week) may be required to induce a significant increase in hematocrit or to alleviate a transfusion requirement. HEMORRHAGIC STROKE Patients with intracranial hemorrhage (IH) may present with focal neurological deficits, severe headache, increased intracranial pressure, or coma. Immediate mortality is as high as 50 percent. This is a frequent cause of sudden unexpected death at home. In patients with endstage renal failure from sickle cell disease, IH is a common cause of death. Immediate CT or MRI scanning should demonstrate the hemorrhage. Lumbar puncture may be necessary to demonstrate the subarachnoid hemorrhage (blood in cerebrospinal fluid) in some patients. Because vasospasm in the area of hemorrhage can produce secondary cerebral infarction, immediate exchange transfusion is recommended. There are no data regarding the efficacy of longterm transfusion therapy for patients with IH. In those patients who are not uremic, arteriography is necessary to determine if a surgically correctable lesion (aneurysm) is present. |
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