Anemia, sickle cell
Life-threatening disorderDescription
Congenital hemolytic disease that results from a defective hemoglobin (Hb) molecule (HbS), causing red blood cells (RBCs) to become sickle shaped
Sickle-shaped cells impairing circulation, resulting in chronic ill health (fatigue, dyspnea on exertion, swollen joints), periodic crises, long-term complications, and premature death
Autosomal recessive disorder
No universal cure (Bone marrow transplantation offers a cure; however, the procedure is risky, few patients have matched donors, and it’s costly.)
Most common in tropical Africans and in people of African descent
Abnormal gene present in about 1 in 12 blacks; if two such carriers have offspring, each child has 1-in-4 chance of developing disease
Occurs in 1 in every 500 blacks in the United States alone
Also occurs in Puerto Rico, Turkey, India, the Middle East, and the Mediterranean area
Pathophysiology
Abnormal HbS found in the patient’s RBCs becomes insoluble whenever hypoxia occurs.
RBCs become rigid, rough, and elongated, forming a crescent or sickle shape.
Sickling may produce hemolysis (cell destruction).
Altered cells accumulate in capillaries and smaller blood vessels, making the blood more viscous.
Normal circulation is impaired, causing pain, tissue infarctions, and swelling.
Causes
Homozygous inheritance of the HbS-producing gene (defective Hb gene from each parent)
Assessment findings
Signs and symptoms usually not developing until after age 6 months
History of chronic fatigue, unexplained dyspnea, or dyspnea on exertion
Joint swelling
Aching bones
Chest pain
Ischemic leg ulcers
Increased susceptibility to infection
Pulmonary infarctions and cardiomegaly
Jaundice or pallor
May appear small in stature for age
Delayed growth and puberty
Spiderlike body build (narrow shoulders and hips, long extremities, curved spine, and barrel chest) in adult
Tachycardia
Hepatomegaly and, in children, splenomegaly
Systolic and diastolic murmurs
Sleepiness with difficulty awakening
Hematuria
Pale lips, tongue, palms, and nail beds
Body temperature over 104° F (40° C) or a temperature of 100° F (37.8° C) persisting for 2 or more days
In painful crisis
Most common crisis and the hallmark of the disease, usually appearing periodically after age 5, characterized by severe abdominal, thoracic, muscle, or bone pain and, possibly, increased jaundice, dark urine, and a low-grade fever
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