Sickle Cell Anemia, According to the World Health Organization, is an inherited anemia in which the RBCs (Red Blood Cells) have a specific mutation that makes the hemoglobin in the red cells very sensitive to oxygen changes. It is characterized by a modification in the shape of the red blood cell from a smooth, donut-shape into a crescent or half moon shape any time a decrease in the oxygen tension is sensed. This condition leads to shortened red blood cell survival, causing the anemia.
Normal red cells live about 120 days. Sickled cells survive only about 15 to 20 days, an 80 to 90 percent decrease in cell survival. Modified cells lack plasticity and block small blood vessels, impairing blood flow. The result is congestion, clumping, and clotting.
Sickle cell anemia is inherited from both parents having the sickle cell trait. If only one parent has the hemoglobin S gene (the sickle cell trait) and the other parent has a normal hemoglobin gene, then the child only becomes an asymptomatic carrier who only possess the sickle-cell trait. In the United States, sickle cell anemia is most often found in those of African or Eastern Mediterranean origin. Worldwide, many persons residing in Asia, the Caribbean, the Middle East, and Central America are affected. Nearly 10 percent of African-Americans have the sickle cell trait; 1 out of every 400 African-American infants born has inherited the two sets of abnormal genes necessary to have the disease.
Common symptoms include abdominal and bone pain, fatigue, fever, delayed growth and puberty, breathlessness, paleness, rapid heart rate, jaundice, chest pain, frequent urination and excessive thirst, ulcers in the legs and priaprism. To best diagnose this disease is to do a blood smear that shows sickle-shaped RBCs in circulation. To determine the presence of hemoglobin S, hemoglobin electrophoresis is done.
Symptoms do not appear in infants until after the age of 6 months, because up to that age the infant is using hemoglobin manufactured during fetal life, which is not affected by the sickling process. The sickling changes are a daily occurrence. The rapid return of the oxygen level to normal returns the cells to their normal shape for the most part. Sickle cell crisis occurs when the sickling process cannot be reversed and the problem continues unstopped. Pneumonia with hypoxia, exposure to cold, diabetic acidosis, and severe infection are some examples of factors that decrease oxygenation leading to the development of a sickle cell crisis. These can affect the bones of the back, long bones and the chest. Repeated crisis and infarctions lead to chronic manifestations such as hand-foot syndrome, an unequal growth of fingers and toes from infarction of the small bones in the hands and feet.
Prevention and Treatments
To prevent the crisis from occurring, always take precautionary measures to prevent oxygen loss, infection, and dehydration which trigger a sickling.
According to Pillitteri (Maternal and Child Health Nursing, p.1397), the child in sickle-cell crisis has three primary needs: pain relief, adequate hydration and adequate oxygenation to halt the crisis and prevent further sickling.
It is important to treat the pain. Non-narcotic medications may be effective, but some patients will need large doses of narcotics. There is no known cure for sickle cell anemia but continual patient education to prevent crisis and supportive care when crisis occurs is the aim of the treatment. Some patients may be placed on low-dose oral penicillin to help prevent infections, decreasing the risk of crisis.
It is best to call a health care provider during painful crisis or any symptoms of infection such as fever, body aches, headache, and fatigue. Overall, genetic counseling is important to prevent passing on the trait or disease to children.