Anemia – Hemolytic Anemia
Anemia is defined as a below normal plasma hemoglobin concentration resulting from a decreased number of circulating red blood cells or an abnormally low total hemoglobin content per unit of blood volume. anemia can be caused by chronic blood loss, bone marrow abnormalities, increased hemolysis, infections, malignancy, endocrine deficiencies, renal failure, and a number of other disease states. Anemia can be at least temporarily corrected by transfusion of whole blood. In addition, nutritional anemias are caused by dietary deficiencies of substances such as iron, folic acid, and vitamin B12 (cyanocobalamin)that are necessary for normal erythropoiesis.
SIGNS OF ANEMIA:
Pallor, breathlessness, tiredness, pica.
In hemolytic anemia cells become fragile, so they rupture easily as they go through the capillaries, especially through the spleen. The life span of the fragile red blood cells is so short that the cells are destroyed faster than they can be formed and serious anemia can result. In hereditary spherocytosis, the red cells are very small and spherical rather than being biconcave discs. On passing through the splenic pulp and some other tight vascular beds, they are easily ruptured by even slight compression. In erythroblastosis fetalis, Rh-positive red blood cells in the fetus are attacked by antibodies from an Rh-negative mother. These antibodies make the Rh-positive cells fragile, leading to rapid rupture and causing the child to be born with serious anemia. The extremely rapid formation of new red blood cells to make up for the destroyed cells in erythroblastosis fetalis causes a large number of early blast forms of red cells to be released from the bone marrow into the blood. In sickle cell anemia, which is present in 0. 3 to 1. 0 percent of west African and American blacks, the cells have an abnormal type of hemoglobin called hemoglobin. Hemoglobin S is caused by point mutation in both genes coding for beta chain, which results in decreased solubility in deoxy form. Sickel cell anemia is a homozygous, recessive disorder. Sickel cell anemia is characterized by life long episodes of pain (crises), chronic hemolytic anemia with associated hyperbilirubinemia and increased susceptibilty to infection,usually beginning in early childhood. when this hemoglobin is exposed to low concentration of oxygen, it precipitates into long crystals inside the red blood cell. These crystals elongate the cell and give it the appearance of a sickle rather than a biconcave disc and occulate a blood vessel.