NCLEX RN Practice Question # 778
NCLEX Examination.
Practice Question # 778.
Nclex examination.
Sickle cell anemia:
A type of congenital hemolytic anemia (shortened RBC survival and inability of bone marrow to compensate for decreased RBC life span), sickle cell anemia occurs mainly in African-Americans. It results from a defective Hb molecule (HbS), which causes RBCs to roughen and become sickle shaped and more fragile.
Renegade RBCs:
The abnormal RBCs impair circulation, resulting in chronic ill health, periodic crises, long-term complications, and premature death.
What causes it:
Sickle cell anemia may stem from homozygous inheritance of the HbS–producing gene, which causes the amino acid valine to replace glutamic acid in the Hb beta chain. (See Understanding sickle cell trait.)
Pathophysiology:
Blood vessel obstruction by rigid, tangled RBCs causes tissue oxygen starvation and possible necrosis. These conditions, in turn, lead to painful vaso-occlusive crisis, a hallmark of the disease. Bone marrow depression results in aplastic (megaloblastic) crisis.