SICKLE CELL AND DEHYDRATION

Sickle Cell Anemia and Dehydration



Sickle Cell Anemia and Dehydration

Sickle cell anemia is a genetic disease responsible for abnormal hemoglobin in red blood cells. Hemoglobin is responsible for transporting oxygen to tissues. The abnormal hemoglobin (hemoglobin S), under certain conditions (cold, fever, dehydration, etc), Will make red blood cells rigid, they lose their normal ability to deform to pass through the tiny blood vessels (Frenette, Atweh, 2007).

No cure is achieved easily for sickle cell anemia. However, there are treatments to relieve symptoms and to address complications. The goals of treating sickle cell anemia are to relieve pain, prevent infections, eye injuries and stroke, and manage complications that may arise (Frenette, Atweh, 2007).

Pathophysiology of sickle cell anemia

As a result of the mutation, when hemoglobin is deoxygenated, it undergoes spontaneous polymerization to form a crystalline gel. Each polymer consists of 14 longitudinal beams deoxy-Hb that is arranged as a body tactoids, with insoluble and rigid cylindrical structure. Because of these polymers, it breaks the red cell cytoskeleton, adopting the characteristic shape of sickle cell (He, Russell, 2002).

Although the phenomenon of sickle cell is reversible, between 5 and 50% of sickle erythrocytes fail to recover its original shape, being eliminated by the mononuclear phagocyte system. On the other hand, erythrocytes have altered a great decrease in cell volume and a large increase in hemoglobin concentration. This is because the deoxy-Hb induces alterations of the erythrocyte membrane (change in the composition and distribution of phospholipids in the bi layer) that are translated by a profound dehydration. In addition, sickle cells exhibit a greater tendency to adhere to vascular endothelium by promoting the formation of micro thrombi and peripheral vascular occlusions (He, Russell, 2002).

Interestingly, hemoglobin S may interact with other forms of hemoglobin, in particular with fetal hemoglobin (HbF). In the presence of this form of hemoglobin, it reduces the degree of polymerization of HbS, which explains why sickle cell anemia is never presented during the neonatal period or hereditary persistence of fetal hemoglobin (He, Russell, 2002).

Signs and Symptoms

The abnormal hemoglobin will lead to several consequences:

Red blood cells are fragile and are destroyed by excess: the hemoglobin is low, defining chronic anemia. Children are always anemic, but usually adapt very well. The only visible signs may be fatigue and yellow eyes (as in breaking the red blood cells release a yellow pigment, bilirubin).

Red blood cells are rigid: they will form the caps and ...