Etiology

Rapid, severe bleeding leads to anemia from blood loss, hypovolemia (decreased volume of circulating blood), and, potentially, shock. A blood loss that leads to anemia may result from severe trauma to the blood vessels and massive hemorrhage or the blood loss may be more gradual, as from a small, bleeding peptic ulcer that causes a chronic blood loss.

Iron or folic acid may not be well absorbed in people who have an intestinal malabsorption syndrome.

Hemolytic anemias, in which red cells are destroyed prematurely in the body, have many causes. Hemolytic anemia can be a result of genetic defects that affect cell structure, causing the cells to disintegrate quickly. Some of the hemolytic anemias, such as thalassemia, are inherited, whereas others are acquired when erythrocytes are exposed to poisonous agents, such as chemicals or certain bacterial toxins.

Immune reactions can cause blood cell hemolysis (destruction of red cells). The presence of toxins in the blood, infections such as malaria, transfusion reactions, and changes in blood chemistry may cause red cell hemolysis. Blood incompatibility in the newborn (erythroblastosis fetalis) is another cause.

Pathophysiology

Hemolytic anemias associated with excessive destruction of RBCs are quite rare. When red cells are not normal, they break up easily or are destroyed by the body more quickly than are normal red cells. This RBC destruction causes the anemia.

Anemia occurs in end-stage renal disease patients when there is a deficiency of production of erythropoietin, a substance necessary to stimulate the production of RBCs in the bone marrow. This problem is usually corrected by the administration of epoetin alfa (Epogen), which stimulates red cell production (Singh, 2006). Oxygen transport depends on the number and condition of the red cells and the amount of hemoglobin they contain.

Diagnosis

The microscopic appearance of the red cells in a film of blood that has been spread over a slide (a peripheral smear) gives information about abnormalities in size, shape, and color of erythrocytes circulating in the patient’s bloodstream. The complete blood count (CBC) and differential cell count results are used to diagnose the presence of anemia. Measuring the quantity of hemoglobin tells whether the cells have sufficient amounts of hemoglobin to carry adequate oxygen to the body.

The prefix normo- refers to normal; the suffix -cyte refers to cells; the suffix -chrom refers to color; and the suffix –ic means “having the quality of” or “characterized by.” Thus a normocytic, normochromic anemia is characterized by cells that are normal in size and color, but that have a deficiency in the number of RBCs and a low hematocrit. This type of anemia usually occurs as a result of sudden blood loss.

A hypochromic, microcytic anemia is characterized by decreased levels of hemoglobin (not enough color) and small (micro) cells. This type of anemia is typical of an iron deficiency anemia.

Treatment

Anemia from chronic, slow blood loss is treated by correcting the underlying problem and then building replacement blood cells. Anemia caused by inadequate iron, folic acid, or protein intake is managed with oral iron supplements, vitamins, and diet adjustment. If the anemia is serious, blood transfusions may be given, or iron supplementation may be administered intravenously (IV) with iron dextran (Imferon), sodium ferrous gluconate, or iron sucrose.

Etiology

Sickle cell trait, in which only about 50% of an individual’s total hemoglobin is affected, is present in about 10% of the African American population of the United States. The trait is heterozygous, meaning that the person has an inherited gene for the trait from one parent only. People with the heterozygous trait for sickle cell are carriers; they can transmit the gene to their children even when they themselves do not show signs of the disease. Therefore, genetic counseling and adequate screening for early detection of the disease are considered extremely important to control sickle cell anemia. In the United States, many patients with sickle cell anemia live into their mid-40s. The most common cause of death is acute chest syndrome, where damage occurs to the lungs.

Pathophysiology

When the patient with sickle cell disease experiences lower oxygenation than normal, the defective S hemoglobin forms clumps in the red cells, causing them to assume a sickle shape, blocking blood vessels, breaking apart, and forming thrombi that cause organ damage. Sickle cells are destroyed by the body very quickly, causing anemia.

Sickle cell trait occurs in people who have only one gene, rather than a pair of genes, for sickle cell anemia. They usually do not have problems with cells assuming a sickle shape unless they experience severe oxygen deficiency.

Signs and Symptoms

Diagnosis

A peripheral blood smear can show sickled cells. The sickling test, which exposes RBCs to a deoxygenating agent, is diagnostic. Hemoglobin electrophoresis identifies the presence of abnormal hemoglobin. During crisis, there will be elevations of serum bilirubin because of the hemolysis of the abnormal red cells. Bone and joint abnormalities are revealed by skeletal x-rays.

Treatment

There is no cure or specific treatment for sickle cell anemia; treatment is primarily symptomatic and preventive. Patients should be taking folic acid regularly and eating a diet with sufficient protein to help build red cells. Infection is to be avoided, and the patient should receive all recommended immunizations against influenza, hepatitis A and B, pneumonia, tetanus, and the like. Adequate intake of fluid on a daily basis is important to keep the blood as fluid as possible. Alcohol and recreational drugs are to be avoided as they can cause complications. Quick attention for illness should be sought.

The drug hydroxyurea (Hydrea) has been found to reduce the frequency of sickling episodes. Patients on this drug have shown a 50% decrease in the number of hospitalizations for crisis (Platt, 2008). Sodium cromoglycate given by inhalation or via nasal route has been shown to significantly reduce the percentage of cells that sickle in venous blood (Bizumukama et al., 2009). If a crisis occurs, the patient may be treated at home with bed rest, adequate fluid intake, and analgesics. Pain control is important during a crisis. Narcotic analgesia with morphine is administered on a continuous basis, usually by patient-controlled analgesia pump. If the patient’s hemoglobin drops considerably or his condition suddenly deteriorates, he is hospitalized, given oxygen, and transfused with packed red cells; in addition, IV fluids are given. An attempt is made to mobilize the sickled cells and to prevent damage to major organs. Infection is treated with appropriate antibiotics.

BMT is the only available treatment that can cure some patients. The scarcity of donors, the cost, and the risks involved greatly limit the use of this option. Gene therapy is offering hope for future treatment of sickle cell disease.

Nursing Management

Nursing care is aimed at relieving the symptoms from complications of the disease and minimizing organ damage. Patients are taught to avoid high altitudes, vigorous exercise, and iced liquids. Patients are to maintain adequate fluid intake, refrain from smoking, and obtain treatment for infections promptly. Adequate rest is important as patients with sickle cell anemia experience fatigue. Assessment for adequate pain relief is a top priority (Arnold & Besa, 2010). Intake and output will be monitored to prevent overloading the patient with fluid. Oxygen therapy is instituted if the patient is hypoxic (oxygen therapy helps prevent further cellular damage).

Etiology

Leukemia is a cancer, and as with other types of cancers, the exact cause of leukemia is not known. There are factors considered to be closely linked with the development of leukemia. Exposure to ionizing radiation in relatively large doses is one such factor. Another is exposure to certain chemicals, such as benzene, that are toxic to bone marrow. Benzene is an ingredient in lead-free gasoline, and the incidence of leukemia has risen since lead-free gasoline has been in use. The amount of exposure to benzene and other chemicals that causes bone marrow suppression is unknown, and this amount possibly varies among individuals. The point is to be careful about breathing gasoline fumes and using household chemicals and pesticides. The third factor is the retrovirus known as human T-lymphotropic virus 1 (HTLV-1), which causes human T-cell leukemia. People with an abnormal number of chromosomes and chromosomal translocations are at a greater risk for developing acute lymphocytic leukemia. About 90% of patients with chronic myelogenous leukemia have the Philadelphia chromosome.