congenital hypoplastic anemia


anemia

 [ah-ne´me-ah] a condition in which there is reduced delivery of oxygen to the tissues; it is not actually a disease but rather a symptom of any of numerous different disorders and other conditions. The World Health Organization has defined anemia as a hemoglobin concentration below 7.5 mmol/L (12 g/dL) in women and below 8.1 mmol/L (13 g/dL) in men. Peripheral blood smears from a patient with megaloblastic anemia (left) and from a normal subject (right), both at the same magnification. The smear from the patient shows variation in the size and shape of erythrocytes and the presence of macro-ovalocytes. From Goldman and Bennett, 2000.
Some types of anemia are named for the factors causing them: poor diet (nutritional anemia), excessive blood loss (hemorrhagic anemia), congenital defects of hemoglobin (hypochromic anemia), exposure to industrial poisons, diseases of the bone marrow (aplastic anemia and hypoplastic anemia), or any other disorder that upsets the balance between blood loss through bleeding or destruction of blood cells and production of blood cells. Anemias can also be classified according to the morphologic characteristics of the erythrocytes, such as size (microcytic, macrocytic, and normocytic anemias) and color or hemoglobin concentration (hypochromic anemia). A type called hypochromic microcytic anemia is characterized by very small erythrocytes that have low hemoglobin concentration and hence poor coloration. Data used to identify anemia types include the erythrocyte indices: (1) mean corpuscular volume (MCV), the average erythrocyte volume; (2) mean corpuscular hemoglobin (MCH), the average amount of hemoglobin per erythrocyte; and (3) mean corpuscular hemoglobin concentration (MCHC), the average concentration of hemoglobin in erythrocytes. adj., adj ane´mic.Symptoms. Mild degrees of anemia often cause only slight and vague symptoms, perhaps nothing more than easy fatigue or a lack of energy. As the condition progresses, more severe symptoms may be experienced, such as shortness of breath, pounding of the heart, and a rapid pulse; these are caused by the inability of anemic blood to supply the body tissues with enough oxygen. Pallor, particularly in the palms of the hands, the fingernails, and the conjunctiva (the lining of the eyelids), may also indicate anemia. In very advanced cases, swelling of the ankles and other evidence of heart failure may appear.Common Causes of Anemia. Loss of Blood (Hemorrhagic Anemia): If there is massive bleeding from a wound or other lesion, the body may lose enough blood to cause severe and acute anemia, which is often accompanied by shock. Immediate transfusions are generally required to replace the lost blood. Chronic blood loss, such as excessive menstrual flow, or slow loss of blood from an ulcer or cancer of the gastrointestinal tract, may also lead to anemia. These anemias disappear when the cause has been found and corrected. To help the blood replenish itself, the health care provider may prescribe medicines containing iron, which is necessary to build hemoglobin, and foods with high iron content, such as kidney and navy beans, liver, spinach, and whole wheat bread.
Dietary Deficiencies and Abnormalities of Red Blood Cell Production (Nutritional Anemia, Aplastic Anemia, and Hypoplastic Anemia): Anemia may develop if the diet does not provide enough iron, protein, vitamin B12, and other vitamins and minerals needed in the production of hemoglobin and the formation of erythrocytes. The combination of poor diet and chronic loss of blood makes for particular susceptibility to severe anemia. Anemias associated with folic acid deficiency are very common.
Excessive Destruction of Red Blood Cells (hemolytic anemia): Anemia may also develop related to hemolysis due to trauma, chemical agents or medications (toxic hemolytic anemia), infectious disease, isoimmune hemolytic reactions, autoimmune disorders, and the paroxysmal hemoglobinurias.Patient Care. Assessment of patients with some form of anemia will depend to some extent on the specific type of blood dyscrasia presented. In general, these patients do share some common problems requiring special assessment skills and interventions. Anemia can affect many different body systems (see table). Although pallor of the skin is a sign of anemia, it is not the most reliable sign; many other factors can affect complexion and skin color. Jaundice of the skin and sclera can occur as a result of hemolysis and the release of bilirubin into the blood stream, where it eventually finds its way into the skin and mucous membranes. (See also jaundice.) Bleeding under the skin and bruises in response to the slightest trauma often are present in anemic and leukemic patients. A bluish tint to the skin (cyanosis) can indicate hypoxia due to inadequate numbers of oxygen-bearing erythrocytes.
Activity intolerance is a common problem for patients with anemia. Physical activity increases demand for oxygen, but if there are not enough circulating erythrocytes to provide sufficient oxygen, patients become physically weak and unable to engage in normal physical activity without experiencing profound fatigue. This can result in some degree of deficit" >self-care deficit as the fatigue interferes with the patient's ability to carry on regular or enjoyable activities.acute posthemorrhagic anemia hemorrhagic anemia.aplastic anemia see aplastic anemia.autoimmune hemolytic anemia (AIHA) an acquired disorder characterized by hemolysis due to the production of autoantibodies against one's own red blood cell antigens.Blackfan-Diamond anemia congenital hypoplastic anemia (def. 1).congenital hypoplastic anemia idiopathic progressive anemia occurring in the first year of life, without leukopenia and thrombocytopenia; it is due to an isolated defect in erythropoiesis and is unresponsive to hematinics, requiring multiple blood transfusions to sustain life. For those responding to steroid therapy the prognosis is good. Called also Blackfan-Diamond anemia or syndrome, Diamond-Blackfan anemia or syndrome, and erythrogenesis imperfecta.Fanconi's syndrome (def. 1).Cooley's anemia tthalassemia major.deficiency anemia nutritional anemia.Diamond-Blackfan anemia congenital hypoplastic anemia (def. 1).drug-induced hemolytic anemia (drug-induced immune hemolytic anemia) a form of immune hemolytic anemia induced by the taking of drugs, involving one of four different mechanisms:
Immune complex problems: Ingestion of any of a large number of drugs is followed by immunization and the formation of a soluble drug–anti-drug complex that adsorbs nonspecifically to the erythrocyte surface.
Drug absorption: Drugs bind firmly to erythrocyte membrane proteins, inducing the formation of specific antibodies; the drug most commonly associated with this mechanism is penicillin.
Membrane modification: A nonimmunologic mechanism whereby the drug involved is able to modify erythrocytes so that plasma proteins can bind to the membrane.
Autoantibody formation: Methyldopa (Aldomet) induces the production of autoantibodies that recognize erythrocyte antigens and are serologically indistinguishable from those seen in patients with warm autoimmune hemolytic anemia.Fanconi's anemia (Fanconi's hypoplastic anemia) Fanconi's syndrome (def. 1).hemolytic anemia see hemolytic anemia.hemorrhagic anemia anemia caused by the sudden and acute loss of blood; called also acute posthemorrhagic anemia.hypochromic anemia anemia in which the decrease in hemoglobin is proportionately much greater than the decrease in number of erythrocytes.hypochromic microcytic anemia any anemia with microcytes that are hypochromic (reduced in size and in hemoglobin content); the most common type is iron deficiency anemia.hypoplastic anemia anemia due to incapacity of blood-forming organs.immune hemolytic anemia an acquired hemolytic anemia in which a hemolytic response is caused by isoantibodies or autoantibodies produced on exposure to drugs, toxins, or other antigens. See also anemia" >autoimmune hemolytic anemia, anemia" >drug-induced immune hemolytic anemia, and erythroblastosis fetalis.iron deficiency anemia a type of hypochromic microcytic anemia that results from the presence of greater demands on stored iron than can be met, usually because of chronic blood loss, dietary deficiency, or defective absorption; it is characterized by low or absent iron stores, low serum iron concentration, low transferrin saturation, elevated transferrin (total iron-binding capacity), and low hemoglobin concentration or hematocrit. Iron deficiency anemia is the most common nutritional disorder in the United States.macrocytic anemia anemia characterized by macrocytes" >macrocytes (erythrocytes much larger than normal).Mediterranean anemia thalassemia major.megaloblastic anemia any of various anemias characterized by the presence of megaloblasts" >megaloblasts in the bone marrow or blood; the most common type is pernicious anemia" >pernicious anemia.microangiopathic hemolytic anemia thrombotic thrombocytopenic purpura.microcytic anemia anemia characterized by microcytes" >microcytes (erythrocytes smaller than normal); see also hypochromic microcytic anemia and microcythemia.myelopathic anemia (myelophthisic anemia) leukoerythroblastosis.normochromic anemia that in which the hemoglobin content of the red blood cells is in the normal range.normocytic anemia anemia characterized by proportionate decrease in hemoglobin, packed red cell volume, and number of erythrocytes per cubic millimeter of blood.nutritional anemia anemia due to a deficiency of an essential substance in the diet, which may be caused by poor dietary intake or by malabsorption; called also deficiency anemia.pernicious anemia see pernicious anemia.sickle cell anemia see sickle cell anemia.sideroachrestic anemia (sideroblastic anemia) any of a heterogenous group of acquired and hereditary anemias with diverse clinical manifestations, commonly characterized by large numbers of sideroblasts in the bone marrow, ineffective erythropoiesis, variable proportions of hypochromic erythrocytes in the peripheral blood, and usually increased levels of tissue iron.spur cell anemia anemia in which the erythrocytes are acanthocytes (spur cells) and are destroyed prematurely, primarily in the spleen; it is an acquired form occurring in severe liver disease in which there is increased serum cholesterol and increased uptake of cholesterol into the erythrocyte membrane, causing the abnormal shape.

con·gen·i·tal hy·po·plas·tic a·ne·mi·a

[MIM*205900] a macrocytic anemia resulting from congenital hypoplasia of the bone marrow, which is grossly deficient in erythroid precursors whereas other elements are normal; anemia is progressive and severe, but leukocyte and platelet counts are normal or slightly reduced; survival of transfused erythrocytes is normal; minor congenital anomalies are found in some patients. Both autosomal dominant and recessive forms have been described, caused by mutation in the gene encoding ribosomal protein S19 (RBS19) on chromosomal 19q. Synonym(s): congenital nonregenerative anemia, Diamond-Blackfan anemia, Diamond-Blackfan syndrome, erythrogenesis imperfecta, familial hypoplastic anemia, pure red cell anemia
Congenital hypoplastic anaemia. An autosomal recessive [MIM 205900], occasionally consanguineous condition associated with pure red cell aplasia of early infancy onset with anaemia, pallor, failure to thrive; 30% of patients have minor physical abnormalities—e.g., short stature, thumb deformities, ocular changes
Management Transfusion, corticosteroids, bone marrow transplantation, growth factor therapy

con·gen·i·tal hy·po·plas·tic a·ne·mi·a

(kŏn-jen'i-tăl hī'pō-plas'tik ă-nē'mē-ă) Anemia resulting from congenital hypoplasia of the bone marrow, which is grossly deficient in erythroid precursors whereas other elements are normal; anemia is progressive and severe, but leukocyte and platelet counts are normal or slightly reduced; survival of transfused erythrocytes is normal.
Synonym(s): Diamond-Blackfan syndrome; congenital hypoplastic anaemia

anemia

(a-ne'me-a) [ ¹an- + -emia] A reduction in the mass of circulating red blood cells. People are considered anemic when their hemoglobin levels are more than two standard deviations below the mean level in their hospital's laboratory. The diagnosis of anemia is influenced by variables such as the patient's age (neonates are anemic at levels of hemoglobin that would be considered polycythemic in some adults), gender (men have higher hemoglobin levels than women), pregnancy status (hemodilution in pregnancy lowers measured hemoglobin), residential altitude, and ethnic or racial background. anemic (-ne'mik), adjectiveanemically (mi-k(a-)le)

Symptomatic anemia exists when hemoglobin content is less than that required to meet the oxygen-carrying demands of the body. If anemia develops slowly, however, there may be no functional impairment even though the hemoglobin is less than 7 g/100/dL of blood.

Anemia is not a disease but rather a symptom of other illnesses. It is classified on the basis of mean corpuscular volume as microcytic (80), normocytic (80–94), and macrocytic (> 94); on the basis of mean corpuscular hemoglobin as hypochromic (27), normochromic (27–32), and hyperchromic (> 32); and on the basis of etiological factors.

Etiology

Anemia may be caused by bleeding, e.g., from the gastrointestinal tract or the uterus; vitamin or mineral deficiencies, esp. vitamin B12, folate, or iron; decreases in red blood cell production, e.g., bone marrow suppression in kidney failure or bone marrow failure in myelodysplastic syndromes; increases in red blood cell destruction as in hemolysis due to sickle cell anemia; or increases in red blood cell sequestration by the spleen (as in portal hypertension), or administration of toxic drugs (as in cancer chemotherapy).

Symptoms

Anemic patients may experience weakness, fatigue, lightheadedness, breathlessness, palpitations, angina pectoris, and headache. Signs of anemia may include a rapid pulse or rapid breathing if blood loss occurs rapidly. The chronically anemic may have pale skin, mucous membranes, or nail beds and fissures at the corners of the mouth.

Treatment

Treatment of anemia must be specific for the cause. The prognosis for recovery from anemia is excellent if the underlying cause is treatable.

Anemia due to excessive blood loss: For acute blood loss, immediate measures should be taken to stop the bleeding, to restore blood volume by transfusion, and to combat shock. Chronic blood loss usually produces iron-deficiency anemia.

Anemia due to excessive blood cell destruction: The specific hemolytic disorder should be treated.

Anemia due to decreased blood cell formation: For deficiency states, replacement therapy is used to combat the specific deficiency, e.g., iron, vitamin B12, folic acid, ascorbic acid. For bone marrow disorders, if anemia is due to a toxic state, removal of the toxic agent may result in spontaneous recovery.

Anemia due to renal failure, cancer chemotherapy, HIV, and other chronic diseases: Erythropoietin injections are helpful.

Patient care

The patient is evaluated for signs and symptoms, and the results of laboratory studies are reviewed for evidence of inadequate erythropoiesis or premature erythrocyte destruction. Prescribed diagnostic studies are scheduled and carried out. Rest: The patient is evaluated for fatigue; care and activities are planned and regular rest periods are scheduled. Mouth care: The patient's mouth is inspected daily for glossitis, mouth lesions, or ulcers. A sponge stick is recommended for oral care, and alkaline mouthwashes are suggested if mouth ulcers are present. A dental consultation may be required. Diet: The patient is encouraged to eat small portions at frequent intervals. Mouth care is provided before meals. The nurse or a nutritionist provides counseling based on type of anemia. Medications: Health care professionals teach the patient about medication actions, desired effects, adverse reactions, and correct dosing and administration. Patient education: The cause of the anemia and the rationale for prescribed treatment are explained to the patient and family. Teaching should cover the prescribed rest and activity regimen, diet, prevention of infection, including the need for frequent temperature checks, and the continuing need for periodic blood testing and medical evaluation.

achlorhydric anemia

A hypochromic, microcytic anemia associated with a lack of free hydrochloric acid in gastric juice.APLASTIC ANEMIA: (×200)

aplastic anemia

Anemia caused by a severe decrease in the number of stem cells and/or white blood cell ancestors. See: illustration

Treatment

Many patients can be treated effectively with bone marrow transplantation or immunosuppressive drugs.

Patient care

The patient and family are educated about the cause and treatment of the illness. Measures to prevent infection are explained, and the importance of adequate rest is emphasized. In the acute phase, prescribed treatment is carried out; side effects of drugs and transfusions are explained, and a restful environment for the patient is ensured. If the patient's platelet count is low (less than 20,000/cu mm), the following steps are taken to prevent hemorrhage: avoiding parenteral injections, suggesting the use of an electric razor, use of humidifying oxygen to prevent dry mucous membranes, and promoting regular bowel movements with stool softeners and dietary measures. Pressure is applied to all venipuncture sites until bleeding has stopped, and bleeding is detected early by checking for occult blood in urine and stools and by assessing the skin for petechiae and ecchymoses. Standard precautions and careful handwashing (and protective isolation if necessary) are used; a diet high in vitamins and protein is provided, and meticulous oral and perianal care are provided. The patient is assessed for life-threatening hemorrhage, infection, adverse effects of drug therapy, or blood transfusion reactions. Throat, urine, and blood cultures are performed when indicated to identify infection. See: protective isolation

illustration

autoimmune hemolytic anemia

Abbreviation: AIHA
Anemia caused by antibodies produced by the patient's own immune system that destroy red blood cells. They are classified by the thermal properties of the antibody involved; the warm form is most common and may be associated with viral infections. Drug-induced hemolytic anemias are clinically indistinguishable from AIHA and are therefore classified with this disorder.

anemia of chronic inflammation

Inflammatory anemia.

congenital hemolytic anemia

Any of a group of inherited chronic diseases marked by disintegration of red blood cells, jaundice, splenomegaly, and gallstones. Hereditary spherocytosis is the most common of these hemolytic diseases. Other such anemias include congenital elliptocytosis, hereditary stomatocytosis, and hemolytic anemias caused by enzymatic defects of the red cell, of which glucose-6–phosphate dehydrogenase and pyruvate kinase deficiency are the most important. Synonym: hemolytic icterus; hemolytic jaundice See: glucose-6-phosphate dehydrogenase

congenital hypoplastic anemia

Diamond-Blackfan anemia.

Cooley anemia

See: Cooley anemia

deficiency anemia

Anemia due to lack of an essential ingredient such as iron or vitamins in the diet or the inability of the intestine to absorb them. Synonym: nutritional anemia

Diamond-Blackfan anemia

See: Diamond-Blackfan anemia

erythroblastic anemia

Anemia resulting from inheritance of a recessive trait responsible for interference with hemoglobin synthesis. Synonym: thalassemia major

folic acid deficiency anemia

Anemia resulting from a deficiency of folic acid. It is a cause of megaloblastic anemia and is common in patients with nutritional deficiencies, e.g., alcoholics, patients with malabsorption, and during hemolysis or pregnancy. Folate deficiency during pregnancy increases the risk of thrombocytopenia, hemorrhage, infection, and fetal neural tube defects.

Patient care

Fluid and electrolyte balance is monitored, particularly in the patient with severe diarrhea. The patient can obtain daily folic acid requirements by including an item from each food group in every meal; a list of foods rich in folic acid (green leafy vegetables, asparagus, broccoli, liver and other organ meats, milk, eggs, yeast, wheat germ, kidney beans, beef, potatoes, dried peas and beans, whole-grain cereals, nuts, bananas, cantaloupe, lemons, and strawberries) is provided. The rationale for replacement therapy is explained, and the patient is advised not to stop treatment until test results return to normal. Periods of rest and correct oral hygiene are encouraged.

hemolytic anemia

Anemia resulting from the destruction of erythrocytes by drugs, artificial heart valves, toxins, snake venom, infections, and antibodies. Drugs may either destroy the erythrocyte membrane directly or stimulate production of autoantibodies that lyse the erythrocytes. Children may develop hemolytic anemia in response to destruction of erythrocytes by viral and bacterial organisms. Artificial valves cause physical damage to the erythrocyte membrane during the circulation of blood through the heart. See: hemolytic uremic syndrome

hyperchromic anemia

Anemia in which mean corpuscular hemoglobin concentration is higher than normal. The red blood cells are darker staining than normal.

hypochromic anemia

Anemia in which hemoglobin is deficient and mean corpuscular hemoglobin concentration is lower than normal.

hypoplastic anemia

A term for aplastic anemia. If anemia caused by failure of formation of red blood cells is meant, pure red blood cell aplasia is the proper term.

inflammatory anemia

Anemia due to chronic disease. Synonym: anemia of chronic inflammation

iron-deficiency anemia

Abbreviation: IDA
Anemia resulting from a greater demand on stored iron supplies than can be provided. The erythrocyte count may sometimes be normal, but there is insufficient hemoglobin. Erythrocytes are hypochromic and show poikilocytosis. IDA is present in about 8% of men and 14% of women ages 3 to 74 years in the U.S.

Etiology

IDA is caused by inadequate iron intake, malabsorption of iron, blood loss, pregnancy and lactation, intravascular hemolysis, or a combination of these factors.

Symptoms

Chronically anemic patients often complain of fatigue and dyspnea on exertion. Iron deficiency resulting from rapid bleeding, may produce palpitations, orthostatic dizziness, or syncope.

Diagnosis

Laboratory studies reveal decreased iron levels in the blood, with elevated iron-binding capacity and a diminished transferrin saturation. Ferritin levels are low. The bone marrow does not show stainable iron.

Additional Diagnostic Studies

Adult nonmenstruating patients with IDA should be evaluated to rule out a source of bleeding in the gastrointestinal tract.

Treatment

Dietary iron intake is supplemented with oral ferrous sulfate or ferrous gluconate (with vitamin C to increase iron absorption). Oral liquid iron supplements should be given through a straw to prevent staining of the teeth. Iron preparations cause constipation; laxatives or stool softeners should be considered as concomitant treatment. When underlying lesions are found in the gastrointestinal tract, e.g., ulcers, esophagitis, cancer of the colon, they are treated with medications, endoscopy, or surgery.

CAUTION!

Parents should be warned to keep iron preparations away from children because three or four tablets may cause serious poisoning.

macrocytic anemia

Anemia marked by abnormally large erythrocytes.

Mediterranean anemia

See: thalassemia

megaloblastic anemia

Anemia in which megaloblasts are found in the blood. Synonym: Zuelzer-Ogden syndrome

microcytic anemia

Anemia marked by abnormally small red blood cells. See: iron-deficiency anemia; thalassemia

milk anemia

In a young child, iron-deficiency anemia caused by consistent consumption of milk in amounts greater than 1 qt daily. This excessive milk intake displaces iron-rich foods in the diet.

anemia of the newborn

Hemoglobin levels less than 14 g/dL in term newborns. Common causes include peripartum bleeding, hemolytic disease of the newborn, twin-to-twin transfusion (15% to 30% of all monochorionic twins with abnormalities of placental blood vessels), and impaired red cell manufacture caused by glucose-6-phosphate dehydrogenase deficiency.

normochromic anemia

Anemia in which the red blood cells contain the normal amount of hemoglobin.

normocytic anemia

Anemia in which the size and hemoglobin content of red blood cells remain normal (the mean corpuscular volume is 80–100 fL).

nutritional anemia

Deficiency anemia.

pernicious anemia

A chronic, macrocytic anemia marked by achlorhydria. It occurs most often in 40- to 80-year-old northern Europeans with fair skin but has been reported in other races and ethnic groups. It is rare in Africans and Asians.

Etiology

Pernicious anemia is an autoimmune disease. The parietal cells of the stomach lining fail to secrete enough intrinsic factor to ensure intestinal absorption of vitamin B12, the extrinsic factor. This is the result of atrophy of the glandular mucosa of the fundus of the stomach and is associated with absence of hydrochloric acid.

Symptoms

Symptoms include weakness, sore tongue, paresthesias (tingling and numbness) of the extremities, and gastrointestinal symptoms such as diarrhea, nausea, vomiting, and pain; in severe anemia, there may be signs of cardiac failure.

Treatment

Vitamin B12 is given parenterally or, in patients who respond, intranasally or orally.

physiological anemia of pregnancy

Pseudoanemia of pregnancy due to an increase of plasma that exceeds the production of red blood cells. See: pseudoanemia of pregnancy

anemia of prematurity

Anemia that gradually develops in the first months of life in an infant born before the 37th week of gestation. It is caused by insufficient production of erythropoietin. Treatment may include red blood cell transfusions to increase iron stores and/or recombinant human erythropoietin.

runner's anemia

Mild hemolysis with hematuria, hemoglobinemia, and hemoglobinuria produced by strenuous exercise, including running. The anemia may be caused by the destruction of red blood cells during repeated striking of the ground by the runner’s feet, by plasma volume expansion, and by intestinal blood loss. Blood may be lost in the feces, presumably due to transient ischemia of the gut during vigorous exercise.

septic anemia

Anemia due to severe infection.

sickle cell anemia

An autosomal recessive disorder that causes an abnormality of the globin genes in hemoglobin. The frequency of the genetic defect responsible for this chronic anemia disorder is highest among African-American, native African, and Mediterranean populations. The disease also affects people from the Caribbean and Central and South America. Approximately 75,000 people in the U.S. have sickle cell anemia. The illness affects one of every 500 African-American babies. Roughly 8% of the African-American population carry the sickle cell trait. Sickle cell anemia during pregnancy increases the risk of crisis, preeclampsia, urinary tract infection, congestive heart failure, and pulmonary infarction. Use of supplemental oxygen during labor is recommended.hemoglobin S disease;

Etiology

When both parental genes carry the same defect, the person is homozygous for hemoglobin S, i.e., HbSS, and manifests the disorder. When exposed to a decrease in oxygen, hemoglobin S becomes viscous. This causes the red cells to become crescent-shaped (sickled), rigid, sticky, and fragile, increasing red-cell destruction (hemolysis). When sickled red blood cells clump together, circulation through the capillaries is impeded, causing obstruction, tissue hypoxia, and further sickling. In infants younger than 5 months old, high levels of fetal hemoglobin inhibit the reaction of the hemoglobin S molecule to decreased oxygen.

Symptoms

The shortened life span of the abnormal red cells (10–20 days) results in a chronic anemia; pallor, weakness, and fatigue are common. Jaundice may result from hemolysis of red cells. Crisis may occur as a result of sickling, thrombi formation, vascular occlusion, tissue hypoxia, and infarction. People with sickle cell anemia are at increased risk of bacterial infections relative to the general population. Specific risks include osteomyelitis, meningitis, pneumonia, and sepsis from agents such as Streptococcus pneumoniae, Mycoplasma, and Chlamydia. Sickle cell patients with fever, cough, and/or regional pain should begin antibiotic therapy immediately after cultures for blood and urine and diagnostic x-rays are obtained. Sickle cell anemia also increases the risk for ischemic organ and tissue damage. Intensely painful episodes (crises) affecting the extremities, back, chest, and abdomen can last from hours to weeks and are the most frequent cause of hospitalization. Crises can be triggered by hypoxemia, infection, dehydration, and worsening anemia. Sickle cell crisis should be suspected in the sickle cell patient with pale lips, tongue, palms, or nail beds; lethargy; listlessness; difficulty awakening; irritability; severe pain; or temperature over 104°F (37.8°C) lasting at least 2 days. Life-threatening complications may arise from damage to specific internal organs, including splenic infarcts, myocardial infarction, acute chest syndrome, liver injury, aplastic anemia, and multiorgan dysfunction syndrome. See: sickle cell crisis

Treatment

Supportive therapy includes supplemental iron and blood transfusion. Administration of hydroxyurea stimulates the production of hemoglobin F and decreases the need for blood transfusions and painful crises. Prophylactic daily doses of penicillin have demonstrated effectiveness in reducing the incidence of acute bacterial infections in children. Life-threatening complications require aggressive transfusion therapy or exchange transfusion, hydration, oxygen therapy, and the administration of high doses of pain relievers. Bone marrow transplantation, when a matched donor is available, can cure sickle cell anemia.

Patient care

During a crisis, patients are often admitted to the hospital to treat pain and stop the sickling process. Adequate pain control is vital. Morphine is the opioid of choice to manage pain because it has flexible dosing forms, proven effectiveness, and predictable side effects. It should be administered using patient-controlled analgesia, continuous low-dose intravenous infusions, or sustained release pain relievers to maintain consistent blood levels. Supplemental short-acting analgesics may be needed for breakthrough pain. Side effects of narcotic pain relievers should be treated with concurrent administration of antihistamines, antiemetics, stool softeners, or laxatives. When administering pain relievers, care providers should assess pain using a visual analog scale to evaluate the effectiveness of the treatment. Other standard pain reduction techniques, such as keeping patients warm, applying warm compresses to painful areas, and keeping patients properly positioned, relaxed, or distracted may be helpful. Patients and families are to be advised never to use cold applications for pain relief because this treatment aggravates sickling. If transfusions are required, packed red blood cells (leukocyte-depleted and matched for minor antigens) are administered, and the patient is monitored for transfusion reactions. Scheduled deep breathing exercises or incentive spirometry helps to prevent atelectasis, pneumonia, and acute chest syndrome. During remission, the patient can prevent some exacerbations with regular medical checkups; the use of medications such as hydroxyurea; consideration of bone marrow transplantation; avoiding hypoxia (as in aircraft or at high altitudes); excessive exercise; dehydration; vasoconstricting drugs; and exposure to severe cold. The child must avoid restrictive clothing, strenuous exercise and body-contact sports but can still enjoy most activities. Additional fluid should be consumed in hot weather to help prevent dehydration. Patients and families should be advised to seek care at the onset of fevers or symptoms suggestive of infectious diseases. Annual influenza vaccination and periodic pneumococcal vaccination may prevent these common infectious diseases. Affected families should be referred for genetic counseling regarding risks to future children and for psychological counseling related to feelings of guilt. Screening of asymptomatic family members may determine whether some are heterozygous carriers of the sickling gene. Families affected by sickle cell anemia may gain considerable support in their communities or from national associations such as the American Sickle Cell Anemia Association, www.ascaa.org.

splenic anemia

Enlargement of the spleen due to portal or splenic hypertension with accompanying anemia, leukopenia, thrombocytopenia, and gastric hemorrhage. See: Banti syndrome; congestive splenomegaly

transfusion-dependent anemia

Anemia for which the only effective therapy is repeated blood transfusions.

CAUTION!

Iron overload may be a complication of therapy, esp. after the transfusion of over 10 units of blood.

Diamond,

Louis Klein, U.S. physician, 1902-1999 Diamond-Blackfan anemia - autosomal recessive normocytic normochromic anemia. Synonym(s): congenital hypoplastic anemia; Diamond-Blackfan syndromeDiamond-Blackfan syndrome - Synonym(s): Diamond-Blackfan anemiaGardner-Diamond syndrome - see under Gardner, Frank HShwachman-Diamond syndrome - Synonym(s): Shwachman syndrome