Flashcards in Chapter 30 Hematologic Problems Deck (34)
Definition and Classification
1) A deficiency in number of erythrocytes (red blood cells [RBCs])
2) the quantity or quality of hemoglobin
3) and/or volume of packed RBCs (hematocrit).
- prevalent condition with many diverse causes, such as blood loss, impaired production of erythrocytes, or increased destruction of erythrocytes
- Because RBCs transport O2, erythrocyte disorders can lead to tissue hypoxia. This hypoxia accounts for many of the signs and symptoms of anemia.
- Anemia is not a specific disease. It is a manifestation of a pathologic process.
What are the causes of decrease RBC production?
1) Deficient nutrients
2) Decreased erythropoietin
3) Decreased iron availability
What are the causes of blood loss?
-Bleeding duodenal ulcer
-Ruptured aortic aneurysm
What are the causes of increased RBC destruction?
*Sickle cell diseae
*Medication (e.g Methyldopa [Aldomet])
*Trauma (Cardiopulmonary bypass)
Anemia is diagnosed based on?
1) A complete blood count (CBC)
2) reticulocyte count
3) peripheral blood smear.
- Once anemia is identified, further investigation is done to determine its specific cause
Anemia can result from?
1) primary hematologic problems
2) develop as a secondary consequence of diseases or disorders of other body systems.
The various types of anemia can be classified according to either?
1) morphology (cellular characteristic)
2) etiology (cause)
- Morphologic classification is based on RBC size and color.
- Etiologic classification is related to the clinical conditions causing the anemia
- Although the morphologic system is the most accurate means of classifying anemias, it is easier to discuss patient care by focusing on the etiology of the anemia.
• Sickle cell disease has a high incidence among?
• Thalassemia has a high incidence among?
• Tay-Sachs disease has the highest incidence in?
• Pernicious anemia has a high incidence among?
• Sickle cell disease has a high incidence among African Americans.
• Thalassemia has a high incidence among African Americans and people of Mediterranean origin.
• Tay-Sachs disease has the highest incidence in families of Eastern European Jewish origin, especially the Ashkenazi Jews.
• Pernicious anemia has a high incidence among Scandinavians and African Americans.
The clinical manifestations of anemia are caused by the body's response to tissue hypoxia. Specific manifestations vary depending on the?
rate at which the anemia has evolved, its severity, and any coexisting disease. Hemoglobin (Hgb) levels are often used to determine the severity of anemia
Mild states of anemia may exist without causing symptoms. If symptoms develop, it is because the patient has an?
(Hgb 10 to 12 g/dL [100 to 120 g/L])
- underlying disease or is experiencing a compensatory response to heavy exercise.
- Symptoms include palpitations, dyspnea, and mild fatigue.
(Hgb 6 to 10 g/dL [60 to 100 g/L])
- cardiopulmonary symptoms are increased (Increased HR, etc.). The patient may experience them while resting, as well as with activity.
Used to determine the severity of anemia
Hemoglobin (Hgb) levels
In severe anemia the patient has?
(Hgb less than 6 g/dL [60 g/L])
- many clinical manifestations involving multiple body systems
Body System: Cardiovascular
Mild (Hgb 10-12 g/dL [100-120 g/L])
Moderate (Hgb 6-10 g/dL [60-100 g/L])
Severe (Hgb <6 g/dL [<60 g/L])
1) Mild: Palpitations
2) Moderate: Increased palpitations, “bounding pulse”
3) Severe: Tachycardia, increased pulse pressure, systolic murmurs, intermittent claudication, angina, heart failure, myocardial infarction
Morphologic Classification of Anemia
Morphology: Normocytic, normochromic
- Morphology: (normal size and color) MCV 80-100 fL, MCH 27-34 pg
- Etiology: Acute blood loss, hemolysis, chronic kidney disease, chronic disease, cancers, sideroblastic anemia, endocrine disorders, starvation, aplastic anemia, sickle cell anemia, pregnancy
Morphologic Classification of Anemia
Morphology: Microcytic, hypochromic
-Morphology: (small size, pale color) MCV <80 fL, MCH <27 pg
-Etiology: Iron-deficiency anemia, vitamin B6 deficiency, copper deficiency, thalassemia, lead poisoning
Morphologic Classification of Anemia
Morphology: Macrocytic (megaloblastic)
- Morphology: (large size, normal color) MCV >100 fL, MCH >34 pg
- Etiology: Cobalamin (vitamin B12) deficiency, folic acid deficiency, liver disease (including effects of alcohol abuse)
Iron-deficiency anemia is the most common nutritional disorder in the world. Those most susceptible to iron-deficiency anemia are the?
very young, those on poor diets, and women in their reproductive years.
- Normally 1 mg of iron is lost daily in urine, bile, sweat, sloughing of epithelial cells from the skin and intestinal mucosa, and minor bleeding
1) Iron-deficiency anemia may develop as a result of?
2) Normal dietary iron intake is usually sufficient to meet the needs of men and older women, but it may be inadequate for?
1) inadequate dietary intake, malabsorption, blood loss, or hemolysis.
2) individuals with higher iron needs (e.g., menstruating or pregnant women). Table 30-5 lists nutrients needed for erythropoiesis
Malabsorption of iron
- May occur after certain types of gastrointestinal (GI) surgery and in malabsorption syndromes
- Surgical procedures may involve removal or bypass of the duodenum
- As iron absorption occurs in the duodenum, malabsorption syndromes may involve disease of the duodenum in which the absorption surface is altered or destroyed.
Blood loss is a major cause of iron deficiency in adults. Two milliliters of whole blood contain 1 mg of iron. The major sources of chronic blood loss are from the?
GI and genitourinary (GU) systems.
- GI bleeding is often not apparent and therefore may exist for a considerable time before the problem is identified.
- Loss of 50 to 75 mL of blood from the upper GI tract is required for stools to appear black (melena). The black color results from the iron in the RBCs.
Iron deficiency anemia
1) Common causes of GI blood loss are peptic ulcer, gastritis, esophagitis, diverticula, hemorrhoids, and neoplasia.
2) GU blood loss occurs primarily from?
3) The average monthly menstrual blood loss is about?
4) Postmenopausal bleeding can contribute to?
5) In addition to anemia of chronic kidney disease, dialysis treatment may cause iron-deficiency anemia because of the?
1) peptic ulcer, gastritis, esophagitis, diverticula, hemorrhoids, and neoplasia.
2) menstrual bleeding.
3) 45 mL and causes the loss of about 22 mg of iron.
4) anemia in a susceptible older woman.
5) blood lost in the dialysis equipment and frequent blood sampling.
In the early course of iron-deficiency anemia, the patient may not have any symptoms. As the disease becomes chronic, any of the general manifestations of anemia may develop. In addition, specific clinical manifestations may occur related to iron-deficiency anemia.
- Pallor most common finding
- glossitis (inflammation of the tongue) second most common
- cheilitis (inflammation of the lips)
- patient may report headache, paresthesias, and burning sensation of tongue, all caused by lack of iron in the tissues.
Iron deficiency anemia
Laboratory abnormalities characteristic of iron-deficiency anemia are presented in Table 30-6. Other diagnostic studies (e.g., stool occult blood test) are done to determine the?
cause of the iron deficiency. Endoscopy and colonoscopy may be used to detect GI bleeding. A bone marrow biopsy may be done if other tests are inconclusive.
Teach the patient which foods are good sources of iron
- Liver and muscle meats
- dried fruits
- dark green leafy vegetables
- whole-grain and enriched bread and cereals
• History and physical examination
• Hct and Hgb levels
• RBC count, including morphology
• Reticulocyte count
• Serum iron
• Serum ferritin
• Serum transferrin
• Total iron-binding capacity (TIBC)
• Stool examination for occult blood
Iron deficiency anemia management
• Identification and treatment of underlying cause
• Drug therapy
• Oral: Ferrous sulfate or ferrous gluconate
• IM or IV: Iron dextran, sodium ferrous gluconate, iron sucrose
• Nutritional therapy
• Transfusion of packed RBCs
Oral iron should be used whenever possible because it is inexpensive and convenient. Many iron preparations are available. When administering iron, consider the following five factors:
1. absorbed best from duodenum and proximal jejunum. Therefore enteric-coated or sustained-release capsules, which release iron farther down in the GI tract, are counterproductive and expensive.
2. daily dose provides 150 to 200 mg of elemental iron. can be ingested in three or four daily doses, with each tablet or capsule of iron preparation containing between 50 and 100 mg of iron (e.g., a 300-mg tablet of ferrous sulfate contains 60 mg of elemental iron).
3. best absorbed as ferrous sulfate (Fe2+) in acidic environment. For this reason and to avoid binding the iron with food, iron should be taken about an hour before meals, when the duodenal mucosa is most acidic. Taking iron with vitamin C (ascorbic acid) or orange juice, which contains ascorbic acid, enhances iron absorption. Gastric side effects, however, may necessitate ingesting iron with meals.
4. Undiluted liquid iron may stain teeth. Therefore it should be diluted and ingested through a straw.
5. GI side effects of iron administration may occur, including heartburn, constipation, and diarrhea. If side effects develop, the dose and type of iron supplement may be adjusted. For example, many individuals who need supplemental iron cannot tolerate ferrous sulfate because of the effects of the sulfate base. However, ferrous gluconate may be an acceptable substitute. Tell patients that the use of iron preparations will cause their STOOLS to become BLACK because the GI tract excretes excess iron. Constipation is common, and patient should be started on stool softeners and laxatives, if needed, when started on iron.
• Some preparations of IV iron have a risk of?
• Oral iron should be taken?
• Vitamin C (ascorbic acid) does what to iron?
• an allergic reaction, and the patient should be monitored accordingly.
• about 1 hr before meals.
• enhances iron absorption.