Chapter 30 Hematologic Problems Flashcards
Anemia
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
- iron
- cobalamin
- folic acid
2) Decreased erythropoietin
3) Decreased iron availability
What are the causes of blood loss?
1) Chronic
- Bleeding duodenal ulcer
- Colorectal cancer
- Liver disease
2) Acute
- Acute trauma
- Ruptured aortic aneurysm
- GI bleeding
What are the causes of increased RBC destruction?
- Hemolysis
- Sickle cell diseae
- Medication (e.g Methyldopa [Aldomet])
- Incompatible blood
- 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
or
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)
or
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.
Hematologic Problems
• 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.
Moderate anemia
(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
Etiology:
- 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
Etiology:
- 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)
Etiology:
- 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
Etiology
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.
Clinical Manifestations
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
Diagnostic Studies
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.
