Learning Objectives
By the end of this section, you will be able to:
- Discuss the pathophysiology, risk factors, and clinical manifestations associated with the common types of anemia
- Describe the diagnostics and laboratory values for anemias
- Apply nursing concepts and plan associated nursing care for the patient with anemia
- Evaluate the efficacy of nursing care for the patient with anemia
- Describe the medical therapies that apply to the care of the patient with anemia
The hematopoietic system consists of the body structures responsible for the formation of blood cells. One of the most common hematopoietic disorders, anemia, is defined as deficient production of red blood cells (RBCs) or of hemoglobin (Hb), a protein in RBCs that is key to the transport of oxygen from the lungs to cells and tissues. Table 16.1 identifies Hb levels in grams per deciliter (g/dL) of blood for different groups of people with and without anemia (WHO, 2024).
| Group | Hb Level (g/dL) | |||
|---|---|---|---|---|
| No Anemia | Mild Anemia | Moderate Anemia | Severe Anemia | |
| Children (>5 years) | ≥11.0 | 10.0–10.9 | 7.0–9.9 | <7.0 |
| Children (5–11 years) | ≥11.5 | 11.0–11.4 | 8.0–10.9 | <8.0 |
| Children (12–14 years) | ≥12.0 | 11.0–11.9 | 8.0–10.9 | <8.0 |
| Nonpregnant females | ≥12.0 | 11.0–11.9 | 8.0–10.9 | <8.0 |
| Pregnancy: First trimester Second trimester Third trimester |
≥11.0 ≥11.0 ≥11.0 |
10.0–10.9 9.5–10.4 10.0–10.9 |
7.0–9.9 7.0 – 9.4 7.0–9.9 |
<7.0 <7.0 <7.0 |
| Males | ≥13.0 | 11.0–12.9 | 8.0–10.9 | <8.0 |
There are several types of anemia, each with distinct causes and clinical presentations, which can make management challenging. Some types, like iron-deficiency anemia, result from insufficient intake of essential nutrients, like iron, in food. In contrast, other anemias, such as sickle cell anemia, are hereditary conditions brought on by genetic mutations. Chronic illnesses, such as chronic kidney disease and inflammatory conditions, often contribute to secondary anemia as a side effect. However, all types of anemia deprive tissues and organs of the oxygen necessary to function optimally. Those affected by the disorder often experience debilitating symptoms including fatigue, weakness, pale skin tone, and shortness of breath. This diversity of causes and effects underscores the importance of being knowledgeable about anemia to ensure accurate diagnosis, appropriate treatments, and successful management for those living with it (Mayo Clinic Staff, 2022).
Life-Stage Context
Anemia in Older People
Older adults are prone to anemia due to declines in their bone marrow production and immunity, as well as increased occurrence of myeloproliferative disorders (Mayo Clinic Staff, 2022). Changes in diet and access to nutrition may also play contributing roles in the prevalence of anemia. Older adults often associate fatigue and cold intolerance as symptoms of aging; however, often it is due to anemia. Nurses must encourage the older patient to get screened for and, if necessary, care for anemia. Supportive interventions centered around the patient’s condition can alleviate symptoms if anemia has been identified as the source (Mayo Clinic Staff, 2022).
Pathophysiology of Anemia
Anemia can have several causes, but its general pathophysiology involves several key mechanisms affecting the production of RBCs. RBCs are produced within bone marrow. If bone marrow is damaged, such as from osteoporosis or bone cancer, it may no longer produce enough RBCs to meet the body’s needs (WHO, 2024). Kidney damage can also hinder RBC production. In a healthy system, hypoxemia triggers the kidneys to release the hormone erythropoietin (EPO), which, in turn, stimulates the bone marrow to produce RBCs. If the kidneys are damaged, such as in acute or chronic renal failure, the secretion of EPO may decrease or fully stop (WHO, 2024).
Another cause of anemia is blood loss or hemorrhage that exceeds normal RBC production, creating a net negative volume. Anemia can result from acute bleeding, as in trauma or surgery, or from chronic, low-level bleeding, as in gastrointestinal bleeding or heavy menstrual periods. When RBC loss exceeds RBC replacement, the blood loses oxygen-carrying capacity, threatening the ability of cells and tissues to function.
Nutritional deficiencies can also contribute to chronic anemia. Vitamins such as B12 and folate, and minerals such as iron, are essential in RBC production. When they are deficient, the resulting RBCs may be ineffective in volume, color, quality, or quantity.
Another route leading to anemia is the rapid destruction of RBCs, or hemolysis. In hemolytic anemia, RBCs are destroyed faster than they can be produced. This disorder may result from genetic or extrinsic causes, including autoimmune reactions, infections, and side effects of certain medications.
Pernicious Anemia
Vitamin B12 malabsorption anemia, known as pernicious anemia, occurs due to inadequate amounts of vitamin B12, a nutrient that plays a key role in producing healthy RBCs. Vitamin B12 deficiency often results from either an autoimmune attack against parietal cells in the stomach lining or impairment of the chief cells in the gastric lining of the stomach. Both types of cells are necessary to produce and secrete intrinsic factor, an essential protein needed for the absorption of vitamin B12 by the small intestine. Patients who undergo weight loss surgery in which parts of the stomach are excised, altering production of intrinsic factor and absorption of vitamin B12, are also at risk of pernicious anemia. Symptoms of pernicious anemia include fatigue, weakness, pale skin, and neurological symptoms such as tingling and numbness in extremities.
Link to Learning
To prevent pernicious anemia, it is important to eat foods that are high in vitamin B12. This fact sheet about vitamin B12 by the National Institutes of Health includes information about this important nutrient, including daily recommended amounts and foods that are rich in the vitamin.
Folate-Deficiency Anemia
Folate, also called folic acid or vitamin B9, is essential to the production of DNA, but it also helps RBCs form and develop. Megaloblastic anemia, or folate-deficiency anemia, results from inadequate levels of folate, resulting in diminished production of healthy RBCs and Hb. A common cause of this disorder is impaired DNA synthesis within bone marrow, leading to the production of abnormally large and immature RBCs (WHO, 2024). These abnormal cells cannot transport oxygen effectively, leading to symptoms associated with anemia, including fatigue, weakness, pale skin, and tingling or numbness in the extremities. Treatment options may include changes to diet, though it may be necessary to take lifelong folate supplements.
Link to Learning
To prevent folate-deficiency anemia, it is important to eat foods that are high in vitamin B9. This fact sheet about vitamin B9 by the Harvard School of Public Health includes information about folate, including daily recommended amounts and foods that are rich in the vitamin.
Iron-Deficiency Anemia
The mineral iron is necessary to form Hb. An iron-deficiency anemia arises from insufficient levels of iron in the body leading to inadequate Hb formation. This disorder may develop from inadequate iron intake, impaired iron absorption (e.g., from celiac disease or weight-loss surgery), or increased iron loss (e.g., from menstruation or gastrointestinal bleeding) (Camaschella, 2019). An iron-rich diet is key for supporting Hb production and avoiding iron-deficiency anemia. Furthermore, certain foods, such as those high in vitamin C, can facilitate iron absorption, whereas other foods, particularly those high in calcium, can inhibit it. Thus, when consuming foods with iron, it may be wise to avoid also consuming calcium-rich dairy products. Furthermore, animal sources of iron may provide more efficient absorption compared with vegetable sources.
Link to Learning
To prevent iron-deficiency anemia, it is important to eat foods that are high in iron. This iron fact sheet by the National Institutes of Health includes information about iron, including daily recommended amounts and foods that are rich in the mineral.
Other Causes of Anemia
Anemia can also be caused by various autoimmune conditions and chronic diseases that affect RBC production. Cancers and cancer treatments can also lead to anemia. For example, the cytotoxic effects (i.e., harmful impacts) of chemotherapy may inhibit hematopoiesis (the process by which the body manufactures RBCs), and cancer cells often invade bone marrow or alter production of EPO in the kidneys (NHLBI, 2021). Other anemias occur as secondary effects from chronic or autoimmune diseases, such as rheumatoid arthritis, as well as those due to advanced age, chronic infection, or kidney disease can create inflammation and disrupt iron metabolism (Weiss et al., 2019).
Clinical Manifestations
Anemia’s exact pathophysiology depends on its cause; however, all forms share one characteristic: an inability to provide enough oxygen to meet bodily needs, which has serious ramifications for health and well-being. Regardless of the etiology or cause, symptoms of anemia include fatigue, weakness, pallor, and shortness of breath. In more serious cases, the disorder can cause complications affecting the heart, brain, and other vital organs. People with anemia may also feel lightheaded, which can be exacerbated by position changes, and they may experience impairment of their memory or other cognitive processes.
Diagnostics and Laboratory Values
Blood tests are a foundational method of diagnosing and classifying anemia as well as other hematological conditions. They offer key insight into the RBCs and other components of a blood sample. A hemogram is a detailed analysis of a blood sample that examines not only the quantity of RBCs, WBCs, and platelets but also their size, color, and the percentage of iron in them. The following terms are important for understanding and interpreting a hemogram:
- The root chromic refers to the color of a cell.
- The root cytic refers to a cell.
- The prefix micro- signifies a size measurement that is below the normal parameter.
- The prefix macro- signifies a size measurement that is above the normal parameter.
- The mean corpuscular volume (MCV) describes the average size of an RBC.
- The mean corpuscular hemoglobin concentration (MCHC) describes the concentration of Hb in a single RBC.
Table 16.2 connects different types of anemia with results from a hemogram. Remember that regardless of the color and size of the RBCs, anemia is characterized by a lower-than-normal quantity of RBCs resulting in hypoxemia.
| Type of Anemia | Reference Range | Laboratory Description |
|---|---|---|
| Microcytic anemia |
|
|
| Microchromic anemia |
|
|
| Macrocytic anemia |
|
|
| Macrochromic anemia |
|
|
| Normochromic anemia |
|
|
Nursing Care of the Patient with Anemia
Nursing care for individuals with anemia must be tailored according to the type and severity of the disorder, as well as the patient’s specific symptoms, needs, and circumstances. Collaboration among health-care team members and patient education are both integral in providing comprehensive care for those affected by anemia (Weiss et al., 2019).
Recognizing and Analyzing Cues
Nurses must recognize and analyze signs of anemia through a holistic assessment that encompasses both subjective and objective information. Subjective symptoms that might signal anemia include fatigue, weakness, dizziness, and shortness of breath. Nurses should actively listen to patient complaints, ask about the onset and progression of symptoms, and consider medical histories and risk factors.
Objective signs may include physical findings such as pale skin and mucus membranes and delayed capillary refill time. Nurses should look for signs of decreased perfusion in vital sign deviations, including hypotension, tachycardia, and a low pulse oximetry. A review of laboratory blood test results, such as a complete blood cell (CBC) count, will show a low Hb level. Nurses should assess for any signs and symptoms of bleeding, which include reports of increased bruising, bloody stools, bloody urine, frequent heavy menstrual cycle patterns, and problems with bloody noses or bleeding guns. A nutritional assessment can identify any dietary deficiencies.
Link to Learning
To identify anemia quickly, it is important to understand which vital signs might change and why. Recognizing changes in your patients’ vital signs is the first step in critical thinking.
Prioritizing Hypotheses, Generating Solutions, and Taking Action
Once anemia has been diagnosed, stabilization of the disorder and treatment of the underlying cause are the priorities. Nursing interventions for patients with anemia depend on the underlying cause, and can include:
- administering medications to reverse interventions that caused excess bleeding, such as vitamin K to induce blood clotting and reverse an elevated international normalized ratio (discussed later in this chapter) due to high warfarin levels
- frequently assessing vital signs to monitor hemodynamic trends and symptoms due to anemia
- instituting fall precautions to reduce patient harm
- monitoring for bleeding by collecting occult stool samples, drawing blood samples for measurement of serial Hb and hematocrit (Hct) levels to monitor trends, and documenting output from any drains
- providing supplemental oxygen, as prescribed, to patients with transient hypoxia
- transfusing prescribed blood products
Patients with stable anemia are often cared for on medical-surgical floors, though they may require surgical consultations or, in worse cases, surgery to identify any bleeding. Patients with severe, symptomatic cases may require close monitoring in the intensive care unit. Once the anemia has been stabilized, the patient is likely to experience weakness. To avoid fatigue, activities of daily living should be performed in clusters, or planned rest periods should be provided between activities.
Patient education should focus on the type of anemia, its causes and effects, and the importance of following prescribed treatments. Instruct the patient on how to prevent complications and manage anemia-related symptoms. Provide education about prescribed therapies, including dietary recommendations, purposes, and medications. Include nutritional recommendations to increase oral iron intake, if necessary.
Finally, schedule follow-up appointments and laboratory tests, as necessary, to assess the patient’s response to therapy, adjust interventions, and quickly report any side effects or concerns to the health-care team.
Evaluation of Nursing Care for the Patient with Anemia
Evaluation is a crucial element of nursing practice that enables nurses to assess the efficacy of nursing interventions provided to patients with anemia.
Evaluating Outcomes
To evaluate the effectiveness of nursing interventions, the desired goal must first be identified and then compared with the outcomes. The following are examples of outcomes the nurse would evaluate for a patient with anemia:
- Blood pressure, respiratory rate, and oxygenation saturation levels have returned to target ranges.
- Neurological findings of syncope and altered consciousness are resolved and improved.
- Nutritional improvements include increasing dietary intake of vitamin B12, iron, and folate.
- The patient reports improvement of symptoms, such as less fatigue and shortness of breath; the patient is able to complete activities of daily living.
- The patient reports reduced levels of pain secondary to alteration in perfusion.
Medical Therapies and Related Care
Treatment of anemia depends upon accurately diagnosing the cause, including any nutritional deficiencies involved (Mayo Clinic Staff, 2022). Appropriate therapies may include nutritional support; pharmacological support, such as RBC-stimulating agents; and, in acute or severe symptomatic presentations, blood transfusion. If anemia is a secondary effect of another health condition, like gastrointestinal bleeding or chronic inflammation disease, it will be necessary to treat that condition.
Iron supplementation is a needed treatment when iron is low, because RBCs require iron for full functioning. Oral iron supplements may be taken up to three times a day with food to boost body stores of iron and promote appropriate production of RBCs. These supplements may come in the form of ferrous sulfate, ferrous gluconate, or other iron preparations. Consuming iron with vitamin C potentiates its effectiveness, whereas taking it with calcium can delay the absorption. Caution patients that iron supplements may cause a darkened stool and some constipation. Adequate water intake is essential. Proper supplementation is also essential for pernicious anemia and folate-deficiency anemia. Folate is dosed with daily supplements or can be administered as a subcutaneous injection.
When severe symptoms or complications develop due to anemia, blood transfusion may become necessary. Donated blood can quickly replace depleted RBC counts. EPO therapy stimulates RBC production from bone marrow. Recombinant human EPO may be prescribed to those experiencing anemia caused by chronic kidney disease or cancer treatments like chemotherapy. Medications, such as darbepoetin alfa and epoetin alfa, may help stimulate bone marrow to produce more RBCs by acting on the bone marrow. Bone marrow stimulants are commonly administered subcutaneously to patients who are dialysis dependent.