Chronic Anemia and the Role of the Infusion Therapy Nurse
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VOLUME 38 | NUMBER 5 | SEPTEMBER/OCTOBER 2015 The Art and Science of Infusion Nursing Jeffrey Betcher, RPh, BCOP Velvet Van Ryan, BSN, RN, OCN® Joseph Mikhael, MD Chronic Anemia and the Role of the Infusion Therapy Nurse destruction of erythrocytes. They encompass a broad ABSTRACT range of anemias that develop acutely or chronically Chronic anemia develops over a course of weeks and may persist for several months if left untreated. to months and is usually mild to moderate in Formally, anemia of chronic disease is a specific catego- nature. It is important to understand the etiology ry of anemia associated with underlying infection, of the reduced number of circulating red blood inflammation, or malignancy. For the purpose of this cells to treat the anemia appropriately. Diagnosis publication, the term chronic anemia will be used to is dependent on patient history and laboratory encompass anemia of chronic disease; anemia of chron- findings, such as complete blood counts, iron ic kidney disease (CKD); anemia of cancer; and vitamin studies, a peripheral smear, and occasionally, a B12, folate, and iron deficiency anemias. On diagnosis, the infusion therapy nurse may be involved with treat- bone marrow biopsy. Treatment modalities fre- ment strategies ranging from treatment of an underlying quently administered by infusion therapy nurses chronic disease, replacement of deficiencies (iron, vita- include treatment of the underlying chronic dis- min B12, folate, or erythropoietin), or transfusion of ease, replacement of deficiencies (iron, vitamin red blood cells (RBCs) in symptomatic patients or those B12, folate, or erythropoietin), or transfusion of with cardiovascular instability. Normal erythropoiesis, red blood cells. Infusion therapy nurses play a clinical and laboratory findings, etiology, medications vital role in the assessment and delivery of medi- used for treatment of chronic anemia, and the role of cation therapy to patients with chronic anemia. the infusion therapy nurse in the delivery of care to Key words: anemia, chronic, ESA, iron, infusion patients will be reviewed. nemia is defined as a reduction below nor- ERYTHROPOIESIS mal of the number of erythrocytes, quan- tity of hemoglobin (Hgb), or volume of RBCs are unable to divide into new cells and live on red cells in the blood. Anemia occurs by 1 average about 120 days. To replenish themselves, aged or more of 3 mechanisms: blood loss, and ruptured cells must be replaced by new cells. The Adecreased production of erythrocytes, and increased body replaces approximately 1% of its total RBCs on a 1 destruction of erythrocytes. Chronic anemias result daily basis. This process is called erythropoiesis. When primarily from a decreased production of erythrocytes, the body has an increased need for RBC production with or without accompanying blood loss or increased secondary to anemia, the kidneys sense tissue hypoxia and increase secretion of the hormone erythropoietin. Author Affiliation: Mayo Clinic, Phoenix, Arizona. Jeffrey Betcher, RPh, BCOP, is a clinical pharmacy specialist at the Erythropoietin travels to the bone marrow by means of Mayo Clinic in Phoenix. the circulatory system and stimulates differentiation of Velvet Van Ryan, BSN, RN, OCN®, is a unit-based educator at hematopoietic stem cells. As the differentiated cells, the Mayo Clinic in Phoenix. known as erythroblasts, mature, they fill with Hgb and Joseph Mikhael, MD, is an associate professor of medicine at the release their nucleus. Vitamin B12 and folate are critical Mayo Clinic College of Medicine and a consultant at the Mayo to DNA synthesis within the nucleus.2 The release of the Clinic in Phoenix. The authors have no conflicts of interest to disclose. nucleus causes the cell to collapse on itself, creating a Corresponding Author: Joseph Mikhael, MD, 13400 East Shea disk-like formation. This formation allows for increased Boulevard, Scottsdale, AZ 85259 ([email protected]). cell surface so Hgb can attract more oxygen molecules. DOI: 10.1097/NAN.0000000000000122 Hgb is responsible for the red color of the RBC. The VOLUME 38 | NUMBER 5 | SEPTEMBER/OCTOBER 2015 Copyright © 2015 Infusion Nurses Society 341 Copyright © 2015 Infusion Nurses Society. Unauthorized reproduction of this article is prohibited. JIN-D-14-00056.indd 341 28/08/15 9:22 PM mature RBC is then released into the bloodstream. Near This is important in early diagnoses of iron deficiency the end of RBC life, macrophages engulf the RBC, and anemia. Tsat measures the absorption and transporta- iron is recycled for a new generation of RBCs. Large tion of dietary iron. Transferrin is a protein that binds amounts of iron, which is stored in ferritin, are required iron. TIBC measures the blood’s capacity to bind iron for Hgb production. and transferrin. Ferritin and transferrin levels are used to calculate the TIBC. Figure 1 illustrates a classifica- tion algorithm for the chronic anemias. CLINICAL AND LABORATORY FINDINGS ETIOLOGY A thorough patient history is critical to the evaluation The 3 major mechanisms of anemia are: and management of patients with anemia. Classic pres- 1. Blood loss (acute or chronic) entation may include pale appearance, fatigue, weak- 2. Decreased RBC production ness, anorexia, insomnia, shortness of breath, dizziness, a. Defect in stem cells (aplastic anemia, pure red headache, decreased mental and physical performance, cell aplasia) pica, and palpitations. However, it is important to rec- b. Defect in heme production (iron deficiency, ognize that not all patients with anemia present with thalassemias) these classic symptoms; an underlying chronic illness c. Defective DNA production (vitamin B12 and may frequently mask the symptoms of anemia. folic acid deficiencies) The provider’s physical examination of the patient d. Destruction of bone marrow (solid tumor with suspected anemia should include inspection of gen- metastasis, inherent marrow malignancy, or eral appearance, vital signs, assessment for skin pallor, a other marrow invasion) cardiac exam, and evaluation for splenomegaly. 3. Increased red cell destruction Laboratory studies remain the mainstay of diagnosis a. Caused by external factors and determining etiology of the anemia. This includes a b. Caused by hereditary internal factors complete blood count (CBC), iron studies, and a periph- c. Caused by an acquired defect1 eral smear. Important components of the CBC are Hgb, hematocrit (Hct), reticulocytes, mean corpuscular vol- The chronic anemias generally develop as a result of ume (MCV), and RBC distribution. Leukocytes and an underlying cause that decreases RBC production and platelets are also a part of the CBC and are less relevant may or may not have an associated blood loss or to the diagnosis of anemia but may have utility in ruling increase in red cell destruction. out other hematological causes such as leukemia. Suspicion of iron deficiency anemia warrants iron stud- Anemia of Chronic Disease ies (ie, serum iron, ferritin, total iron binding capacity [TIBC], and transferrin saturation [Tsat]). Vitamin B12 The pale appearance of patients with chronic infections and folate levels are important for diagnosis and differ- such as tuberculosis was recognized hundreds of years entiation of megaloblastic anemias. Erythropoietin lev- ago. The pallor was eventually attributed to an anemia els should be considered with a diagnosis of anemia of of chronic disease, which occurs when an inflammatory chronic disease, anemia of CKD, and anemia of cancer. process causes erythrocytes to have a decreased life Initial suspicion of anemia is based on a low Hgb or span, as well as a poor bone marrow erythropoiesis Hct. Anemia is generally classified by cell size. RBC response. More recently, the designation anemia of indices will give the MCV, which is the size, thickness, inflammation has been recommended because it is and volume of the RBC. Microcytic anemias are those thought to be more reflective of the pathophysiology of with low MCV. These cells are also hypochromic, indi- this anemia, which also includes anemia of critical ill- cating that they have a low Hgb concentration. These ness, a condition that presents similarly to anemia of anemias are generally associated with iron deficiency chronic disease but develops acutely within days of the and chronic inflammation.3 Macrocytic anemias are onset of illness.5 those with elevated MCV and are generally associated For the purpose of this article, anemia of chronic with vitamin B12 and folic acid deficiency. Last is nor- disease will be used. This anemia is thought to be mocytic anemia, which presents with normal-sized caused by inhibitory effects of inflammatory cytokines RBCs. This anemia can be found in renal insufficiency released in response to the effects of an underlying and bone marrow infiltration.3 chronic disease on erythropoiesis.6 Erythropoietin pro- Serum ferritin, Tsat, and TIBC can be used individu- duction is less than expected, and the inflammatory ally or in conjunction to aid in diagnosing anemia. process also induces a relative resistance to the effects of Serum ferritin measures iron provisions in the body. erythropoietin. Iron availability is also compromised 342 Copyright © 2015 Infusion Nurses Society Journal of Infusion Nursing Copyright © 2015 Infusion Nurses Society. Unauthorized reproduction of this article is prohibited. JIN-D-14-00056.indd 342 28/08/15 9:22 PM Figure 1 Classification of anemia by laboratory findings. Data from Young and Koda-Kimble (1995).4 Abbreviations: