Anemia, Iron Deficiency (Microcytic, Hyprochromic)
Julie Adkins, Jill C. Cash, Beverly R. Byram, Cheryl A. Glass, Kristin Ownby, and Pat Obulaney
Definition
A.Microcytic anemia is characterized by small, pale red blood cells (RBCs) and depletion of iron (Fe) stores. The hematocrit (Hct) is less than 41% in males, with a hemoglobin (Hgb) less than 13.5 g/dL. In females, the Hct is less than 37% with a Hgb less than 12 g/dL. Usually mild, it can become moderate or severe.
Incidence
A.Iron deficiency is the most common cause of anemia worldwide; it is particularly prevalent in women of child-bearing age. It is estimated to occur in 20% of adult women, 19% of patients 80 years of age and older, 50% of pregnant women, and 3% of adult males in the United States. Prevalence rates are highest among African American and Hispanic populations.
Pathogenesis
A.Anemia is acquired; it develops slowly and in stages. Iron loss exceeds intake so that stored iron is progressively depleted. As stored iron is depleted, a compensatory increase in absorption of dietary iron and in the concentration of transferrin occurs. Iron stores can no longer meet the needs of the erythroid marrow; the plasma transferrin level increases and the serum iron concentration declines, resulting in a decrease in iron available for RBC formation.
Predisposing Factors
A.Female with history of heavy menses.
B.Chronic blood loss, gastrointestinal (GI) blood loss.
C.Family history or personal history of anemia.
D.Poor diet, including strict vegetarian diets.
E.Closely spaced pregnancies.
F.Pica.
G.Chronic hemoglobinuria due to an abnormally functioning cardiac valve.
H.Chronic aspirin use, anticoagulant, or nonsteroidal anti-inflammatory drug (NSAID) use.
I.Repeated blood donation.
J.Decreased iron absorption due to gastric surgery.
K.Taking too many antacids that contain calcium.
L.Surgeries including gastric bypass surgery, orthopedic surgeries, abdominal surgeries, and cardiac surgeries.
M.GI problems including Helicobacter pylori, autoimmune gastritis, and celiac disease.
N.Chronic kidney disease.
O.Hookworms, whipworms.
P.Chronic use of proton pump inhibitors (PPIs) or histamine 2 antagonist.
Common Complaints
A.Fatigued all of the time.
B.Heart feels like it is racing, beating hard.
C.Out of breath on exertion.
D.Loss of appetite, nausea, and vomiting.
E.Headaches throughout day.
F.Weak and dizzy.
Other Signs and Symptoms
Clinical presentation depends on severity, patient’s age, and the ability of the cardiovascular and pulmonary systems to compensate for the decreasing oxygen-carrying capacity of the blood.
A.Initial: Exercise-induced dyspnea and mild fatigue symptoms may be minimal until the patient has significant anemia.
B.As Hct falls, dyspnea and fatigue increase:
1.Malaise.
2.Drowsiness.
3.Sore tongue and mouth.
4.Skin pallor.
5.Pale mucous membranes and conjunctiva.
6.Pale fingernail beds.
7.Tachycardia.
8.Palpitations.
9.Tinnitus.
C.Severe anemia:
1.Atrophic glossitis, cheilitis (lesions at the corner of the mouth).
2.Koilonychia (thin concave fingernails with raised edges).
Subjective Data
A.Inquire about onset, course, and duration of symptoms.
B.Ask the patient about past history of GI bleeding.
C.Take careful history of GI complaints that might suggest gastritis, peptic ulcer disease, or other conditions that might produce GI bleeding.
D.Ask if there has been a change in stool color or bleeding from hemorrhoids.
E.In menstruating women, ask about blood loss during menses.
F.Ask about dietary intake of iron-rich foods and pica.
G.Obtain medication history, especially use of aspirin, anti-coagulants, and other NSAIDs.
H.Rule out history of anemia, blood-clotting problems, sickle cell disease, glucose-6-phosphate dehydrogenase (G6PD) deficiency, or other hereditary hemolytic diseases.
I.Review occupation and activities with exposure to lead or lead paint.
J.Has the patient experienced palpitations, chest pain, dizziness, or shortness of breath, especially on exertion or activity?
K.Ask about symptoms of severe anemia including chest pain, dyspnea at rest, and palpitations.
Physical Examination
A.Check temperature, pulse, respirations, blood pressure, and weight. Check for postural hypotension.
B.Inspect:
1.Inspect general appearance; the patient may be pale, lethargic, or without overt signs if anemia is mild.
2.Conduct eye exam; check conjunctivae for paleness.
3.Examine oral mucosa, corners of the mouth (for cheilitis); note appearance of the tongue (atrophy of the papillae; smooth, shiny, beefy red appearance), angular stomatitis, or pale gums.
4.Examine the skin for dryness and perfusion.
5.Examine nails for brittleness, flattening, ridges, and concave or spoon shape.
C.Palpate: Palpate the abdomen for tenderness and enlargement of the liver and spleen.
D.Percuss: Percuss the abdomen.
E.Auscultate: Auscultate the heart for systolic flow murmurs, tachycardia.
F.Rectal exam: Assess for masses and obtain stool for occult blood.
Diagnostic Tests
A.Initial screening:
1.Complete blood count (CBC) with differential and peripheral smear.
2.Serum ferritin level, serum iron, total iron-binding capacity (TIBC), retic count, RBC indices.
3.Serum iron concentration: Absent iron stores equal ferritin value less than 30 ng/mL.
4.Urinalysis.
5.Stool for occult blood.
B.Follow-up testing:
1.TIBC: Serum ferritin, TIBC rises.
2.Hct 3 to 4 weeks after treatment. Treatment should continue for at least 4 to 6 months after the Hct returns to normal.
3.GI series, if indicated.
4.Upper and lower endoscope, if indicated.
5.Ultrasonography or CT scan, if indicated.
Differential Diagnoses
A.Iron deficiency anemia.
B.Inadequate intake of iron.
C.Any condition that causes acute or chronic blood loss.
D.Hemolytic diseases such as sickle cell and G6PD deficiency.
E.Anemia of chronic disease, thalassemia, and sideroblastic anemias.
F.Lead poisoning.
G.Neoplasm.
Plan
A.General interventions: Identify source of anemia. Discuss dietary sources of iron-rich foods. Discuss foods to avoid because they impair absorption.
B.
See Section III: Patient Teaching Guide Iron-Deficiency Anemia
:
1.Stress the importance of dietary intake of foods high in iron, which is absorbed better than most vitamins. Foods rich in Vitamin C or ascorbic acid 500 mg daily increases absorption of iron. Tea and milk reduce iron absorption.
2.Provide iron supplements. Dose according to iron lab values.
3.Encourage the patient to stop smoking.
C.Pharmaceutical therapy:
1.Oral iron replacement:
a.Adult:
i.Begin 6-month trial of ferrous sulfate tablets 300 to 325 mg three times daily before meals or with orange juice 1 hour before meals. Food decreases iron delivery by 50%.
ii.Iron supplement (Slow Fe) one time-release capsule daily.
iii.Niferex 150 Forte one daily or more as required by follow-up iron levels.
2.Alternative drug therapy: Parenteral iron is indicated if the patient cannot tolerate or absorb oral iron or if iron loss exceeds oral replacement:
a.Iron dextran injection (Imferon).
b.Iron sorbitex injection (Jectofer):
i.Parenteral iron therapy is expensive.
ii.It is associated with significant side effects: anaphylaxis, phlebitis, regional adenopathy, serum sickness-type reaction, and staining of intramuscular (IM) injection sites. Test dose given prior to the first injection.
iii.Dose is based on the patient’s weight.
iv.Do not administer parenteral iron along with oral iron.
v.Use z-track method when administering injection. Iron stains the skin.
Follow-Up
A.Follow-up of adults is variable, depending on source of blood loss. Manage signs of anemia.
B.It is advisable to see the patient after 3 to 4 weeks, both to monitor the hematologic response and to answer questions about the medication, which may result in improved compliance.
C.If the patient’s Hgb level has increased by 1.0 g/dL in 3 to 4 weeks, continue iron supplementation for an additional 3 to 6 months. The Hct should return to normal after 2 months of iron therapy. However, keep taking iron supplements for another 6 to 12 months to replace the body’s iron stores in the bone marrow.
D.Determine the effectiveness of iron replacement therapy by checking CBC every 3 months for a year.
Consultation/Referral
A.Refer the patient to a physician for the following:
1.Hgb is not increased by 1.0 g/dL after 1 month of treatment.
2.The therapeutic trial should not be continued beyond 1 month because the Hgb concentration has not increased and patient compliance with recommended regimen is not a factor.
3.There is a steady downward trend in Hct despite treatment.
4.There is a significant drop in Hct over previous readings (rule out lab error first).
5.Lab findings show Hgb less than 9.0 g/dL or Hct less than 27%. Suspect underlying inflammatory, infectious, or malignant disease.
B.Refer the patient for nutrition consultation, if indicated.
Individual Considerations
A.Pregnancy:
1.Check Hct at initial prenatal visit, 28 weeks, and 4 weeks after initiating therapy.
2.Lab findings of Hgb greater than 13 g/dL and Hct greater than 40% may indicate hypovolemia. Be alert for signs of dehydration and preeclampsia.
3.Counsel the patient on proper diet and refer to a dietitian.
4.Recommend one to two iron tablets a day in addition to prenatal vitamins containing iron.
5.If unable to tolerate vitamins, recommend children’s Chewable Flintstones vitamins with iron, two orally, daily.
B.Adults:
1.Bleeding is the usual cause of anemia in adults. In adult men and postmenopausal women, bleeding is usually from the GI tract.
2.In premenopausal women, menstrual loss may be the underlying cause of anemia.
3.Smokers may have higher Hgb levels; therefore, anemia may be masked if standard Hgb levels are used.
C.Geriatrics:
1.The highest prevalence of anemia is found in elderly patients and long-term care residents. Geriatrics taking iron supplements to treat anemia often complain that it has made their constipation challenges worse.
2.Studies indicate that elderly patients with low Hgb/iron levels will benefit from a diet rich in iron dense foods and in some cases correct iron deficiencies. The highest bioavailability of iron is found in meats or meat products such as giblets, sausage, and liver. Good sources of plant-based dense iron foods are oat bran, black strap molasses, and legumes (chickpeas, lentils, dried peas). Encourage alternative measures of iron-dense foods for anemic geriatric patients and evaluate iron and Hgb levels after 4 to 6 weeks. If the Hgb level has not increased by 1.0 g/dL in 4 to 6 weeks, then begin a low-dose iron replacement synergistically with the iron-dense foods and continue to monitor lab levels per protocol. Some elderly patients have remained well-controlled with diet and iron supplement 3 days a week, which decreased the constipation side effect.
3.Research indicated that geriatrics with anemia related to pathophysiologic abnormalities or chronic disease (and not iron deficiency anemia) correlated with symptoms of depression, reduced sense of well-being, anxiety, energy limitations, social withdrawal, and reduction of quality of life. Those most effected with these secondary symptoms were geriatrics with advanced congestive heart failure (CHF) and those receiving palliative care. Be sure to implement a full psychosocial assessment with this specific population and refer as needed.
4.Undifferentiated Anemia of the Elderly (UAE). This unexplained phenomenon presents no evidence of B12/iron deficiency, iron studies normal, CR clearance greater than 30 mL/min, inflammatory markers (C-reactive protein [CRP]) are not elevated, and yet erythropoietin levels are low for the degree of anemia. This occurs in almost 1/3 of all anemic patients ≥ 65 years old.
It may be due to age-related decline of hematopoietic reserve, and at least 25% will evolve to myelodysplastic syndrome (MDS). Geriatric patients with UAE must be monitored for MDS because of the high risk for anemic complications, infections, and bleeding. Refer to hematologist if you suspect an MDS diagnosis.