Discussion response

Respond to three of your classmate’s posts with substantive comments or questions. You must submit your discussion and participate with your peers’ posts by the deadline
 Anemia is a commonly diagnosed condition by providers in the primary care setting (Nagao & Hirokawa, 2017). Anemia is classified as a decrease in the quality/quantity of hemoglobin or a decrease in the overall circulation of red cell mass in the body, with tissue hypoxemia as the main physiologic manifestation of this disease process (Woo & Robinson, 2020). Anemia is classically defined as a hemoglobin (Hb) count of less than 13 g/L in men, less than 12 g/L in non-pregnant women, and less the 11 g/L in pregnant women and the elderly (Nagao & Hirokawa, 2017)(Lanier et al., 2018). Using the differential diagnosis is necessary to classify the type of anemia based on the red cell indices of Wintrobe: red blood cell count, hemoglobin concentration, and hematocrit (Nagao & Hirokawa, 2017).  
Recognizing the signs and symptoms of anemia is also an important step. Acute presentations, secondary to volume loss include lightheadedness, syncope, and hypotension (Lanier et al., 2018). Chronic symptoms, which have the potential to be asymptomatic may present in severe cases to include: a decreased oxygen-carrying capacity, weakness, fatigue, shortness of breath, and worsening comorbid conditions (Lanier et al., 2018). Common risk factors for anemia should also be taken into consideration, especially in the older adult populations: chronic alcohol use, malnutrition, chronic kidney disease, liver disease, myelodysplastic disorders, gastrointestinal bleeding, cancer, and androgen deficiency (Lanier et al., 2018).
Once a diagnosis of anemia is suspected, a complete blood count with differential should be obtained (Lanier et al., 2018). Results indicating anemia would require further studies and tests to guide treatment. A mean corpuscular volume test would be used to identify the anemia as microcytic (less than 80 fL), normocytic (80 to 100 fL), or macrocytic (greater than 100 fL) (Lanier et al., 2018). Microcytic and normocytic anemias tend to be more common in the older population, with iron deficiency being the common microcytic anemia, and chronic diseases and diseases of unknown origin as being more associated with normocytic anemias (Lanier et al., 2018). A serum ferritin level will help to differentiate the type of anemia; a level less the 19 ng per mL is highly indicative of iron deficiency anemia, but an iron deficiency can still be present in individuals with higher serum ferritin levels (Lanier et al., 2018). A serum transferrin receptor-ferritin index could be used to help differentiate between iron deficiency anemia and other types; an index of greater than 1.5 supports a diagnosis of iron deficiency anemia (Lanier et al., 2018). The use of a fecal occult test would also be recommended for iron deficiency anemias, with endoscopic evaluation if fecal occult blood is noted (Lanier et al., 2018).  If iron deficiency anemia is an excluded diagnosis, a chronic disease, such as chronic kidney disease tends to be the most likely cause in the older population (Lanier et al., 2018). A serum creatinine and glomerular filtration (GFR) test would be indicated; a GFR less than 60 would indicate chronic kidney disease; a GFR greater than 60 could be indicative of another type of anemia or chronic disease with further testing or referrals needed (Lanier et al., 2018).
A serum ferritin level greater than 100 ng per mL could be indicative of macrocytic anemia (Lanier et al., 2018). Using a peripheral blood smear and reticulocyte count should be the initial step for the evaluation of macrocytic anemia (Lanier et al., 2018). If abnormalities are noted in the blood smear, a myelodysplastic syndrome or malignancy would diagnosis would be considered and a referral to a hematologist would be warranted (Lanier et al., 2018). If the reticulocyte count is elevated more than 2%, it is associated with hemolysis, hypersplenism, or recent blood loss (Lanier et al., 2018). Increased levels of indirect bilirubin and lactate dehydrogenase, a decreased level of haptoglobin, and a positive Coombs test suggest the presence of hemolytic anemia and hemolysis (Nagao & Hirokawa, 2017)(Lanier et al., 2018). A decreased reticulocyte count of less than 2% would occur in folate and vitamin B12 deficiency (Lanier et al., 2018). The use of serum folate and vitamin B12 levels would be helpful to differentiate between the deficiencies (Nagao & Hirokawa, 2017). If the serum vitamin B12 levels are less than 200 pg/mL, a vitamin B12 deficiency is likely; if levels are between 200-300 pg/mL metabolite testing should be used to help rule out the deficiencies. Serum concentrations of homocysteine and methylmalonic acid (MMA) are elevated in B12 deficiency, whereas only homocysteine is elevated in folate deficiency (Nagao & Hirokawa, 2017). A serum folate deficiency will be ruled out if the serum level is greater than 4 ng/mL and diagnostic for folate deficiency if less than 2 ng/mL (Nagao & Hirokawa, 2017). The absence of an elevated reticulocyte count could be indicative of possible alcoholism, liver dysfunction, hypothyroidism, or myelodysplastic syndrome (Nagao & Hirokawa, 2017).
Treatment for the anemias is guided by the underlying diagnosis. If significant concern for anemia is noted with a Hb level below 7 g/dL, then a hospital admission and blood transfusion should be considered (Lanier et al., 2018). Iron replacement therapy can be used as treatment and a diagnostic discriminator for iron deficiency anemia; 325 mg oral dosing three times a day on an empty stomach for maximum absorption, liquid iron in doses as low as 15 mg with orange juice for optimal absorption, or parenteral iron infusion if other routes are not tolerated (Lanier et al., 2018). Vitamin B12 and folate can be replaced with oral therapy, 1 mg per day, parenteral infusions are also effective forms of treatment (Lanier et al., 2018). Referrals may also be needed for other underlying chronic conditions or malignancies (Lanier et al., 2018). Bone marrow examinations would be used for patients with abnormal cells or for patients that did not respond to other treatments or vitamin replacement (Nagao & Hirokawa, 2017).
References
Lanier, J. B., Park, J. J., & Callahan, R. C. (2018). Anemia in Older Adults. American Family
            Physician, 98(7), 437442.
McCance, K. L., & Huether, S. E. (2019). Alterations of erythrocyte, platelet, and hemostatic
            function. In K. L. McCance & N. S. Rote (Eds.), Pathophysiology: The biologic basis
            for disease in adults and children. (5th ed., pp 926-962). Elsevier.
Nagao, T., & Hirokawa, M. (2017). Diagnosis and treatment of macrocytic anemias in adults.
            Journal of General and Family Medicine, 18(5), 200204.
            https://doi.org/10.1002/jgf2.31