Читать книгу Laboratory Assessment of Nutritional Status: Bridging Theory & Practice - MARY LITCHFORD - Страница 15

Anemias due to a deficient erythropoiesis include microcytic anemias, normochromic-normocytic anemias and macrocytic anemias. All of these anemias are characterized by low hemoglobins and hematocrits (Blackwell, 2001). The distinction is made by examining the MCV (Coulter, 1991). This test provides the average size of the patient’s red blood cell. In microcytic anemias the heme or globin synthesis is deficient or defective resulting in a lower than normal MCV. In normocytic anemia the bone marrow failure prevents the erythroid mass from expanding as needed, but the volume is normal, so the MCV is normal. Megaloblastic erythropoiesis results when DNA or RNA synthesis is impaired. The MCV then exceeds normal values (Blackwell, 2001). Other tests used to evaluate erythropoiesis include reticulocyte count, red blood cell count, erythrocyte count and red blood cell width (RDW).