Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ NORMAL HEMOGLOBIN (HGB) AND MEAN CORPUSCULAR VOLUME (MCV) BY AGE ++ Red blood cell (RBC) parameters vary with age, race, and gender (Table 15-1). Lower limit of normal (3rd percentile) Hgb from age 1-10 years = 11 + (0.1xAge). Lower limit of normal (3rd percentile) MCV from age 1-10 years = 70 + Age. ++Table Graphic Jump LocationTABLE 15-1.Normal Hemoglobin (Hgb) and Mean Corpuscular Volume (MCV) by AgeView Table||Download (.pdf) TABLE 15-1.Normal Hemoglobin (Hgb) and Mean Corpuscular Volume (MCV) by Age AGE HGB (G/DL) MCV (FL) Birth 14–20 100–120 2 month 10–13 78–94 6 month 10.5–13 69–82 1 year 10.5–13.5 70–86 2–12 years 11.5–15.5 70–90 12–18 years 12–16 78–102 +++ ANEMIA +++ DEFINITION ++ Physiological: Hgb level too low to meet cellular oxygen demands. Practical: Hgb level 2 SD below mean for age, gender, and race. +++ CLASSIFICATION ++ Based on red blood cell (RBC) size, also known as MCV (see Table 15-2). Classification is based on mechanism: Blood loss or RBC sequestration (e.g., trauma). RBC destruction (high reticulocyte count) (e.g., ABO incompatibility in newborn). Decreased RBC production (low reticulocyte count) (e.g., aplastic anemia). Hemolytic anemia is mediated by either intrinsic RBC defects or disorders extrinsic to the red cell (see Figure 15-1). ++Table Graphic Jump LocationTABLE 15-2.AnemiasView Table||Download (.pdf) TABLE 15-2.Anemias MCV ANEMIA LABS Microcytic Iron deficiency Thalassemia Anemia of chronic disease Sideroblastic anemia Some hemoglobinopathies (HbC, HbE, unstable Hbs) Low ferritin, high TIBC, high platelet count Normal to high RBC count, microcytosis disproportionate to anemia, normal iron studies High ferritin and low TIBC Normal or high ferritin Abnormal hemoglobin electrophoresis Normocytic Acute blood loss Hemolytic anemia Anemia of chronic disease Hemoglobinopathy Transient erythroblastopenia of childhood High bilirubin/LDH Very low reticulocyte count Macrocytic Hemolytic Liver disease, hypothyroidism Drug effect (e.g. hydroxyurea) Diamond Blackfan anemia Aplastic anemia and myelodysplastic syndromes High bilirubin/LDH Abnormal T4 /TSH Very low reticulocyte count Very low reticulocyte count and other cell lines down Macrocytic with megaloblastic bone marrow Folate deficiency B12 deficiency Low serum/RBC folate, high homocysteine High serum cobalamin, methylmalonic acid and homocysteine ++ FIGURE 15-1. Hemolytic anemias. Graphic Jump LocationView Full Size||Download Slide (.ppt) +++ PATHOPHYSIOLOGY ++ Less oxygen transport and decreased blood volume lead to clinical consequences. Physiological adaptations include: Increased heart rate and stroke volume (increases cardiac output). Increased 2,3 diphosphoglycerate (DPG) levels (leads to decreased O2 affinity of Hgb and better O2 delivery). Vasodilatation (expands blood volume). +++ SIGNS AND SYMPTOMS ++ Somnolence, light-headedness, headache, and easy fatiguability. Exertional dyspnea, palpitations, sinus tachycardia, and flow ... Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Download the Access App: iOS | Android Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.