APPROACH TO ANEMIA

Anemia is defined as either a reduction in number of red blood cells or a reduction in haemoglobin concentration in the blood( in comparision to the normal value for a given age group, sex and geographical location). Because anemia has its principal effect by decreasing the oxygen- carrying capacity of blood, it is best expressed in terms of hemoglobin concentration.

Table 1: Normal Hemoglobin/Hematocrit Values with Age and Pregnancy Age/Sex Hemoglobin g/dL Hematocrit % At birth 17 52 Childhood 12 36 Adolescence 13 40 Adult man 16 (±2) 47 (±6) Adult woman (menstruating) 13 (±2) 40 (±6) Adult woman (postmenopausal) 14 (±2) 42 (±6) During pregnancy 12 (±2) 37 (±6)

PRESENTATION AND SYMPTOMS Careful history and physical examination. Nutritional history related to drugs or alcohol intake. Family history of anemia should always be assessed. Bleeding, fatigue, malaise, dyspnoea, fever, weight loss, night sweats, and other systemic symptoms. physical examination: pallor, icterus, lymphadenopathy, splenomegaly petechiae forceful heartbeat, strong peripheral pulses, systolic "flow" murmur.

Table 57–1 Laboratory Tests in Anemia Diagnosis I. Complete blood count (CBC)   A. Red blood cell count     1. Hemoglobin     2. Hematocrit     3. Reticulocyte count   B. Red blood cell indices     1. Mean cell volume (MCV)     2. Mean cell hemoglobin (MCH)     3. Mean cell hemoglobin concentration (MCHC)     4. Red cell distribution width (RDW)   C. White blood cell count     1. Cell differential     2. Nuclear segmentation of neutrophils   D. Platelet count   E. Cell morphology     1. Cell size     2. Hemoglobin content     3. Anisocytosis     4. Poikilocytosis     5. Polychromasia II. Iron supply studies   A. Serum iron   B. Total iron-binding capacity   C. Serum ferritin III. Marrow examination   A. Aspirate     1. M/E ratioa     2. Cell morphology     3. Iron stain   B. Biopsy     1. Cellularity     2. Morphology

Table 57–2 Red Blood Cell Indices Index Normal Value Mean cell volume (MCV) = (hematocrit x 10)/(red cell count x 106)   90 ± 8 fL Mean cell hemoglobin (MCH) = (hemoglobin x 10)/(red cell count x 106)   30 ± 3 pg Mean cell hemoglobin concentration = (hemoglobin x 10)/hematocrit, or MCH/MCV 33 ± 2%

TREATMENT: Overiding principle is to reach to a diagnosis of anemia . Treatment target to the underlying cause. Anemia may be so acute and severe as to warrant immediate intervention such as blood transfusion.

IRON DEFICIENCY ANEMIA Iron deficiency is one of the most prevalent forms of malnutrition. Globally, 50% of anemia is attributable to iron deficiency approximately 841,000 deaths annually worldwide. Africa and parts of Asia bear 71% North America represents only 1.4%

IRON CIRCULATION

Iron absorbed from the diet or released from stores circulates in the plasma bound to transferrin, the iron transport protein. Interacts with specific transferrin receptors on the surface of marrow erythroid cells. The complex is internalized where the iron is released at the low pH. The iron is then made available for heme synthesis . The transferrin-receptor complex is recycled to the surface of the cell, where the bulk of the transferrin is released back into circulation and the transferrin receptor reanchors into the cell membrane. Within the erythroid cell, iron in excess of the amount needed for hemoglobin synthesis binds to a storage protein, apoferritin, forming ferritin. The iron incorporated into hemoglobin subsequently enters the circulation as new red cells. In a normal individual, the average red cell life span is 120 days

Table 103-1 Body Iron Distribution   Iron Content, mg Adult Male, 80 kg Adult Female, 60 kg Hemoglobin Myoglobin/enzymes Transferrin iron Iron stores 2500 500 3 600–1000 1700 300 0–300

Table 103-2 Causes of Iron Deficiency Increased Demand for Iron    Rapid growth in infancy or adolescence   Pregnancy   Erythropoietin therapy Increased Iron Loss    Chronic blood loss   Menses   Acute blood loss   Blood donation   Phlebotomy as treatment for polycythemia vera Decreased Iron Intake or Absorption    Inadequate diet   Malabsorption from disease (sprue, Crohn's disease)   Malabsorption from surgery (postgastrectomy)   Acute or chronic inflammation

Table 103-4 Diagnosis of Microcytic Anemia Tests Iron Deficiency Inflammation Thalassemia Sideroblastic Anemia Smear Micro/hypo Normal micro/hypo Micro/hypo with targeting Variable SI <30 <50 Normal to high TIBC >360 <300 Normal Percent saturation <10 10–20 30–80 Ferritin (g/L) <15 30–200 50–300 Hemoglobin pattern on electrophoresis Abnormal with  thalassemia; can be normal with thalassemia

PRESENTATION /SIGNS AND SYMPTOMS: Bleeding, fatigue, malaise, dyspnoea, dysphagia, fever, weight loss, night sweats, and other systemic symptoms. physical examination: pallor, icterus, angular stomatitis, oesophageal webs, lymphadenopathy, koilonychia/platynychia, splenomegaly, petechiae, forceful heartbeat, strong peripheral pulses, systolic "flow" murmur

TREATMENT OF IRON DEFICIENCY ANEMIA Blood transfusion: reserved for individuals who have symptoms of anemia, cardiovascular instability, continued and excessive blood and require immediate intervention. Parenteral iron therapy: Body weight (kg) x 2.3 x (15–patient's hemoglobin, g/dL) + 500 or 1000 mg (for stores). unable to tolerate oral iron whose needs are relatively acute iron dextran sodium ferric gluconate (Ferrlecit) iron sucrose (Venofer)

Oral iron therapy: asymptomatic patient with established iron-deficiency anemia. Up to 300 mg of elemental iron per day is given, usually as three or four iron tablets (each containing 50–65 mg elemental iron) given over the course of the day. Ideally, oral iron preparations should be taken on an empty stomach, since food may inhibit iron absorption. The goal of therapy is not only to repair the anemia, but also to provide stores of at least 0.5–1 g of iron. Sustained treatment for a period of 6–12 months after correction of the anemia will be necessary to achieve this.