Anemia Dr. Meg-angela Christi M. Amores

What is Hematopoeisis? It is the process by which the formed elements of the blood are produced Erythropoeisis: production of erythrocytes (red blood cells) Regulatory hormone: EPO (erythropoeitin) – kidney

Erythropoeisis Critical elements: – EPO production – iron availability – the proliferative capacity of the bone marrow – effective maturation of red cell precursors

Anemia Often recognized by abnormal screening tests Less commonly presents signs and symptoms unless advanced Acute anemia – due to blood loss or hemolysis – If acute blood loss, hypovolemia results Hypotension is the issue, not anemia 10 – 15% blood loss- signs of vascular instability >30% - postural hypotension, tachycardia >40% - hypovolemic shock (confusion, dyspnea, diaphoresis, hypotension, tachycardia)

Anemia Acute anemia – due to blood loss or hemolysis – Acute hemolysis Symptoms: fatigue, loss of stamina, breathlessness, and tachycardia (particularly with physical exertion) Most often only occurs when advanced (hgb <7 mg/dL)

Approach to patient History: – Nutritional (food, drugs, alcohol) – Family history – G6PD deficiency PE: – Findings of infection – blood in the stool, lymphadenopathy, splenomegaly, or petechiae – forceful heartbeat, strong peripheral pulses, and a systolic "flow" murmur

Pallor skin and mucous membranes may be pale if the hemoglobin is <80–100 g/L (8–10 g/dL) If palmar creases are lighter in color than the surrounding skin when the hand is hyperextended, the hemoglobin level is usually <80 g/L (8 g/dL)

Laboratory Evaluation

Normal Hgb and Hct levels

CBC Components of CBC help in the classification of anemia: – Microcytosis - reflected by a lower than normal MCV (<80) – Macrocytosis - high values (>100) of MCV – MCH and MCHC reflect defects in hemoglobin synthesis - hypochromia

Peripheral blood smear provides important information about defects in red cell production the blood smear also reveals variations in cell size (anisocytosis) and shape (poikilocytosis)

Reticulocyte count key to the initial classification of anemia Normally, the reticulocyte count ranges from 1–2% and reflects the daily replacement of 0.8–1.0% of the circulating red cell population reticulocyte count provides a reliable measure of red cell production In the face of established anemia, a reticulocyte response less than two to three times normal indicates an inadequate marrow response.

Tests of Iron Supply and storage serum iron TIBC percent transferrin saturation serum ferritin is used to evaluate total-body iron stores

Bone Marrow examination Indications: – patients with hypoproliferative anemia and normal iron status – can diagnose primary marrow disorders such as myelofibrosis, a red cell maturation defect, or an infiltrative disease

Functional Classification 1.marrow production defects (hypoproliferation) 2.red cell maturation defects (ineffective erythropoiesis ) 3.decreased red cell survival (blood loss /hemolysis)

Hypoproliferative Anemia 75% of all anemia reflects absolute or relative marrow failure Majority are due to mild to moderate iron deficiency or inflammation can result from marrow damage, iron deficiency, or inadequate EPO stimulation normocytic, normochromic red cells Key diagnostic tool: IRON studies

Hypoproliferative Anemia anemia of acute or chronic inflammation – serum iron (low), TIBC (normal or low), percent transferrin saturation (low), and serum ferritin (normal or high) mild to moderate iron deficiency – (low serum iron, high TIBC, low percent transferrin saturation, low serum ferritin)

Maturation disorders anemia with an inappropriately low reticulocyte production index, macro- or microcytosis on smear, and abnormal red cell indices ineffective erythropoiesis that results from the destruction within the marrow vitamin B 12 or folic acid deficiency, drug damage, or myelodysplasia

Blood Loss / Hemolytic Anemia Red blood cell indices >2.5x the normal stimulated erythropoiesis typically normocytic or slightly macrocytic Hemolysis – least common form of anemia – present in different ways – paroxysmal nocturnal hemoglobinuria – Hemoglobinopathies – hereditary spherocytosis

Treatment Severe anemia: red cell transfusions acute or gradual onset: determined by the documented cause(s) of the anemia important to evaluate the patient's iron status fully Chronic kidney disease: Recombinant EPO