Anemia Flashcards
Conditions that can suppress RBC production
-Renal insufficiency
-Cancer
-Myelodysplasia
-Chronic inflammatory disease
WHO Definition of Anemia
- Hemoglobin level <13 g/dL (males)
- Hemoglobin level <12 g/dL (females
Anemia can be a result of a number of conditions
-Nutritional deficiencies
-Systemic disease
-Bone marrow disease
-Underlying immunologic disorder
-Or when there is something intrinsically wrong with the RBC itself
Normal Erythropoiesis
-Circulating erythrocyte has an average life span of 110-120 days
-More than 90% of the protein content is the oxygen-carrying molecule hemoglobin
-Hemoglobin is made up by four protein molecules or globulin chains that are connected together.
-The normal adult hemoglobin (Hbg) molecule contains two alpha-globulin chains and two beta-globulin chains.
-The globin chains are held together by HEME molecules
-Embedded in the HEME molecule is iron; which gives red blood cell it’s RED COLOR
The most important role of the red blood cell is to
-TRANSPORT OXYGEN FROM THE LUNGS
-To the tissues throughout the body
Erythrocyte maturation
-RBCs are derived from bone marrow where it undergoes 4 different maturation stages until is develops into a reticulocyte (process takes 2-3 days)
-Late maturation stage of the reticulocyte takes place in peripheral blood where it becomes an erythrocyte
Increased Reticulocyte counts
An increased reticulocyte count (or reticulocytosis) is a reflection of the body’s attempt at trying to maintain homeostasis when there is decreased RBC production or shortened life span.
Erythroid specific growth factor-erythropoietin
(EPO)
-Sensed by the juxtaglomerular apparatus of the kidney
-EPO is the primary regulatory hormone for erythropoiesis
-Under normal conditions, RBC mass is nearly constant because of the EPO feedback loop
-When the kidney senses hypoxia, it releases the hormone ERYTHROPOIETIN
-Erythropoietin is the chemical messenger that tells the BONE MAROW to produce more red cells BECAUSE THE BODY IS STARVING FOR OXYGEN
Presenting Symptoms
-Fatigue, weakness, pallor, dizziness
-Dyspnea, tachypnea, O2 desaturation
-Tachycardia, palpitations, hypotension, arrhythmias, chest pain
Physical Exam
-Pallor (usually occurs with hgb <8)
-Confusion, paresthesia
-Tachycardia/Tachypnea
-Systolic murmur
-splenomegaly (hemolysis)
-Orthostatic hypotension
-signs/symptoms of CHF
-Jaundice (hemolysis)
Anemia-Probable etiology
-Poor production of RBC
-Increased RBC destruction
-Blood loss
Poor RBC production
-Nutritional deficits-Folate, iron, B-12
-Bone marrow disorder
-Bone marrow suppression
-Low levels of hormones needed to
stimulate RBC production (EPO, thyroid hormone, androgens)
-Chronic disease/inflammation associated with malignant, infectious, inflammatory disorders
Increased RBC destruction
-Hemolysis
-RBC lifespan is shortened <100 days.
Blood loss-chronic
-Bleeding—loss of RBCs—depletion of iron stores—anemia
Usually occurs with blood loss of:
> 1200 ml for males
> 600 ml for females
Anemia-The Cause
-Classified based upon erythrocyte morphology
-Size, shape, color, inclusions
-CBC, Peripheral blood smear-Morphology, Retic count-bone marrow integrity
Retic Count
Retic count (0.5%-1.5%) shows to be elevated in hemolytic anemia hemorrhage, and Chronic renal failure; decreased in AA, marrow suppression,
CBC
-Hgb-concentration
-HCT-Packed red cell volume-crucial for certain procedures
-RDW-RBC distribution width-measures the RBC size
-MCV (mean corpuscular volume)-average volume of an erythrocyte
-MCH (Mean corpuscular hemoglobin)-average weight (content) of hgb in an average erythrocyte
-MCHC (Mean corpuscular hemoglobin concentration)- (the average concentration of hemoglobin per unit volume of erythrocytes)
Normal values of CBC
-Hgb: Males (12.7-17), Female (11.6-15.6)
-RBC (x 10^12/L): Males (4.0-5.6); Females (3.8-5.2)
-MCV (x 10^12/L): Males (81.2-101.4), Females (81.1-99.8)
-RBC distribution width %: Male (11.8-15.6), Females (11.9-15.5)
-Platelets (x10^9/L): Males (143-332), Female (169-358)
-WBC (x10^9/L); Males (3.6-9.2), Females (3.5-10.8)
Decreased Retic Count
-Bone marrow disease
-B-12 deficiency
-Folate deficiency
-Iron deficiency
Increased Retic Count
-Blood loss
-Hemolytic anemia
-Post-anemia Tx-response
High MCV
-Macrocytic anemia