Red blood cell disorders Flashcards

Question

Classifications of Anemias

Answer 1

Rate of development of RBC's: Acute – severe, rapid blood loss (hemorrhage) Chronic – gradual blood loss or other chronic condition that results in anemia Morphology (shape): Macrocytic – large RBCs Normocytic – normal size RBCs Microcytic – small RBCs Hemoglobin content: Hyperchromic – too much Hgb Normochromic – normal amounts of Hgb Hypochromic – too little Hgb Type of defect or etiology: Production defect – lack of necessary building blocks to make RBCs Destruction defect – bone marrow destruction or hemolysis Genetic defects in Hemoglobin – sickle cell anemia

Answer 2

Microcytic-Hypochromic: (small RBC'S)- with (not enough hemoglobin) causes: Iron deficiency Thalassemia Chronic systemic diseases Microcytic-Normochromic: (small RBC's) with (normal amounts of hemoglobin) causes: Chronic systemic diseases

Answer 3

NORMOCYTIC- Normochromic: (RBC'S are normal size but the count is low) with (normal hemoglobin amounts) causes: Anemia of chronic disease Acute blood loss Hemolytic anemia Renal failure Liver disease Hypothyroidism Sickle cell anemia Hypersplenism NORMOCYTIC-hypochromic: (RBC ow count with not enough hemoglobin) causes: Lead poisoning (plumbism) Chronic systemic diseases Normocytic-hyperchromic (low RBC with too much hemoglobin) hereditary spherocytosis

Answer 4

macrocytic-Normochromic: Folic acid deficiency Vitamin B12 deficiency Alcoholism- affects liver Chronic liver disease Hypothyroidism Aplastic anemia & myelodysplastic syndromes Drug-induced (chemotherapy) macrocytic-hypochromic: Some macrocytic anemias with superimposed iron deficiency

Answer 5

Inadequate or inaccessible iron Lack of folic acid Lack of vitamin B12 Lack of globulin Bone marrow disease (e.g., leukemia) Deficiency of erythropoietin (as in renal failure, kidneys cant make this protein)

Answer 6

Causes: (suppression of bone marrow) Idiopathic Radiation Chemotherapy Labs: Normocytic Normochromic ↓ Reticulocyte count signs and symptoms: hypoxemia decrease in bone marrow function (myelosupression) which can lead to increased infection and bleeding risk Treatments: Stop drugs Transfusions Bone marrow transplant

Answer 7

Causes: ↓ intake ↓ absorption Chronic blood loss Labs: Microcytic Hypochromic ↑ Total Iron Binding Capacity (TIBC) ↓ Ferritin signs and symptoms: hypoxemia treatment: Iron – dietary supplement, parenteral iron

Answer 8

Microcytic (↓ MCV) Hypochromic (↓ MCHC) MOST COMMON cause of anemia (all ages): ↓ production of Hgb because of a ↓ in availability of Iron (Fe) MOST COMMONLY due to Chronic blood loss: Menorrhagia: heavy menstrual bleeding, often with clots for 7-10 days (often thought to be normal) Occult GI loss: up 50-75 mL of blood per day Even a well-balanced diet & increased Fe uptake by transferrin CANNOT offset these losses

Answer 9

70% of iron in body found in Hgb of RBCs; 30% stored in form of ferritin & hemosiderin Iron is necessary for production of hemoglobin Test usually measures iron bound to transferrin Provides indirect measure of rate of delivery to tissues Affected by: hemolysis, time of day, transfusion, menstruation, and supplementation Of little diagnostic value by itself

Answer 10

Iron-phosphorous-protein complex that contains ~23% iron; formed in intestinal mucosa by union of ferric iron with the protein apoferritin Form in which iron is stored in the tissues esp. reticuloendothelial cells of the liver, spleen, & bone marrow Amount of ferritin is directly affected by the total body iron stores Good marker for iron deficiency anemia Widely distributed in tissues: thus ↑ serum levels in blood from tissue damage (inflammation, malignancy, hepatitis) false elevation Treatments: Administration of iron supplements (takes awhile) ↑ level 2-3 weeks for oral; within 24 hours parenteral Acutely ill or chronically ill may not be as useful Not affected by blood transfusion

Answer 11

Globulin in the blood that binds & transports iron 1/3 bound with iron & 2/3 reserve; ½ life = 1 wk Can be measured directly or estimated from the Total Iron Binding Capacity (TIBC) Transferrin (mg/dL) = [0.8 x TIBC (in mg/dL)] - 44 TIBC = maximum iron-binding capacity of transferrin and other iron binding globulins Some labs do not perform – more an indication of liver function & nutrition Transferrin is inversely related to iron stores: ↓ stores means ↑ transferrin ↑ stores means ↓ transferrin Transferrin also affected by inflammation, loss of protein, nutritional status, liver disease

Answer 12

The percentage of transferrin and other mobile iron-binding proteins that are saturated with iron The ratio of serum iron to iron binding capacity Transferrin saturation (%) = [(serum iron level) / (TIBC)] x 100% Normal = 20-50% Iron deficiency associated with low saturation (<15%) Iron overload and hemochromatosis (too much iron in the body) are associated with high saturation (>50% F; >62% M)

Answer 13

0 – 20 mg Fe in average diet Only 1-2 mg of Fe absorbed from intestines (primarily duodenum & upper jejunum) Menstruating Females: lose 30 mg Fe with each period Pregnancy & Childbirth: loss of 650 mg to fetus & intrapartal bleeding Storage: 500 – 1500 mg stored as ferritin & hemosiderin in reticuloendothelial cells of macrophage system (liver, spleen, & bone marrow) & muscle as myoglobin

Answer 14

Same as for ALL anemias ALSO includes: (although mechanisms poorly understood) Brittle, spoon-shaped nails Glossitis – smooth, red, sore tongue Web in upper esophagus Pica – habitual eating of non-nutritive substances e.g., clay, laundry starch, ice, paint

Answer 15

Correct underlying cause (e.g., bleeding) Ferrous sulfate 300 mg QD – TID given with meals or shortly after because very irritating Give liquid form with straw to prevent staining of teeth IM 🡪 MUST use Z-track technique & give deep in muscle Reticulocytosis in 4-5 days Therapy continued for months to replenish stores Transfusion if severe

Answer 16

Impaired synthesis of DNA in RBC precursors in bone marrow MOST OFTEN d/t Vitamin B12 deficiency or folic acid deficiency RBCs large = macrocytic (↑ MCV) with a ↓ lifespan & few in number Often seen in combination with ↓ WBC, ↓ PLT, ↓ RETIC

Answer 17

Must be supplied in food Meat, eggs, milk, cheese Absorbed in terminal ileum Absorbed ONLY when in complex with INTRINSIC FACTOR (a mucoprotein secreted by parietal cells of gastric mucosa) Large store in liver decreases from dietary inadequacy or decreased in intrinsic factor does not produce anemia for years Other causes: DECREASED absorption from defects in ileum, consumption by parasites or unusual bacteria

Answer 18

Vitamin B12: 100-700 pg/ml Interfering factors: increases seen in pregnancy, oral contraception, high dose vitamins A and C, smoking Folic Acid (Folate): 2-20 ng/ml Interfering factors: folic acid antagonists, hemolysis, transfusion

Answer 19

Intrinsic Factor is a glycoprotein manufactured by the parietal cells of the gastric mucosa Function = bond with ingested cobalamine (vitamin B12) and then adhere to receptor sites in the distal ileum where it is absorbed into the blood then transported to the liver for storage or to the bone marrow for erythropoiesis Pernicious anemia: Inadequate production of intrinsic factor Interference with bonding of intrinsic factor-cobalamine (caused by type 1 blocking antibody) Interference with bonding of intrinsic factor-cobalamine complex at the ileal receptor sites (caused by type 2 binding antibody)

Answer 20

Causes: ↓ intake ↓ intrinsic factor ↑ ETOH use Labs: Macrocytic Normochromic ↓ B12 signs and symptom: Hypoxemia Neurologic symptoms: paresthesias Treatments: ↑ Vitamin B12 in diet Parenteral vitamin B12

Answer 21

Pernicious Anemia Result of autoimmune disease against stomach’s parietal cells (usu. after age 40) Total gastrectomy removes source of intrinsic factor Vegetarian diet often low in Vitamin B12 Chronic alcoholism 🡪 poor diet & nutrition + impaired absorption Sprue & celiac disease 🡪 malabsorption syndromes Resection of ileum 🡪 interferes with absorption Increased requirements as in pregnancy

Answer 22

Insidious: S/S of hypoxemia ALSO: Premature grey hair Vitiligo Low blood pressure Lemon-yellow skin color Low grade fever Splenomegaly Yellow-blue color blindness NEUROLOGIC: Early: Inability to perform fine movements Loss of vibratory sense & 2 point discrimination Progressive: Paresthesias, weakness, uncoordination, ataxia, personality changes Late: Urinary / fecal incontinence, spastic paralysis, confusion psychosis

Answer 23

Must be supplied in food (if supplement – cyanocobalamin) US RDA = 3 μg Meat, eggs, milk, cheese Absorbed in terminal ileum Absorbed ONLY when in complex with INTRINSIC FACTOR (a mucoprotein secreted by parietal cells of gastric mucosa) Large store in liver 🡪 dietary inadequacy or ↓ in intrinsic factor does not produce anemia for years Other causes: ↓ absorption from defects in ileum, consumption by parasites or unusual bacteria

Answer 24

Causes: ↓ intake ↑ ETOH use ↑ demand (pregnancy & lactation) Drugs: folic acid antagonists Labs: Macrocytic Normochromic ↓ Serum Folate: signs and symptoms: Hypoxemia No neurologic symptoms Tx: ↑ intake, diet supplements tretment: increase intake and diet supplements

Answer 25

Causes: Trauma Surgery Labs: Normocytic Normochromic ↑ Reticulocyte count S/S: Volume depletion ↓ BP & ↑HR 🡪 shock Tx: Hemostasis Oxygen Transfusion

Answer 26

Causes: GI bleed (ulcer) Menstruation Labs Microcytic Hypochromic ↑ Reticulocyte count S/S: Hypoxemia Tx: Treat cause Iron therapy

Answer 27

Very common—2nd most common cause after iron deficiency Seen with malignancy, chronic infection or inflammation (e.g., rheumatoid arthritis) Typically normocytic, normochromic or slightly hypochromic RBC survival shortened, but no compensatory ↑ in production R/T hyperactive immune system resulting in ↑ destruction without ↑ production Reticulocyte count low and does not respond to any known therapy

Answer 28

Defined as an abnormally high total red cell mass Hct >50% Often an accompanying rise in WBC and PLT Relative = Hct rises with loss of plasma volume Absolute Primary = polycythemia vera – commonly seen in men between 40 and 60; a proliferative disorder Secondary = arises from an increase in erythropoietin – usually as compensation from chronic hypoxia (high altitudes, heart and lung disease, smoking) ; also tumors

Answer 29

Manifestations are related to the increased blood volume and viscosity: Viscosity can interfere with cardiac blood flow Hypertension Venous stasis Thromboembolism

Answer 30

If primary, focus is to reduce blood viscosity – often with periodic phlebotomy, drug therapy, or bone marrow transplant If secondary to hypoxia, must correct that problem, i.e. with oxygen

Red blood cell disorders Flashcards

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