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133 Cards in this Set
- Front
- Back
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Common presentation of anemia |
-easy fatigability
-faintness -palpitations -tinitis -glossitis -dyspnia on exertion -vertigo -HA -ulcers of buccal mucosa |
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Physical signs of anemia
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-pallor
-rapid pulse -low BP -slight fever -systolic murmor |
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Anemia definition
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-reduced number of circulating erythroctes (RBCs)
-lowering of the concentration of hemoglobin -reduction in hematocrit |
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Primary physical defect of anemia
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-reduction in the oxygen carrying capacity of the blood resulting in hypoxia
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Anemia may indicate underlying disease such as..
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-chronic hemorrhage
-neoplasm -chronic infection -renal failure |
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Erythron
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-composite function of all erythroid tissue in the body
-encompasses production of cells, release of cells, destruction of cells |
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Earliest red cell production occurs in...
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-primative mesenchymal cells called blood islands
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Blood islands
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-primative mesenchymal cells where earliest RBC production occurs
-found in fetal yolk sac in 3rd or 4th week of embryonic life -represent the earliest hemoglobin synthesizing cells -migrate to liver, spleen, lymph nodes, and thymus in third month of life |
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RBC production in adults occurs in..
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-medullary within the bone marrow
-mostly in flat bones (sternum, ribs, skull, vertebrae, epiphysial regions of long bones) |
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RBC production occurs in extra-medullary sites...
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-before birth
-with pathological conditions after birth (reversion back to more primative cell production bc normal mechanisms are not functioning properly) |
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In times of increased cell demand, hematopoiesis may develop in..
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-shafts of long bones
-e.g. individuals with chronic hemolytic disease like thalassemia or sickle cell -may cause bone pain |
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Bone marrow consists of a mixture of...
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-fat (yellow marrow)
-hematopoetic marrow (red marrow) |
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Red marrow is composed of..
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-dense aggregates of cells lying alongside tiny, microscopic, open vascular spaces called sinusoids
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Within the sinusoids, RBCs develop through a series of well defined stages:
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-erythroblasts (rubriblasts)
-prorubricytes -rubricytes -metarubricytes |
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Cell release at medullary sites
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-release cells into blood stream when they are mature
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Cell release at extramedullary sites:
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-release cells in all stages (not just mature cells)
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Presence of immature cells (RBC or WBC) in the peripheral blood indicates...
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-hematoposiesis is taking place in extra-medullary sites
-disruption in bone marrow (leukemia, or space occupying lesions such as infection, cancer, granulomas, mylofibrosis) |
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Normal RBC life span
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120 days
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hemolytic anemia
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-reduced life span of RBC
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Causes of hemolytic anemia (extrinsic damage)
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-immunological reactions (antigen antibody rxns)
-trauma (mechanical heart valves) -physical stresses such as burns, pH changes, osmostic imbalance -"march" (feet slamming against ground found in soldiers in WWII, marathoners) |
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Causes of hemolytic anemia
(instrinic causes) |
-defects in hemoglobin synthesis (thalassemia, hemoglobinopathies such as sickle cell)
-invasion by animal parasites (malaria) -enzyme defects that may lead to poor hemoglobin synthesis |
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Decrease in survival of RBC (hemolytic anemia) can effect other component of the erythron such as..
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-increase in production
-alter normal release mechanism |
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Changes in the erythron due hemolytic anemia will manifest in...
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peripheral blood smear
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Types of anemias
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1. hypochromic, microcytic
2. macrocytic 3. normocytic, normochromic |
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Hypochromic microcytic anemia
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-erythrocytes do not posses sufficient hemoglobin
(tiny cells so they can't hold enough hemoglobin) -MOST COMMON |
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Common variants of hypochromic microcytic anemia
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-iron deficiency
-thalassemia syndromes -hemoglobinopathies (e.g. sickle cell) -sideroblastic anemia -iron-loading anemias -refractory anemias |
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Most common form of anemia is...
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iron deficiency anemia (type of hypochromic microcytic anemia)
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macrocytic anemias
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-MCV is too big
-may have oval macrocytes or round macrocytes |
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Macrocytic anemia with Oval macrocytes and tear drop poikilotosis (high MCV)
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-commonly seen in megaloblastic anemias d/t vitamin B-12 or folate deficiency
-hypersegmentation or polymorphonuclear leukocytes is common feature |
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macrocytic anemia with round macrocytes
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-seen in conditions causing increase in reticulocytes or in liver disease
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Normocytic Normochromic Anemia: no poikilocytosis or polychromatophillic RBCs may indicate:
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-chronic infections
-neoplasms -chronic renal failure -endocrine dysfunction (hypethyroidism, hypopituitarism) |
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Normocytic Normochromic Anemia: poikilocytosis and occasional polychromatophillic macrocytes may indicate:
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-disturbance of erythrocyte maturation
-leukemias (esp p drug therapy) -myelofibrosis -carcinoma invading the bone marrow |
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Normocytic Normochromic Anemia: numerous polychromatophillic macrocytes may indicate:
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-hemolysis
-acute blood loss |
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In general, normocytic normochromic anemias typically indicate
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chronic disease or bleeding
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Microcytic hypochromic anemia with lack of reticulocytes may indicate:
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-compensated blood loss
-lack of response to therapy |
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Microcytic hypochromic anemia with increased reticulocytes may indicate:
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-bone marrow hyperplasia
-response to blood loss -response to therapy |
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Msot common cause of microcytic anemia is...
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iron deficiency
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Iron deficient can be ruled out if it deosn't meet the following criteria:
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-low serum iron
-high iron binding capacity -low ferritin |
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If iron deificiency is ruled out, consider..
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-thalassemia
-hemoglobinopathy (eg sickle cell) |
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If thalassemia and hemoglobinopathy are ruled out, consider..
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-anemia of iron overload
-sideroblastic anemia |
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Amount of iron an normal adult body contains:
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3.0-4.0 g of iron
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Relative levels of iron in a normal adult body:
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-hemoglobin: 66%
-tissure iron: 33% -myoglobin and cytochromes: <1% -plasma transferrin <0.1% |
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Normal plasma iron
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100-125 ug/ml
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Normal iron binding capacity
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300-400 ug/ml
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Normal saturation for circulating transferrin
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1/3 saturated
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RBCs in bone marrow can extract iron from....
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plasma
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Percentage of cardiac output received by erythroid marrow
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5% of cariac output
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Precentage of available iron extracted by erythroid marrow
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85% of available iron (so it is very efficeint at picking up iron)
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Iron deficiency definition
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total body iron is less than normal
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Sequential stages of Iron deficiency
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1. iron depletion
2. iron deficiency without anemia 3. overt iron deficiency |
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Iron depletion
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-normal serum iron and iron binding capacity
-low bone marrow iron stores |
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Iron deficiency without anemia
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-low serum iron and low iron binding capacity
-low bone marrow irons stores -normal hemoglobin and hematrocrit |
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Overt Iron deficiency
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-low serum iron and binding capacity
-absent bone marrow iron stores -low hemoglobin and hematocrit -microcytosis and hypochromia |
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Amount of time needed to manifest anemia
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2-4 months
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Iron Deficiency Anemia: prevalence
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-10-30% world population
-greater in woman, children, poor |
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Causes of Iron Deficiency Anemia in infants and childen
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-milk anemia (prolonged breast feeding bc breast milk has low iron)
-rapid periods of growth (iron cannot meet increased needs) -hookworm infections (parasites in intestines, chronic low grade bleeding in stool) |
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Causes of Iron deficiency anemia in adults:
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-loss of blood (menstruation, pregnancy, etc)
-VERY RARELY DUE TO INADEQUATE INTAKE |
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Iron lost during menstruation:
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0.7 mg/day
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Iron lost during pregnancy in formation of placenta/fetus
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4 mg/day
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Iron lost during hemorrhage of devlivery
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330 mg
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Iron deficiency in adult males may inducate:
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-colon cancer
-bladder cancer |
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Iron Deficiency Anemia: Sx
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-lassitude
-weakness -easy fatiguability -atrophic changes in tongue/corner of mouth -atrophy of gastric mucosa (histamine-fast achlorydia) -flattening/concavity of nails (spoon nails) |
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Lab results for iron deficency: peripheral smear
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-microcytic/hypochromic
-target cells may be seen -poikocytosis -anisocytosis -low reticulocyte count -inc or norm platelets -proliferation of erythroid cells in bone marrow (myeloid/erythroid ratio approaches 1:1) |
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Administration of iron should result in...
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-immediate erythrocyte reponse
-gradual rise in hematocrit and hemoglobin -retuculocytes in 10-15% (normally 0.5-1.5%) -some normoblasts may be seen |
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presence of target cells in microcytic hypochromic anemia suggests..
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-thalassemia
-hemoglobin problem |
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Heme consist of..
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-4 pyrrole rings surrounding a ferrous iron
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Globin consists of..
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-4 polypeptide chains
-for any type of hemoglobin, there are 2 pairs of chains |
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Chains for normal adult hemoglobin (Hemoglobin A1):
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-2 alpha
-2 beta |
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Chains for Hemoglobin F (fetal hemoglobin)
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-2 alpha
-2 gamma <1% of normal adult hemoglobin |
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Chains for hemoglobin A2
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-2 alpha
-2 delta 2% of total adult hemoglobin |
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Thalassemia definition
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-group of disorders wherein one or more of the globin chains is diminished or absent
-may effect alpha or beta chains |
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Thalassemia: prevalance
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-most common in Mediterranean Basin and Orient
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Thalassemia is d/t..
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-defect in the genes leading to a decrease in the production of mRNA reponsible for the synthesis of specific polypeptide chains
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Heterozygous beta chain thalassemia
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-only involved 1 beta chain gene
-mild hypochromia and microsytosis occur |
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Homozygous beta chain thalassemia
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-Cooley's anemia
-involves both genes controlling beta chain -no hemoglobin A1 is produced -hemoglobin F and A2 are increased (these have no beta chains) |
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Heterozygous alpha thalassemia
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-homoglobin alpha chains are minimally compromised
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Homozygous alpha thalassemia
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-no alpha chains are made
-no hemoglobin A1, A2, F |
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Thalassemis: Dx
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-hx of mild anemia since childhood
-microcytic hyprochromic RBCs -target cells -normal iron -increase in hemoglobin A2 and F |
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Suspect Hemoglobinopathies when...
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-hypochromic microcytic
-normal iron -target cells present -normal hemoglobin A2 and F |
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Most common types on hemoglobinopathies:
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-hemoglobin S (sickle cell)
-hemoglobin C |
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Hemoglobin S
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-glutamic acid is replaced by valine on the beta-chain of hemoglobin
(in normal, healthy person, glutamic acid is found on single locus on beta chain) -2 mutant beta chains and 2 alpha chains form hemoglobin S, which polymerises under low oxygen conditions causing a distoration of RBC |
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Hemoglobin C
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-abnormal hemoglobin with substitution of lysine for glutamic acid on the beta chain
-reduced plasticity of etythrocytes |
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Homozygous for Sickle Cell
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-produce all hemoglobin S
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Heterzygous for Sickle Cell
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-produce some hemoglobin S and some regular hemoglobin
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Consider sideroblastic anemia if..
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-cells are hypochromic/microcytic
-normal iron -no thalassemia -no hemoglinopahthy |
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Sideroblastic anemia
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-bone marrow has increased iron stores and normoblasts have a ring of iron in cytoplasm surrounding the nucelus
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Causes of sideroblastic anemia
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-toxins
-vitamin deficiency -mineral deficiency -lymphoma |
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3 categories for normocytic normochromic anemia:
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1. anemias d/t bone marrow failure
2. hemolytic anemia 3. refractory anemias (myelodysplastic syndrome) |
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Causes of Normocytic normochromic anemia:
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-exposure to drugs or chemicals (benzene derivatives, chloramphenicol)
-exposure to radiation -infection -consistitutional factors -idiopathic causes |
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Examples of anemias due to bone marrow failure
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-pure red cell aplasia
-anemia of chronic renal failure -anemia of endocrine disorders |
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Pure red cell aplasia (anemia due to bone marrow failure)
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-acute
-chronic -acquired |
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Examples of anemia of endocrine disorders (anemia d/t bone marrow failure)
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-pituitary disease
-thyroid disease -adrenal disease -gonadal disease |
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Clincal Mainfestations of hemolytic anemias:
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-increased hemoglobin catabolsim/breakdown
-decreased plasma haptoglobin -hemoglobinemia (free hemoglobin in plasma) |
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Increased hemglobin catablism from hemolytic anemia lead to..
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-elevation of unconjugated bilirubin
-increase in urine and fecal urobilinogen |
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Hemoglobinurea in hemolytic anemia
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-occurs when hemoglobin in plasma exceeds 30 mg/dl
-at this concentration, the capacity of the proximal tubular cells to reabsorb free hemoglobin is exceeded so free, unbound hemoglobin is excreted in the urine (this is abnormal) |
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Methalbuminemia in hemolytic anemia
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-free hemoglobin is catablized into methemoglobin
-some is transfered into albumin |
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Congenital hemolytic jaundice is characterized by..
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-mild elevation of indirect bilirubin
-high-normal MCHC -increased urobilinogen (colourless product of bilirubin reduction; part is resorbed and the rest is excreted in feces; trace amounts can be detected in urine) -no bilirubin in urine -negative direct antiglobulin test -peripheral smear shows spheroctyes -increase osmotic fragility of RBCs -increase in reticuloctyes and erythroid hyperplasia |
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Congential hemolytic jaundice
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-"hereditary spherocytosis"
-defect in membrane -autosomal dominant |
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Congeintial hemolytic jaundice: Tx
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-splenectomy
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Other conditions associated with spherocyte include:
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-acquired immunohemolytic anemia
-thermal injury -hypophosphatemia -chemical poisons -certain septicemias |
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Osmotic fragility test will prove...
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spherocytosis
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Other anemias due to membrane defects:
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-hereditary elliptocytosis
-hereditary stomatocytosis -microangiopathic anemia -paroxysmal nocternal hemogobinurea |
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Hereditary Elliptocytosis
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-cigar shaped elliptical cells
-membrance defect unknown -mild anemia |
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hereditary stomatocytosis
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-"fish mouth" RBCs
-membrane defects caused by hyperpermeability to sodium -potassium is forced out -hemolysis is usually mild -no improvement following splenectomy -found inceidentally following consumption of large amts of ETOH |
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Microangiopathic Anemias
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-damaged RBC appear as fragments
-helmet cells -traingular pieces or other distorred images |
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Causes of microangiopathic anemias
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-DIC
-prosthetic heart valve replacements -long distance runners (march hemoglobinurea) -following extensive burns |
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Paroxysmal Nocternal Hemoglobinurea
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-acquired disorder wherein the RBC membrane is hypersensitive to complement
-cause is unknown, perisists for life with no cure -platelets and WBCs may be effected -pt presents c fatigue and low grade anemia -reticulocytes present -spherocytes do NOT occur -mild respiratoty acidosis with sleep -hemoglobinurea in a.m. |
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hemolytic anemias d/t extracorpuscular defects:
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-caused by antibodies destroying the integrity of the RBCs
-acquired disorders -positive direct antiglobin test (direct Coombs test) d/t warm or cold autoantibodies -hemolysis is secondary to sequestration of cells in liver |
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Hemolytic anemias (extracorp. defect) caused by warm antibodies
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-idiopathic acquired autoimmune hemlytic anemia
-secondary immunohemolytic anemia |
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Idiopathic acquired autoimmune hemolytic anemia
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-mild to severe
-positive DAT of unknown cause -pt shows splenomegaly, marked spherocytosis, reticulocytosis |
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Secondary immunohemolytic anemia
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-develops with other disorder like neoplasma, leukemia, lupus
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Hemolytic anemias with cold antibodies
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-in association with viral disorders (esp pneumonia and mononucleosis)
-in association with lymphoproliferative disease -idopathic cold agglutinin disease -mild to severe anemia |
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Paraxysmal Cold hemoglobinurea
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-associated with syphilis
-produced intravascular hemolysis due to exposure to cold -antibody is known as Donath-Landsteiner antibody |
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Reticulocytes
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-immature red blood cells
-develop in mature in bone marrow |
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Number of reticulocytes is a good indicator of...
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-red bone marrow activity
-can be used to monitor the progress of the treatment of anemia |
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Increased reticulocytes (reticulocytosis) may indicate..
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-hemolytic anemia
-sickle cell anemia |
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Decresed reticulocytes may indicate...
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-chemotherapy
-aplastic anemia -pernicious anemia -bone marrow malignancies -problems with erythropoitin production -other casues of poor RBC production |
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Megaloblastic anemia
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anemia resulting from deficiceny in vitamin B12 and folilc acid
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Magaloblastic anemia hematologic findings:
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-dec RBC
-dec hemoglobin -increased MCV -normal reticulocyte -platelet dec or norm -macrocytes are present (large RBC) -ovalocytes may be present (oval shaped RBCs) -anisocytosis -poikilocytosis -bone marrow shows megaloblastic hyperplasia |
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anisocytosis
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increased varitaion in RBC size
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poikilocytosis
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abnormally shaped RBC
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Pernicious anemia
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-autoimmune anemia
-antibodies are directed against intrinsic factor or parietal cells that make intrinsic factor (intrinsic factor is required fo vitamin B12 absorption) -macrocytic anemia with low vita,in B12 |
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Hemolytic anemia
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-anemia d/t hemolysis (the abnormal breakdown of RBC) either within the blood vessels or elsewhere in the body (extravascular)
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Where are RBC cleared out of circulation?
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spleen
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Hemolytic anemia hematologic findings:
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-spherocytes (RBCs smaller and rounder than normal)
-increased reticulocytes -inc bilirubin levels -dec haptoglobin |
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Bilirubin
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-yellow breakdown of normal heme catabolism
-responsible for th yellow color of bruises -formed when RBC die and their hemoglibin is broken down within the macrophages to heme and globins -can lead to juandice |
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Haptoglobin
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-a protein in the blood plasma the binds free hemoglobin released from erythrocytes
-once bound, the haptoglobin-hemoglobin complex is removed via the spleen -decreased with hemolytic anemia |
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Aplastic anemia
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-bone marrow does not produce enough, or any, new cells to replenish the blood cells
-low RBC, low WBC, loe platelets |
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Sideroblastic anemia
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-anemia d/t abnormal production of RBC
-caused by toxins (lead/zinc), drugs (thanol, isoniazid), nutritonal (copper or pyrodoxine deficiency) |
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Sideroblastic anemia hemotologic findings:
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-inc ferritin
-dec total iron binding capacity |
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Sickle Cell disease
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-RBC change shape upon deixygenation bc of polymerization of the abnormal sickle hemoglobin (Hgb S or Hb S)
-damaged RBC can casue RBC to become stuck in blood vessels and cause obstructions (infarction, ischemia) |
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Sickle cell hemotologic findings:
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-microcytic, hypochromic
-inc reticulocytes (reflecting new RBC replacing the rapidly destroyed older RBCs) -inc WBC and platelet (often) |
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Thalassemia
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-genetic defect results in synthesis of abnormal hemoglobin molecules
-as a result, blood cells are vulnerable to mechanical injury and early death |
