Ch 31

  1. deficiency in the #of RBCs, Hgb, and/or volume of packed RBCs (Hct)
    • Anemia:
    • causes: blood loss (GI/ulcer bleeds, colon cancer, liver disease, trauma, ruptured aneurysm), impaired production in erythrocytes (bc of deficient nutrients-iron, cobalamin, folic acid; decreased erythropoietin, or iron availability), increased destruction of erythrocytes (HgbS, meds: methyldopa "Aldomet", blood incompatability, trauma)

    important labs: CBC, reticulocyte count, peripheral blood smear
  2. Clinical manifestations of anemia
    • are caused bc of tissue hypoxia
    • Decrease in Hgb (normal: 12-17); decreased Hct (normal: 35-50%); decreased RBCs (normal: 4-6);
    • palpitations, dyspnea, fatigue, worse when these are worse and occur even at rest, pallor(decreasedHgb and blood flow to skin), jaundice (hemolysis of RBCs), pruritis (increased serum and skin bile salts), increased HR and stroke volume to maintain cardiac output an dprovide adequate O2
  3. Interventions for anemia
    Acute: blood/product transfusion, drug therapy (erythropoietin, vit supplements), volume replacement, O2 therapy
  4. Aging and anemia
    • decline in Hgb (more in men) bc of decreased androgen production
    • cobalamin (vit B12) deficiency bc of malabsorption or decreased dietary intake
    • S&S- pallor, confusion, ataxia, fatigue, worsening angina, HF
  5. Anemia caused by decreased erythrocyte production (3 reasons)
    • alterations of erythropoiesis:
    • -decreased Hgb synthesis - leads to iron defiency anemia, thalassemia, sideroblastic anemia
    • -DNA deffect in synthesis of RBCs - leads to cobalamin or folic acid deficiency
    • -diminished availability or erythrocyte precursors - lead to aplastic anemia, anemia of chronic disease
  6. Iron deficiency anemia
    • causes decreased erythrocyte production
    • most common chronic hematologic disorders
    • *reduced heme synthesis is the problem
    • very young, on poor diet, reproductive women, older adults
    • develops from - inadequate intake, malabsorption, blood loss, or hemolysis
    • iron absorbed in duodenum
    • concerns - alcoholism, GI surgery, malapsorption - i.e. Crohns, black stools from GI bleed, CKD- dialysis  tx causes blood loss
    • manifestations: *pallor, *glossitis, *cheilitis, headache, paresthesias, burning tongue
    • Tests: stool guaiac test, endoscopy, colonoscopy, bone marrow biopsy
    • Good source of Iron: liver, egg, dried fruit, legumes, dark green leafy vegetables
    • Tx: teach iron food sources, packed RBC transfusion for acute blood loss,
    • admin iron supplement: don't use enteric coated or sustained release, acidic environment increases absorption (give 1hr before meals, take with vit C or OJ), liquid form can stain- use straw, causes: heartburn, constipation/diarrhea, black stool, continue to take for 2-3mths after Hgb returns to normal
  7. Thalassemia
    • causes decreased erythrocyte production
    • life threatening group of dieases with autosomal recessive genetic basis involving inadequate Hgb production
    • *reduced globulin production is the problem
    • manifestations: causes physical and mental growth problems, symptoms develop by age 2, splenomegaly, hepatomegaly, jaundice is prominant (d/t hemolysis), increased RBC production to make up for deficient O2 function- eventually causing bone marrow hyperplasia and hypercoagulable state, HepC- d/t transfusions, cardiac complications, pulmonary disease, HTN
    • Tx: no drug or diet therapies are effective in treating thalassemia, symptoms are managed by blood transfusions (chronic transfusions can cause iron overloading- meds to bind iron and prevent this: deferasirox, desferoxamine), splenectomy (bc RBCs are sequestered in enlarged spleen, iron chelation therapy - live longer
  8. Megaloblastic anemias - caused by  impaired DNA synthesis (causes defective RBC maturation) and characterized by large RBCs (called megaloblasts- more fragile) 
    result from colbalamin (vit B12) or Folic acid deficiencies
  9. Cobalamin (vit B12) Deficiency
    • most common cause- pernicious anemia (where gastric mucosa isn't secreting intrinsic factor (IF) bc antibodies being directed against gastric parietal  cells and/or IF itself (IF is needed for cobalamin absorption)
    • other causes- gastrectomy, gastric bypass, chronic gastritis, nutritional, alcoholism, small bowel ressection of ileum (where vit B12 absorbed), crohns, celiac disease, long term use of H2-histamine receptor blockers and PPIs (decreased acid prevents absorption), and *strict vegetarians
    • common after age 60, increases rick for gastric cancer
    • manifestations: general; sore red beefy  shiny tongue, N/V, anorexia, abd. pain, weakness, paresthesias in hands and feet, confusion, dementia
    • Tests: RBC's are large and abn. shape, upper GI endoscopy, schilling test - measures cobalamin excreted in urine
    • Tx: increasing vit B12 in diet doesn't help, tx of choice: parenteral or nasal  admin of cobalamin for life (without - will die in 1-3yrs
  10. Folic acid deficiency
Card Set
Ch 31
Hematologic Problems