click below
click below
Normal Size Small Size show me how
Hemolytic Anemia
Clinical Medicine II
Question | Answer |
---|---|
What is hemolytic anemia | increased RBC destruction (5%) all anemia worldwide |
What happens w/ hemolytic anemia | low RBCs, Hgb released from RBC |
What happens w/ ↑ Hgb release in blood | ↑breakdown of it: jaundice, ↑indirect bilirubin, gallstones, ↓haptoglobin |
What does ↑ destruction cause | ↑ RBC production: ↑reticulocytes, skeletal changes d/t over-active bone marrow |
What does a reticulocyte >2.5% suggestive of | hemolytic anemia, also higher in acute blood loss w/ erythroid compensation, also, adding a deficient molecule show up to 20% increase |
How do we screen/monitor Hemolytic anemia | monitor haptoglobin and retic count |
Why does haptoglobin decrease with HA | ↑ release of Hb d/t destruction of RBCs, Hp binds to the free Hb ↓ the free Hp |
Retic count for deficiency anemia | .5-2.0 (>1.5 would be d/t compensation but not significantly high) |
Signs of extravascular hemolysis | splenic hypertrophy/meagly, iron overload |
Signs for intravascular hemolysis | ↑free Hgb in plasma, ↑hemosiderin, ↑ met Hgb, no haptoglobin, hemoglobinuria (dark urine) ↑LDH |
Common triad of hemolytic anemia | normocytic or microcytic anemia, ↑ retic count >2,5, hyperbillirubinemia |
Defect of Structural protein of RBC membrane (Na/K ATPase) | hereditary spherocytosis, forms spherocytes ↑osmatic fragility, cells can’t pass thru spleen: hemolysis |
Presentation of hereditary spherocytosis | ↑MCH and MCHC, jaundice, splenomegaly, gallstones, (hyperchromic) |
Tx hereditary spherocytosis | control anemia, splenectomy, pneumococcal vaccine |
Defect in structural protein forming weak elliptical cells | hereditary elliptocytosis (less severe) d/t able to pass through spleen |
How does RBC get ATP | glycolysis |
Where is glucose-6-phosphate dehydrogenase deficiency seen | Africa, mediterranean, middle east, south east asia |
What is G6PD protective of | malaria |
Patho G6pd | can’t convert to 6phosphate gluconate, so ↓ NADPH, ↓ glutathione, no protection against oxidation, RBC’s destroyed |
induce G6PD def | antimalarials, nitrofurantoin, NSAIDS, quinidine, quinine, sulfonamides, aspirin and infx, fava beans |
Acute sxs of G6PD def | malaise, weakness, abd/back pain, ↑bilirubin, jaundice, dark urine/hemoglobinuria |
Diagnosis of G6PD | normochromic/cytic anemia, During attack blood smear shows bite cells, ↑free Hb, so ↓Hp, ↑reticulocytes, ↑LDH, ↑billirubin, G6PD screening, DNA analysis |
Sxs of G6PD | malaise, weakness, abd/back pain, ↑bilirubin, jaundice, |
Complications of G6PD | Acute: renal railure, aplastic crisis Chronic: bilirubin gallstones, splenomeagaly |
Problem with PKD | loses 2 ATP production |
Metabolic defect of PKD | no PK to conversion to pyruvate (PEP) which loss of ATP→↓ATP causes RBC rigidity: hemolysis: removed by spleen |
Presentation and Dx of PKD | neonatal jaundice, ↑ reticulocytes, splenomegaly (broad anemia signs), dx: enzyme and DNA analysis |
Tx of PKD | supportive, ↑ folic acid, avoid transfusions if not severe, iron chelation? Splenectomy? |
Where is thalassemia commonly seen | Mediterranean |
Genetic varience of alpha-thalassemia | 1-4 gene deletion (seen in Asians) |
Signs for 2-3 gene mutation | microcytic anemia, ↑ reticulocyte, splenomegaly, |
1 gene mutation is what | asymptomatic and a carrier trait |
Pathology of thalassemia | imbalance f a and b chain production: ineffective erythropoiesis, hemolysis of mature RBCs |
What is often mistaken for iron def | thalassemia minor, heterozygous, mild anemia, nl life-expectancy |
How does b-thalassemia major usually present | 1st 2nd yr, failure to thrive |
Tx b-thalassemia | severe anemia needs transfusions q4-6wks |
Dx of thalassemia for mild to severe | ↓Hgb, HCT, MCV, MCH and ↑ reticulocytes Hgb eectophoresis |
Growth findings of thalassemia | growth retardation, bone deformities d/t ↑bone marrow production, no room, splenomegaly |
Fxns of transfusions for tx thalassemia | ↑nl Hgb corrects anemia, suppressing ineffective erythropoiesis |
Dx b/w iron def and thallasemia | thalassemia is ↑ reticulocytes |
Issue w/ concurrent transfusions | iron overload, will need to tx eventually |
What causes fatality of thalassemia | iron overload→CHF, infection, liver failure |
Pathotphys of sickle cell anemia | adenine is replaced by thymine (single substitution): glutamic acid replaced by valine, Hgb loses –charge |
When hgb is – what happens | O2 can’t bind, causes hgb to polymerize into rigid bundles: sicke shaped |
Problem with sickle cell shape | ↓ O2 carrying, impair blood flow →tissue ischemia cause death |
Genetic inheritance of sickle cell , protective against what | autosomal recessive, malaria with both |
Complications and symptoms of sickle cell | fatigue, anemia, recurrent painful vaso-occlusive crisis could result in acute/chronic multisystem organ failure |
What are sickle cell crisis precipitated by | infection, dehydration, cold, acidosis, hypoxia, |
Set test for dx sickle cell | hemoglobin electrophoresis, blood smears, but will have these vaso-occlusive episodes |
Tx sickle cell | hydroxyruria, transfusions, folic acid supplements, iron chelation, prompt tx of infxs |
Why do we give hydroxyuria | ↑Hgb fetal, (more nl and resistant to sickling) and also ↓ WBC and reticulocytes |
Why do we give transfusions | proportion of Hgb S and sickling |
What do we do for a sickle cell crisis | IV fluids, O2, rest, pain med, alagesics (narcs/nsaids) transfuse to maintain adequate Hgb concentration, organ management, splencecomy? |
Most life threatening hemolytic anemia | B-thalassemia and sickle cell |
Purpose of transfusions | “normalize” Hgb, O2 delievery, and suppress ineffective erythropoiesis |
Attracting macrophages and neutrophils | chemotaxis |
Enhancing phagocytosis of antignes | opsonization |
Rupturing of membranes of foreign cless - | cell lysis |
AG-bearing agents | clumping |
Direct antiglobulin | AG added to pt’s RBCs detects IgG and compliments bound to RBC membrane Agglutination-+test |
Indirect AG test | detects autoantibodies and alloantibodies induced by transfustions ( mixing blood) |