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27 Cards in this Set
- Front
- Back
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Clinical manifestation of Anemia of any etiology include what 2 things?
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1. Direct effects of decreased oxygen delivery
2. Compensatory mechanisms to prevent tissue anoxia (inc pulse, angina, exertional dyspnea, pallor) |
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Physiologic manifestations of Anemia of any etiology include?
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-decreased affin of Hgb (right shift)
-inc CO/angina -inc resp rate -inc prod of 2,3 DPG (right shift) -shunting of blood from periph (vasoconstriction and pallor) -inc RBC prod (reticulocyte count) |
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Intravascular Hemolytic Anemia
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-severe injury/trauma
-Complement and immune regulated -will have a positive DAT test |
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Extravascular Hemolytic Anemia
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-mild/moderate injury, spherocytes may be present
a. dec SA to volume ratio b. Inc internal viscosity c. Hypersplenism |
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General laboratory features of hemolytic anemia
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-low Hgb/Hct
-high reticulocyte count -increased lactase DH (when RBCs lyse their contents spill out) -decreased hepatoglobin -increased bilirubin |
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Specific diagnostic tests to determine the cause of hemolytic anemia include?
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-shistos/poikliocytes, spherocytes, ovalocytes, sickle cells
-Hgb electrophoresis -Hgbinemia/Hgburia -osmotic fragility -DAT/IAT/eluates (determined whether there is immune mediated hemolysis) -G6PDH level |
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Congenital Hemolytic Anemia
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-abnormal Hgb (qualitative)
-abnormal Hgb (quantitative) -enzyme defects -membrane defects |
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Acquired hemolytic anemia
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-immune mediated (autoimmune hemolytic anemia)
-mechanical |
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Qualitative Abnormal Hgb
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-plenty produced jut not good quality
a. sickle cell anemia b. Hemoglobin C c. unstable Hgb |
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Quantitative Abnormal Hgb
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-less is produced
a. alpha thalasssemia b. beta thalassemia |
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HgbA, HgbS, HgbF
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HgbA = normal adult Hgb
HgbS = abnormal sickle cell Hgb HgbF = fetal Hgb -if someone is A/S then they have sickle cell trait not disease or s/s |
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***People who have sickle cell disease which have HgbF dominance do not have s/s of sickle cell anemia, why?
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-bc HgbF is not mutated, this Hgb can deliver O2 efficiently to tissues, preventing tissue anoxia and sickle cell signs and symptoms
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Etiology of abnormal Hgbs
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-amino acid substitutions lead to change in charge which leads to change in 3D configuration
-changes shape of cell and thus fxn of Hgb--> less O2 delivered to tissues |
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Severity of Clinical disease - Asymptomatic to Death
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1. amount of Hgb A/F/S
2. presence of coexistent Hgb abnormalities 3. Degree of de-oxy (relate to the severity of symptoms displayed by pt, includes infx, vasc statis, cynosis, drugs, temp, acidosis) |
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Clinical disease:
Well being - intermittent crisis |
-most pts have periods of intermittent crisis:
-ischemia - pain infarction -aplastic -hemolytic -acute chest syndrome |
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Progressive s/s of sickle cell anemia
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-growth retardation
-bony abnormalities -decrease in spleen size (many pts undergo autosplenectomy) -ocular -CNS -leg ulcers -OB/GYN priapism |
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Tx of Sickle Cell Anemia
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1. Anti-sickling agents - hydroxyurea
2. Supportive care 3. RBC exchange (in case of medical emergencies, *Ag matching RBCs*) 4. BM/stem cell transplant |
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Future of Sickle Cell anemia tx
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1. BM/Stem cell tx
2. Gene therapy -in an experiment 10 of 12 ppl were "cured". Still have HgbS but there is an inc in Hgb A so therefore there are no clinical symptoms |
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Beta Thalassemia Minor
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-"Thal trait"
-one gene is abnormal -overall normal Hgb |
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Beta Thalassemia Intermedia
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-2 genes abnormal but some Bega globin produced
-mild to mod anemai |
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Beta Thalassemia Major
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-2 genes abnormal and little beta globin produced
-severe anmeia -high Hgb F 1-5% Hgb A |
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Alpha Thalassemia
Silent Carrier |
-one missing gene
-normal Hgb -no disease |
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Alpha Thalassemia trait/minor
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-2 missing genes
-mild anemia |
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Hemoglobin H disease
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-3 missing genes
-moderate to severe anemia |
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Alpha Thalassemia Major
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-aka Hydrops Fetalis
-all 4 genes missing -death before or shortly after birth |
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Tx of Thalessemias
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-none
-except transfusion and iron chelation -requires genetic counseling -early death from iron overload |
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Special considerations w/ Thalessemias
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-combination and subgroups of alpha and beta thal in one individual is common
-combination w/ SS disease is common |
