Evaluation of Erythrocytes: Anemia and Regeneration Flashcards Preview

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Flashcards in Evaluation of Erythrocytes: Anemia and Regeneration Deck (71)
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1

What important information from a history can help you diagnose the cause of an anemia?

prior drug administration exposure to toxic chemicals or plants family or herd occurrence recent transfusion or colostrum ingestion age at onset of anemia

2

Physical findings associated with anemia

pale MM weakness, loss of stamina, exercise intolerance tachycardia and tachypnea, esp. after exercise cardiac murmur secondary to increased blood turbulence shock if rapid severe hemorrhage occurs icterus, hemoglobinuria, hemorrhage, or fever - depending on dz present

3

Normal HCT with low TPP leads you to what DDX?

GI protein loss proteinuria liver dz

4

Normal HCT with high TPP leads you to what DDX?

increased globulin synthesis dehydration masked anemia

5

High HCT with low TPP leads you to what conclusion?

protein loss combined with relative or absolute erythrocytosis

6

High HCT + High TPP = ?

dehydration

7

Low HCT + low TPP =?

substantial ongoing or recent blood loss, overhydration

8

High HCT + normal TPP =

splenic contraction absolute erythrocytosis dehydration masked hypoproteinemia

9

low HCT + normal TPP =

increased erythrocyte destruction, decreased erythrocyte production, chronic hemorrhage

10

low HCT + high TPP =

anemia of inflammatory dz multiple myeloma lymphoproliferative dz

11

How do you classify an anemia as regenerative or non regenerative?

absolute reticulocyte count increased increased polychromasia on blood film marrow evaluation

12

What are the size and color classifications of anemia?

microcytic (MCV below reference), normocytic (MCV in reference), macrocytic (MCV above reference) hypochromic (MCHC below reference), normochromic (NO hyperchromic)

13

T/F hemodilution is a true anemia

F

14

T/F severity can rule in or out a specific cause of anemia

T - ie. severe anemia should not be attributed alone to anemia of inflammatory disease

15

What are the four pathophysiologic mechanisms of anemia?

blood loss or hemorrhage accelerated erythrocyte destruction (hemolysis) reduced/defective erythropoiesis hemodilution (not really an anemia)

16

Hemodilution "anemia"

expansion of vascular space - pregnancy, growth (plasma volume expansion, dilution from colostrum, destruction of fetal RBCs, decreased production of erythropoietin in first few months of life) overhydration splenic sequestration - splenomegaly, anesthesia, heparin treatment in horses

17

Which species is not ideal for a bone marrow evaluation?

Horses

18

What does regenerative anemia look like on blood films?

increased polychromasia increased anisocytosis metarubricytosis increased howell-jolly bodies basophilic stippling ONLY increased polychromasia is a valid indicator of regeneration - all else associated with but not indicator

19

Why would an acute hemorrhagic or hemolytic anemia initially appear non-regenerative?

because it takes bone marrow 3-5 days to respond to an anemia

20

What are features that may be seen in blood smears as part of the regenerative response but are not specific for regeneration?

anisocytosis increased numbers of nucleated RBCs basophilic stippling (aggregates of ribosomes and polyribosomes, especially seen in ruminants but can also be seen in dogs and cats) increased numbers of RBC containing Howell-Jolly bodies (remnants of the nucleus)

21

How does MCV change in a regenerative response to anemia?

within reference range early (takes 3-4 days for bone marrow to respond), then highest in hemolytic anemia (spherocytes from phagocytosis by macrophages and polychromatophils from regeneration) ***may be low with chronic blood loss

22

What does the MCHC look like in a regenerative anemia?

within reference range early low with a high percentage of reticulocytes, especially "stress reticulocytes"=released early from BM

23

Clinical signs of hemolytic anemia

depends on severity and speed of onset icterus may be present if rapid RBC destruction red plasma hemoglobinuria (if intravascular hemolysis present)

24

Laboratory findings of hemolytic anemia

reticulocyte counts higher than external hemorrhage plasma protein concentration normal or increased leukocytosis with neutrophilia and monocytosis bilirubinemia, hemoglobinemia, +/-hemoglobinuria abnormal erythrocyte morphology (ie. heinz bodies, poikilocytes, spherocytes, parasites)

25

Extravascular hemolysis often occurs in which organs?

spleen, liver, bone marrow

26

Which is acute or chronic - extravascular hemolysis or intravascular hemolysis?

Extravascular - can be either

intravascular - often rapid - per acute or acute

27

DIC occurs as a result of ________ (extravascular/intravascular) hemolysis.

both can cause DIC

28

Which has a worse prognosis intravascular or extravascular hemolysis?

intravascular - abnormal location for RBC destruction, usually rapid, not an isolated environment = fragments are a risk for DIC and anaphylactic shock

29

What is the pathological mechanism that causes hemoglobinuria?

lysed RBCs free Hgb into bloodstream - transport protein binds and it is taken to liver for metabolism and recycling. transport capacity is overwhelmed if destruction is rapid and/or severe enough - left over circulating Hgb is excreted in the urine

30

Where does bilirubin back up to first (if RBC destruction too rapid/severe to be excreted via normal mechanisms)?

backs up to urine and feces first = bilirubinuria then backs up in plasma = bilirubinemia then backs up to mucocutaneous tissues = icterus