Clin Path 1: RBC Mass and Indices Flashcards
Define anemia
a reduction in the RBC, Hgb, and PCV (or HCT)
What values do you focus on when evaluating a CBC for RBC mass? Which do you believe?
PCV or HCT - always believe PCV
Define erythrocytosis
increased PCV or HCT (often with concurrent increases in RBC count and Hgb)
Define polycythemia
erythrocytosis
Define macrocytosis
RBC larger than normal
What is the #1 cause of macrocytosis?
reticulocytosis
Define microcytosis
RBC smaller than normal
What is the #1 reason for microcytosis?
iron deficiency
Define hyperchromasia
mean corpuscular hemoglobin concentration (MCHC) increased/ small RBC
What does it mean if you see hyperchromasia on bloodwork results
artifact - no physiological state resulting in this
Define hypochromasia
MCHC decreased/large RBC
What is the #1 reason for hypochromasia? #2?
reticulocytosis
iron deficiency
What does reticulocytosis indicate?
regenerative anemia if high enough in number
Define metarubricytosis
presence of nRBCs in peripheral blood
What is appropriate metarubricytosis?
erythroid hyperplasia - occurs concurrently with reticulocytosis associated with regenerative anemia
What is inappropriate metarubricytosis?
if nRBCs are seen in the absence of reticulocytosis
What is considered a mild PCV threshold for dogs and cats?
dogs > or = 33%
cats > or = 26%
What is considered a moderate PCV for dogs and cats?
dogs > or = 24%
cats > or = 23%
What is considered a marked PCV for dogs and cats?
dogs < or = 23%
cats < or = 23%
What parameter is best for classifying the regenerative status of anemia for dogs, cats, and horses?
dog > 80,000 uL
cat > 60, 000 uL
horse …. no
What is the pathogenesis of anemia?
tissue hypoxia
What are the clinical signs of anemia as far as “symptoms” go?
lethargy, exercise intolerance
What would a veterinarian find during a physical exam of an anemia patient?
pale mucous membrane, hemodynamic compensation, hepatomegaly, splenomegaly
What are possible causes of macrocytosis?
reticulocytosis (regeneration),
felv,
folate/cobalamin deficiency
What are possible causes of microcytosis?
iron deficiency
liver disease
What are possible causes of hyperchromasia?
artifact
What are possible causes of hypochromasia?
reticulocytosis
iron deficiency
liver disease
What are possible causes of reticulocytosis?
blood loss
hemolysis
hypoxia
What are causes of appropriate metarubricytosis?
erythroid hyperplasia
What are causes of inappropriate metarubricytosis?
bone marrow disease (leukemia, fracture, hypoxia) or splenic disease
If hypoplasia (atrophy) is the cause of anemia, is it nonregenerative or regenerative?
Non-regenerative
If hemorrhage or hemolysis is the cause of anemia is it nonregenerative or regenerative
regenerative
What does pre-regenerative mean?
takes 2-3 days to see response following cause of anemia
If it is > 2-3 days and there is reticulocytosis what does that mean?
regenerative anemia likely caused by hemorrhage or hemolysis
If it is > 2-3 days and there is no reticulocytosis what does that mean?
non-regenerative anemia caused by hypoplasia
What are the components of Red Cell Mass and what does it tell you?
RBC
Hemoglobin
Hematocrit
Packed cell volume
Tells you how many red cells in the blood
What are the components of RBC indicies and what does it tell you?
MCV
MCH
MCHC
Tells you about the RBC such as size or color
What is plasma and what does Plasma Appearance tell you?
plasma is free fluid component after spinning in centrifuge and the RBC fall to the bottom as the PCV
Plasma appearance can tell you about what is going on within the body
What does it mean if the plasma is yellow?
bilirubin in blood - bilirubemia
What does it mean if the plasma is white?
lipidemia
What does it mean if the plasma is red
RBC are lysed - hemoglobenemia
What should the value of Hct % be
equal to PCV
What should the value of the Hgb conc be?
1/3 of PCV
What does it mean if PCV is decreased
anemia
How does erythrocytosis or polycyhtemia influence PCV?
increases PCV since free water has decreased due to dehydration
What are polychromatophils vs reticulocytes
polychromatophils are bigger, bluer, and have less Hgb than reticulocytes and are only seen on stain
What are the uses of reticulocytes?
Bone marrow health
RBC regeneration
How do feline reticulocytes differ from other species
Aggregate - young, immature, recently released
Punctate - aggregate cells mature into punctate and stick around for 2 weeks
What does reticulocyte number indicate?
if bone marrow is responding to anemia
What are the uses of nRBCs
Bone marrow health
splenic health
If an animal has macrocytic hypochromic lab values what does this indicate?
reticulocytes increased and regenerative anemia
If an animal has microcytic hypochromic lab values what does this indicate?
iron deficiency
What is Mean Corpuscle Value (MCV)?
Measures size of RBC
Micro or macrocytosis
What is Mean Corpuscle Hemoglobin Concentration (MCHC)?
Average conc. of hemoglobin in blood
Hypo or hyperchromasia
How would sample storage affect PCV?
increase
How would hemolysis affect PCV?
decrease
What is the equation for HCT on a blood sampling machine?
(MCV * RBC) /10
How would RBC agglutination affect HCT?
unpredictable
How would hemolysis affect HCT?
decrease
How would sample storage affect RBC?
decrease
How would RBC agglutination affect RBC?
decrease
What are 3 ways that Hgb (increased MCHC) would be affected?
Lipemia
Hemolysis
Heinz Bodies
