Basic Blood Flashcards
What are the 3 parts of a CBC?
PCV/TP and Plasma Color
Analyzer
Blood smear
PCV measures the % of what?
Erythrocytes
What RBC changes might influence the PCV?
Anemia
Dehydration
Iron deficiency - smaller RBCs
When evaluating the plasma color in a PCV, what does a pink or red tinged plasma indicate?
Hemolysis
*hemoglobin
What does yellow plasma indicate in small animals?
Icterus
*bilirubin
What does yellow plasma indicate in large animals?
NOTHING
Large animals usually have yellow plasma due to carotene pigments in the diet
Why is protein concentration an estimate?
It assumes other solutes in the serum are present in normal concentrations.
What solutes will artificially increase protein concentration values?
CHUGL Cholesterol Hemoglobin Urea Glucose Lipemia
Which scale on the refractometer is used to measure TPP?
The 1-15 scale
What can we use to evaluate morphological abnormalities of cells in the blood, and determine the differential cell count?
Blood smear/film
Blood films are stained with:
Modified Wright Stains in-clinic “Diff-Quick”
At what region of the blood film should you look for platelet clumps and organisms such as microfilaria?
Feathered edge
What region of the blood film is used to estimate the RBC and WBC count and with what power lens?
Monolayer with 10x lens
What can be determined by viewing the monolayer of the blood film with the oil lens?
Evaluation of RBCs, WBCs, and platelets, and differential cell counts
T/F: Blood cells can be evaluated in either the monolayer or in the body of the blood film.
FALSE
Cells should not be evaluated in the body of the film. RBCs are often in rouleaux and WBCs are condensed.
T/F: Total Nucleated Cell Concentration is the best way to interpret percentages of each WBC in the blood.
FALSE
The analyzer only detects the concentration of nucleated cells present, including nucleated RBCs. TNCC is mainly used to calculate the concentration of specific leukocytes after a differential cell count is performed.
Differential Cell Count measures percentages of what cell types?
BLEMS
Bands Lymphs Eos Monos Segs
Multiplying the percentage of each individual leukocyte type by the total nucleated cell count will give what value?
Absolute Cell Count
Which 2 analyses are needed to determine the absolute cell count?
Differential Cell Count (percent of a certain cell) x Total Nucleated Cell Count
200 leukocytes are counted.
120 are neutrophils, 40 are eosinophils, 20 are monocytes, and 20 are lymphocytes.
TNCC is 10,000 cells/uL
Calculate the Absolute Cell Count for each type of cell.
Neut: 120/200 = 60% 0.60 x 10000 = 6,000 cells
Eos: 40/200 = 20% 0.20 x 10000 = 2,000 cells
Mono/Lymph: 20/200 = 10% 0.10 x 10000 = 1000 cells
RBC, HGB, and HCT measure what?
Number of erythrocytes
MCV, RDW, and RBC histogram measure what?
Size of erythrocytes
What values give the amount of hemoglobin in a sample?
MCH and MCHC
Erythrocyte concentration (RBC) is the number of RBCs in what fixed volumes of blood?
x10^6/uL
x10^9/L
HGB is measured by spectrophotometry and gives the grams of _______ per unit volume. (g/dL)
Hemoglobin
What is the formula for calculating the HCT?
RBC x MCV / 10
HCT and PCV should be within ___ of each other.
3%
The average volume of RBC in a sample is the ____, and is measured with erythrocyte concentration.
Mean Cell Volume (MCV)
A wider RBC curve, or higher Red Cell Distribution Width (RDW), indicates more RBC size variation, also known as ________.
Anisocytosis
What does the discriminator line on an erythrocyte histogram denote?
Separation between platelets and smallest RBCs that will start the curve.
The mean cell volume can be found at which point on the graph?
Peak
When looking at an erythrocyte histogram, a shift to the left indicates what about the size of the RBCs?
What can be a potential cause for this?
Decreased MCV (microcytosis)
Can be caused by iron deficiency anemia
When looking at an erythrocyte histogram, a shift to the right indicates what about the erythrocytes?
What can be a potential cause for this?
Increased MCV (macrocytosis)
Can be caused by regenerative response (immature RBCs are larger)
What is the difference between MCH and MCHC?
MCH is just a calculation of the average amount of hemoglobin per RBC
MCHC is a calculation of the average density of hemoglobin per RBC
What is the formula to calculate MCHC?
HGB / HCT x 100
T/F: The term hypochromia refers to a low MCHC, indicating lower than normal hemoglobin concentration per RBC.
TRUE
What can cause hypochromia?
Regenerative anemia (immature RBCs won’t have full amount of Hg)
SEVERE iron deficiency
For regenerative anemia to produce a low MCHC, what percent of the RBCs have to be immature?
over 20%
What is the difference between hypochromia and hypochromasia?
Hypochromia is a calculated value indicating low HGB.
Hypochromasia is a descriptive term for blood films to describe RBCs that look to have decreased HGB concentration. These cells will have a trace amount of hemoglobin around their edges. Hypochromasia indicates severe iron deficiency and doesn’t always show up as decreased HGB on MCHC.
T/F: The term hyperchromia refers to a higher than normal MCHC value and indicates a serious disease process.
FALSE: high MCHC is an artifact.
What are some causes of a high MCHC?
- (HGB / HCT x 100)
Erroneously high HGB: Intravascular hemolysis
Increased turbidity: Lipemia, Heinz bodies
Falsely decreased HCT: Agglutination
You stain a blood film with New Methylene Blue and see some cells that are lavender, and a bit larger than all the other RBCs. What are these cells?
Reticulocytes - immature RBCs
Polychromatophils on blood film because they take up some of the blue stain.
What type of reticulocytes are included in the retic count for cats and are polychromatophilic on blood films?
Aggregate: contain organelles and are notably larger
Which type of reticulocyte is a better indicator of an acute response in cats?
Aggregate because they will turn into punctate retics within 12 hours.
Punctate retics take about 12 days to mature into RBCs, so they are not good indicators of acute response.
A blood film on a dog shows 60,000 retics/uL. Does this indicate a regenerative response?
No
What is the upper limit of normal retics/uL for a cat?
40,000
What is the upper limit of retics/uL in a normal blood sample from a cow?
0
Any reticulocytes in a cow sample indicate a regenerative response
What is the upper limit of retics/uL in a normal blood sample from a horse?
Horses don’t release reticulocytes into the blood. To confirm a regenerative response, a bone marrow tap is necessary.
What do the following reticulocyte values indicate:
0-10,000/uL
10,000-60,000/uL
60,000-200,000/uL
>200,000/uL
0-10,000 = non regenerative anemia
10,000-60,000 = poorly regenerative anemia
60,000-200,000 = mild/moderate regeneration
> 200,000 = maximal regeneration
