Exam 1: Week 1 Flashcards
Clinical Pathologist
A veterinary clinical pathologist is a veterinarian who studies diseases in animals, examines blood, tissues, and fluids, and is responsible for the accuracy of laboratory tests
Clinical pathology is…
what is hematology, biochem, and cytology
diagnostics for live animals
* hematology: look into blood
* biochemistry: look into organs
* Cytology: needle in mass or fluid from body cavity
Hemoglobin
Oxygen caryng molecule in red blood cells
reticulocytes
baby red blood cells
A reticulocyte is a young/immature erythrocyte which still contains ribosomes & mitochondria in the cytoplasm
diff types of stain, Wright=purp/blue other shows residual organelles
reference intervals
healthy and unhealthy and sometimes the numbers overlap, so take lab results with a grain of salt. somtimes animals fall in “tails” - look at the animal.
What questions does a CBC answer?
complete blood cell count
* is there anemia?
* is there inflammation?
* is there leukemia?
* platelets okay? Is there enough?
three tests that provide a good screening of the systemic health of a patient
- serum biochemical panel (tells you about organs)
- urine analysis (do not call kidney failure until you do this)
- CBC
Select the appropriate types of collection tubes that are used for CBC, biochemical profile, coagulation profile, and glucose when serum can’t be separated from clot.
CBC: purple
biochemical profile: red
coagulation profile: blue
glucose: gray
Recognize errors that can be introduced when incorrect tubes, collection methods, and storage methods are used.
incorrect tube errors: coagulation when you don’t want.
collection methods: not putting it up or taking out the serum in time, cells can bloat. sampling error can cause coagulaiton and an incorrect (low) platelet count.
storage methods: if frozen, sample can expand and ruin information. not putting in enough sample in a tube with EDTA can cause erythrocytes to shrink.
Describe the importance of, and method for, performing reticulocyte enumeration
importance? helps us to assess whether or not an anemia is regenerative.
method? add EDTA to blood stain, mix tube and incubate for 10 minutes, use drop to make blood film, let dry, examine.
to read? count 1000 red blood cells, categorize cells as either reticulocytes or normal cells, derive the percentage of reticulocytes, calculate absolute reticulocyte count.
RBC/ulx%retics=absolute retics/ul
When can errors happen during blood collection and processing?
There can be errors at every step during
* collection
* processing
* handling/shipping
* testing
* interpretation
Color coding of stoppers
- Red: no anticoagulant, Blood is expected to clot so that serum can be harvested for biochemical profile and many other tests. (use if you want serum)
- Red and grey: “tiger top”, used to separate serum from erythrocytes (RBCs) without transferring to a different tube.
- Lavender: contains the anticoagulant EDTA so it strongly chelates Ca++, preserves cell morphology, and used to collect blood for CBC and fluids
- Blue: contains the anticoagulant sodium citrate which weakly chelates Ca++ and is used to collect blood for coagulation testing and platelet counts
- Green: contains anticoagulant heparin, used to collect blood from large animal, avian, and reptile serum biochemical panels and used for specific tests like lead concentration
- Gray: rarely used, contains sodium fluoride which inhibits glucose metabolism
heparin
an anticoagulant that prevents thrombin from promoting fibrin formation and is in the green blood collecting tubes
Technique for filling tubes
- large vein: so you do not cause vein to collapse or shearing
- sharp needle: do not want tissue plug, that will lead to clotting - do quick shot up
- let vacuum do the work: cells can lyse if you do not let it go in gently
- 20G needle or up: avoid hemolysis
* discarded blood>citrate>serum>EDTA - immediately invert anticoagulant tubes
don’t break seal on tubes with stuff in it
sample handling procedures
Blood for CBC: either analyze within one hour or make blood film and refrigerate tube (don’t refrigerate blood film- condensation causes cells to lyse).
Don’t allow to freeze, freezing lyses cells.
If blood sits at room temp for 24 hours or more, erthrocytes swell and leukocytes will degrade.
PCV
packed cell volume
sample handling
what happens if your blood sample sits at room temperature for 24 hours or more?
erythrocytes swell resulting in increased MCV (mean cell volume).
some serum enzymes are not stable and activity will be artificially low if not meausured immediately or if the serum was not stored properly.
what is the difference between serum and plasma?
plasma has free fibrinogen and is anticoagulated.
serum only has enzymes and the ions, no fibrin, fibrin is down in the clot
MCV
mean cell volume
size of cell
chelate
to create a ring-like complex, or in loose terms ‘to grab and bond to’
What is the appropriate tube to collect blood in for a serum chemistry panel?
Red tube: it does not have an anticoagulant. blood is expected to clot so that serum can be harvested for biochemical profile ad many other tests.
Red and grey blood tube
also known as sure-sep or tiger-top
used to separate serum from RBCs without trnsferring serum to different tube
What is the appropriate tube to collect blood in for a CBC?
Lavender top:
Contains the anticoagulant EDTA
(ethylenediaminetetraacetic acid with a potassium salt) – strongly chelates Ca++
Preserves cell morphology
Used to collect blood for CBC & fluids
blood must be mixed well to prevent clotting
What is the appropriate tube to collect blood in for coagulation testing?
Blue top
Contains the anticoagulant sodium citrate - weakly chelates Ca++
Used to collect blood for coagulation testing and platelet counts
blood must be mixed well to prevent clotting
What is the appropriate tube to collect blood in for glucose determination if going to ship and can’t spin sample?
gray top tube:
it has sodium fluoride stops (glucose) metabolism
gray tube is rarely used