Hematology Test 2

different tests require different tubes / systems

why is it important to know the test(s) being run?

3

always collect enough sample to run the test __ times whenever possible

largest

always use the _________ (largest or smallest?) needle for your patient size

choose the syringe closest to the required sample volume

how do you choose syringe size?

veterinarian & lab (if necessary)

who should you check with to make sure you collect the sample correctly & use the correct supplies?

true

true or false: with the vacuum system, you can collect multiple tubes at once

a needle, needle holder, and collection tubes

what is the vacuum system composed of?

sizes; chemical

with the vacuum system, many tubes are available in various ______ & ___________ makeup

manual method

collection method standardly performed in practice

needle, syringe, and collection tube of choice

what is used for the manual method of blood collection?

true

true or false: always remove needle & cap of tube to transfer sample

due to longer draw time / distance & clotting issues

some veterinarians recommend using a butterfly catheter to draw blood, especially in cats; why is this less desirable?

crenation

the process where cells, particularly red blood cells, shrink & develop abnormal, notched, or scalloped edges

jugular vein; cephalic vein

which vein is best for blood collection in most mammals? which is the next best?

femoral / medial saphenous vein

which vein is best for blood collection in cats?

peripheral or capillary

__________ or __________ blood samples from birds & lab animals are best

false

true or false: it is ideal to draw blood after treatments / procedures

anticoagulants

any chemical that prevents or delays coagulation

false

true or false: always vigorously mix samples

based on the test(s) to be run

how do you choose which type of anticoagulant is needed?

prevents conversion of prothrombin to thrombin during clotting process

how does heparin work as an anticoagulant?

heparin

anticoagulant choice for most plasma samples

differentials - hinders proper staining of WBCs

what should heparin never be used for? why?

sodium, potassium, lithium, or ammonium salt

heparin is available as…

true

true or false: for small sample volumes, you can coat the inside walls of a syringe with liquid heparin before sample is drawn

heparin

EDTA

best anticoagulant for morphology & cell analysis

plasma samples for chemistry

EDTA is not ideal for…

prevents clotting by binding with calcium

how does EDTA work as an anticoagulant?

crenation

excess EDTA causes cellular _________

EDTA

ethylenediaminetetraacetic acid

what does EDTA stand for?

sodium, potassium, ammonium, or lithium salts

oxalates & citrates are available as…

by binding with calcium & other clotting factors

how do oxalates & citrates work as anticoagulants?

oxalates

_______ may bind to metallic ions necessary for enzyme activity

false

true or false: you always want to use potassium / sodium based oxalates or citrates for potassium / sodium chemistry

sodium citrate

sodium fluoride

the best anticoagulant for glucose preservation

6 - 10mg/ml

as an anticoagulant, sodium fluoride is used at __-__ mg/ml of blood

glucose

sodium fluoride can be aded to other anticoagulants to preserve _________

can interfere with many serum chemistries

what is a limitation to sodium fluoride?

sodium fluoride

none - contains no anticoagulant

what type of anticoagulant is in plain top / serum separator tubes (SSTs)?

serum

plain top tubes are best for collecting…?

to aid with separation of the sample

what is the purpose of the gel in SSTs

true

true or false: the gel in SSTs may interfere with certain sensitive chemistries

1

refrigerate whole blood within __ hour(s) of collection

false - allow sample to reach room temperature first

true or false: whole blood samples should be analyzed immediately after being removed from the fridge

true

true or false: refrigerated samples of whole blood should be mixed gently

hemolysis

why should you not freeze whole blood samples?

1

plasma samples should be refrigerated or centrifuged within __ hour(s)

true

true or false: you can freeze collected plasma, just not the whole tube of blood

false! - do NOT invert the tube afterwards

true or false: after centrifuging plasma samples, you want to mix gently

bring sample back to room temp & mix gently

what should you do with a plasma sample after refrigeration, but before centrifugation?

30

for serum samples, allow to clot for __ minutes, then centrifuge

true

true or false: you can freeze serum after centrifugation

right jugular vein

• largest

• easiest to reach

• not contaminated with lymphatic fluid

which vein is preferred for sample collection from exotics? why?

they can provide more accurate numbers of blood cells; more than just an “estimate”

why are automated cell counters useful?

1. impedance analyzer

2. laser flow cytometry

3. quantitative buffy coat analyzer

what are the 3 main types of automated cell counters?

false - some machines may combine 1 or more of the types

true or false: each automated cell counter machine is limited to one type

complete blood count

what does CBC stand for?

• automated analyzer

• manual PCV / TS (+/- fibrinogen)

  • always check for microfilaria!

• manual differential

  • diff of 100 WBCs, RBC morphology, PLT count, blood parasites

what do most veterinarians expect in a CBC?

hemogram

CBC, aka…

• quantitative data

  • usually a definitive #

  • total cell counts, differential counts, red cell indices

• qualitative data

  • more subjective

  • cellular morphology

what are the 2 portions of a hemogram?

1. acute

2. chronic

3. overwhelming

what are the 3 ways to classify inflammation?

patient history

what can be helpful to differentiate the classifications of inflammation?

• neutrophilia with a left shift

• lymphopenia

• variable monocytosis

what is found with acute inflammation?

use of cells by blood & tissues

neutrophilia reflects…

depletion of the marrow pool & younger cells are released

left shift suggests…

stress related to an acute inflammatory process

lymphopenia reflects…

• marked leukocytosis

  • marked neutrophilia with left shift

  • neutrophil toxicity

  • monocytosis

• normal to slighly elevated leukocyte count

  • normal lymphocytes & monocytes

what is found with acute chronic inflammation?

anemia & hyperglobulinemia

marked leukocytosis is often accompanied by…

an increase in production due to demand; no longer utilizing immature cells, so there is no longer a left shift

normal WBCs reflect…

a need to phagocytosis

monocytosis reflects…

• reduced neutrophils

• left shift

• lymphopenia

• variable monocytosis

what is found with overwhelming inflammation?

WBCs

the immune system becomes overwhelmed / exhausted as _____ are used up

• mild neutrophilia

• mild monocytosis

• mild lymphocytosis

as the body prepares for fight / flight, it may cause…

eosinophils & lymphocytes

stress may reduce numbers of…

mild lymphocytosis

what is often found in cats that are stressed?

demand for phagocytosis

what do monocytes indicate?

• acute or chronic inflammation

• tissue necrosis

monocytosis is present in what processes?

persistent eosinophilia and / or basophilia

what WBC abnormalities are seen with hypersensitivity?

parasitic disease, allergies, feline asthma, allergic gastroenteritis

list 4 causes of hypersensitivity

histamine

what chemical mediator is associated with hypersensitivity?

false - most hemoparasites (ex. Mycoplasma) do not cause eosinophilia

true or false: all parasitic infections are associated with eosinophilia

heartworm (Dirofilaria immtis)

a common parasitic cause of eosinophilia in dogs

ectoparasites or those with a migrating tissue phase

what specific type of parasitic infection is associated with eosinophilia?

toxic neutrophils (and lymphocytes)

toxemia is characterized by…

bacterial infections

toxemia is most commonly associated with…

extensive tissue necrosis

what tissue condition may correlate with toxemia?

true

true or false: you can have neutrophils toxicity without having toxemia

1. maintain vascular integrity

2. stop bleeding by forming plugs.

3. facilitate secondary hemostasis (coagulation) & fibrin formation

4. promote vascular healing

what are the 4 distinct functions of platelets?

bone marrow

where are platelets produced?

thrombopoietin

what is the cytokine involved with PLT development?

2/3 to 3/4

approximately ___ to ___ of all platelets are in circulation

• 3 - 7 days

• phagocytized

1. what is the average life span of platelets?

2. how are they removed from the body?

evaluate by counting the # of PLTs in a minimum of 10 field (100x) & average them together

describe how to evaluate PLTs on a blood film

oil immersion field

what does “oif” stand for?

10 - 12 / oif

how many PLTs / oif is considered normal?

PLT #s seemed decreased; if so, then more quantitative measures should be done

examination of PLTs on a blood film is sufficient unless…?