Lab Tech Lab Exam 1 Flashcards
Can the CBC and thrombocyte eval tests be done in house or sent out?
Both can be done in house
Thrombocyte count can be sent out with 2 unstained blood smears
What tube is needed for the CBC and thrombocyte evaluation?
Purple top
EDTA
What should always be done to confirm automated CBC results?
Automated platelet counts should be verified by examination of a stained blood smear.
Does thrombocyte eval determine abnormalities in the primary or secondary phase of hemostasis?
Primary, mechanical
Describe, in detail, the steps for manually performing CBC and thrombocyte eval.
Make diagnostic blood smear
Should be performed within 5 hours of collection
Look in monolayer
Count average number of platelets per oil immersion field (10 fields)
Multiply average by 15,000
.
.
How can platelet clumps affect thrombocyte counts?
Platelet clumping will make the count seem low.
When reviewing a blood smear for confirmation, what area of the blood film are you most likely to see this in?
Monolayer?
Describe in details the steps for running the buccal mucosal bleeding time test.
Patient may need to be anesthetized or sedated
Upper lip tied back with gauze to expose mucosal surface
Lancet used to create a small incision in the mucosa above the premolars
Incision allowed to bleed and is blotted below (not touching!) the incision site with filter paper every 5 sec until would is no longer bleeding
Can the BMBT test be sent out to a lab?
No, only in vivo test for primary hemostasis and must be performed in house
Is the BMBT test used for primary or secondary phase of hemostasis?
Primary, mechanical
What is the normal time for the BMBT test in a dog?
1-5 min
If BMBT is prolonged, what medical conditions could cause this to occur?
Evaluates vascular integrity, platelet numbers, function, and vWF
What tube is needed for the activated clotting time test, ACT? What is in the tube?
Gray top tube
Diatomaceous earth
Can the ACT test be done in house or sent out?
In house
Is the ACT test used to evaluate the primary or secondary phase of hemostasis?
Secondary (chemical)
What portion of the coag cascade is evaluated for the ACT test?
Intrinsic and common pathways
Describe in detail the steps for running the ACT
Gray top tube must be warmed to 37C (98.6F) to evaluate clot formation
2 mls of fresh, whole blood (without anticoagulant) is added to a special tube containing diatomaceous earth as a contact activator
Invert tube gently to mix
Place tube back into heat source
What is the normal ACT time for a dog?
60-90 sec
What is the normal ACT for a cat?
45-160 sec
If ACT is prolonged, what medical conditions could cause this to occur?
Can demonstrate severe clotting factor deficiencies, but insensitive compared to PTT
What tube is needed for a Prothrombin (PT) test? What anticoagulant is present in this tube?
Blue top tube
Citrate
Can the PT test be done in house or sent off?
Either
Is the PT used to evaluate the primary or secondary phase of hemostasis?
Secondary or chemical phase
Which portion of the coag cascade is evaluated with the PT test?
Extrinsic and common pathway
If prothrombin time is prolonged, what medical conditions could cause this to occur?
Severe liver disease
DIC (disseminated intravascular coagulation)
Hereditary or acquired deficiencies of extrinsic or common pathway factors
Vit K deficiency/antagonist
Early rodenticide toxicity (within 24hrs)
What tube is needed for the Activated Partial Thromboplastin Time, PTT? What anticoagulant is present in the tube?
Blue top tube
Citrate
Can the PTT test be done in house or sent off?
Either
Is the PTT test used to evaluate the primary or secondary phase of hemostasis?
Secondary or chemical
Which portion of the coag cascade is evaluated in the PTT test?
Intrinsic and common pathways
If PTT is prolonged, what medical conditions could cause this to occur?
Deficiency of intrinsic or common pathway factors Severe liver disease DIC Vitamin K deficiency/antagonist Over-heparization
List the steps, in detail, for performing a rapid major cross match.
Major: recipient plasma and donor RBC
1 drop donor blood (EDTA), 1 drop recipient serum, 2 drops saline
Place on glass slide and swirl to mix
Equal volumes needed for accuracy
List the steps, in detail, for performing a major and minor cross match.
Obtain 1 ml of blood from recipient and place in EDTA tube
Obtain 1 ml of blood from donor and place in EDTA tube
Separate plasma from RBCs via centrifugation of both tubes, at blood speed for 10 min
Separate plasma and packed RBCs into 4 separate plastic tubes, labeled donor plasma, recipient plasma, donor RBCs, recipient RBCs
Suspend 0.2 mls of donor RBCs into 4.8 mls or 0.9% saline and gently mix
Do the same with recipient RBCs
Prepare 4 slides as follows:
(1) 1 drop donor plasma, 1 drop donor rinsed RBCs
(2) 1 drop recipient plasma, 1 drop recipient rinsed RBCs
(3) minor: 1 drop recipient rinsed RBCs, 1 drop donor plasma
(4) major: 1 drop recipient plasma, 1 drop donor rinsed RBCs
What do you look for grossly in most species, to determine if cross match is compatible?
Agglutination
If agglutination is present, what must you differentiate microscopically?
Agglutination must be differentiated from rouleaux formation
