Final Exam Flashcards
What is the Differential Calculation Equation?
WBC # from CBC machine converted from decimal to whole number X Individual WBC % in decimal form = individual wbc per microliter
Example:
CBC machine #: 9.2
Segs from counter: 53
9,200X.53=4876/ul
*Remember the total of all your individual WBC should total the WBC number you got from your cbc machine.
How to find the platelet estimate?
- Go to counting area on oil immersion
- count all platelets seen on 5 separate fields
- Divide the total # of platelets by 5 to find the average
- Multiple the average by 15,000
- Multiple the average by 18,000
- Both answers from 4 & 5 gives the range of platelets/ul
Where do you find platelet clumps?
Look at the feathered edge at 10x for platelet clumps
What is the minimum amount of platelets needed for adequate clotting?
50,000 platelets/ul
Frequency & Volume of Donation: Cats & Dogs
Felines: 30-50 ml of blood per month for the average cat donor (Over 5lbs)
Canine: 5-10 ml per pound of body weight of donor
Rate of Transfusion:
◦ 1-5 ml per minute
◦ Calculate proper volume
◦ Warm Blood up to 38C in water bath to prevent ventricular arrhythmia
◦ Stop immediately if any signs of reaction
◦ If transfusion is given to fast can cause Cardiac overload
Coagulation Testing:
• These types of tests are ran when we are concerned the animal has prolonged bleeding time/Diffculty creating a blood clot.
Von Willebrand Disease (vWD) is a Common genetic disorder in which breed:
Doberman Pinschers
Intrinsic Factors:
Platelets, Fibrinogen, Prothombin.
• Fibrinogen: Beta Globulin Plasma Protein
• Prothrombin is the inactive form of Thrombin
• Fibrinogen + Thrombin create the Fibrin Threads
Extrinsic Factors
Collagen & Thromboplastins
Intrinsic Coagulation Tests
‣ Activated Partial Thromboplastins Time (APPT)
• Evaluates intrinsic and common clotting mechanisms
• This is not done in house at the vet clinic but sent to an outside lab
• Use the Blue Top Tube (BTT) for blood draw: Contain Sodium Citrate that is an anticoagulant that can be reversed at the lab allowing for them to measure how long it takes for the blood to clot once the Sodium Citrate has been removed.
◦ This blue top tube is ONLY used for clotting not for cell morphology or anything else only to evaluate clotting.
◦ If you are drawing multiple tubes: Blue Top Tube is always FIRST.
‣ Activated Clotting Time (ACT)
• Evaluated intrinsic and all significant clotting factors expect clotting factor number VII (7).
• Can be sent to an outside lab where they will use an automated analyzers but can be done in clinic/in house.
• ACT Tube/Brown Top Tube is used as it contains diatomaceous earth to accelerate clotting time.
◦ Diatomaceous Earth is also used in pest control
• Warm the ACT tube to 37C in a warm water bath
• Need a min of 2 ml of blood going directly into the ACT tube via the vacutainer and once the blood hits the ACT tube you immediately start timing for how long it takes for a blood clot to form
◦ If no Clot forms: Observe after 60 seconds in a warm water bath & Observe every 5 seconds until clot is formed.
• Normal Values: 60-90 seconds
• Cascade of coagulation disorders and severe thrombocytopenia prolong clotting times
‣ Whole Blood Clotting Time
• Older test - evaluates intrinsic clotting mechanisms
• ACT test is more sensitive and more commonly used
◦ Extrinsic Coagulation Test:
‣ One Stage Prothrombin Time (OSPT)
• AKA Prothrombin time (PT) Test
• Evaluates extrinsic factors
• This will be sent to an outside lab where an automated analyzers is used.
• Prolonged prothrombin time may be associated with severe liver disease, DIC, &/or hereditary or acquired deficiencies of any factors of the extrinsic coagulation cascade.
◦ Buccal Mucosa Bleeding Time
‣ Usually done under sedation as this is when you stick the animals gums and time how long it takes for the bleeding to stop.
‣ Used to detect abnormalities in platelet function
‣ This technically is evaluating intrinsic factor
‣ Animals should be sedated and/or anesthetized
‣ Normal bleeding time for domestic animals is: 1-5 minutes
‣ Thrombocytopenia can cause prolonged bleeding times and will require a platelet count to confirm
Approximate Keeping Time of EDTA Blood:
