Harvey Chapter 2 Hematology Procedures AKG Flashcards
Calculate the blood volume of a 4kg cat knowing total blood volume accounts for approximately 7% of body weight in cats.
You can only safely remove ___% of the blood volume from an animal.
.07 x 4kg = 0.28 kg
1 mL = 1 g
0.28kg * 1000g/1kg = 280g * 1ml/1g = 280 mL
you can remove 20% –> .20 x 280 = 56 ml
Why is it easier to detect methemoglobin when looking at an oxygenated blood sample (e.g., arterial vs venous)?
In a venous blood sample, blood contains deoxyhemoglobin, which gives it a darker color and easily blends with methemoglobinized blood. In an arterial sample, the blood is oxygenated (oxyhemoglobin), imparting a bright red color. Increased amounts of methemoglobin in arterial blood will result in noticably darker blood.
Describe the spot test to detect methemoglobin
Using venous blood, place one drop of venous blood onto absorbant white paper and one drop of control blood next to it. The blood gets to oxygenate, and if the patient has methemoglobin content > 10%, you will be able to see the blood have a noticeably brown color comapred to the bright red color of control blood.
Which type of immunoglobulin is most commonly responsible for RBC agglutination?
IgM
What is a rapid way to differentiate rouleaux from agglutination?
Mix five drops of physiologic saline with a drop of anticoagulated blood on a glass slide and examine it as a wet mount using a microscope. The dilution reduces rouleaux, but agglutination should not be affected.
What would give a buffy coat a reddish appearance?
marked reticulocytosis
Plasma is clear in most species, except it is light yellow in ____.
horses - they naturally have higher bilirubin concentrations
cattle - depending on diet (carotenoid pigments)
Plasma protein concentrations are ____ in in newborn animals compared to adults.
lower
How do you estimate fibrinogen?
Heat precipitation test - when plasma is heated to 56-58C for 3 minutes, fibrinogen precipitates and the plasma is debfibrinogenated. Substract TP measurmenet from defibrinogenated plasma from pre-heated plasma to get an estimate of fibrinogen.
______ has been infused into the peritoneal cavity of horses and cattle in an attempt to prevent abdominal adhesions after surgery. This material can appear as a precipitate between cells in blood that resembles stain precipitate.
Carboxymethylcellulose
When making a blood smear, the ___ the angle and the ____ the speed of spreading, the thicker and shorter the blood film will be.
Greater and faster
____ is an anticoagulant that can cause marked hemolysis in some species of birds (ostriches, emus, jays), reptiles (turtles and tortoises), and fish (carp and brown trout).
EDTA
*use heparin instead
What can spuriously increased hemoglobin measurmenet and therefore the MCHC calculation?
Lipemia
Heinz bodies
Precipitation of paraproteins
*NOT hemolysis - this will not increase HGB, but it will increase MCHC
How many RBCs are counted to perform a reticulocyte count on new methylene blue stained slide?
1000
What stain is used to look for iron?
Prussian blue
Iron containing erythrocytes are called ____
siderocytes
What does this basophilic material resemble within the neutrophil?
A is a Wright-Giemsa stain and B is a prussian blue
Iron
“sideroleukocyte”
In neutrophils, primary (azurophilic) granules contain _____ while secondary (specific) granules contan lipids and stain with ________.
MPO
Sudan Black B
**primary granules do stain with Sudan Black B to a lesser extent
All stages of neutrophil development stain positive for MPO. T/F
False - peroxidase activity exhibited only in promyelocyte to segmented neutrophils
*sudan black B will stain all stages of neutrophil maturation becuase it mainly stains secondary granules but will also stain to a lesser extent primary granules
Peroxidase activity in neutrophils is absent in which species?
Certain berds
Rabbits
Reptiles (except Iguanas)
Eosionphils stain positive with peroxidase except in which species?
Cats
Which two cytochemical stains are specific for eosinophils?
Luna
Luxol fast blue
Which cytochemical stain is best to ID monocytic or myelomonocytic leukemia over granulocytic?
NSE - nonspecific esterase
When using cytochemical stains to differentiate the type of acute leukemia, and the cells are negative for peroxidase and sudan black, what are your ddx?
Which stain would you do next and why?
Acute lymphoid leukemia, acute undifferentiated leukemia, and acute megakaryoblastic leukemia
Acid Phosphatase - will focally stain within T-ALL and diffusely stain with megakaryocytic leukemia
