Additional Tests Flashcards
Why do we perform a Bone Marrow Evaluation?
For diagnosis and prognosis in specific cases
What changes do we see on a CBC that leads us to run a Bone Marrow?
Persistent unexplained pancytopenia, neutropenia or thrombocytopenia, and nonregenerative anemia
Abnormal morphologic changes or unexplained immature cells
What two methods are used to collect bone marrow
Aspiration
Removal of bone marrow core
Who performs the bone marrow collection?
Veterinarian
What is the role of the veterinary technician in bone marrow collection?
Restraint, general anesthesia, or sedation and local anesthesia, sending out quality samples
Aspiration biopsy
Head of femur or humerus
Rotated and pressure applied
Attach syringe and aspiration
Core biopsy
Sometimes provides a better quality sample
Use different sites if done in conjunction with aspiration biopsy
Rotate needle to cut a piece of bone from the cortex
Preparing Bone Marrow Smears
Multiple slides for various preparation techniques
Must be made immediately if not mixed with EDTA
Aspirate sample prepared like blood smears
Stain with Romanowsky-type stain
What are the different types of smears used to prepare bone marrow?
Line, starfish, and compression smears
When evaluating bone marrow slides, what must you have?
A differential WBC count from a concurrent peripheral blood
What is normal bone marrow evaluation for an adult animal?
50% nucleated cells and 50% fat
What is normal bone marrow for a juvenile animal?
75% nucleated cells and 25% fat
What is normal bone marrow for a geriatric animal?
25% nucleated cells and 75% fat
Slide examination on a microscope
4x: focus
10x: number and distribution of cells
40x: general evaluation
100x: cell differentiation (TOUGH)
Myeloid : Erythroid ratio
cells that are going to be WBC : cells that are going to be RBC
500-1000 nucleated cells are counted
What is a normal myeloid to erythroid ratio?
close to 1:1
What is an abnormal myeloid to erythroid ratio?
increase in WBCs and decrease in RBC or opposite
What are abnormalities classified by?
Cell number and cell morphology
What are abnormalities characterized by?
Hypercellular and Hypocellular
Absent= Aplastic
What is the main goal of bone marrow evaluation?
To determine if the abnormalities are being caused by an inflammatory process or neoplasia (leukemia)
Who is responsible for the diagnosis in bone marrow evaluation?
the pathologist
Erythrocyte Sedimentation Rate
The rate red blood cells fall in their own plasma will be altered in some disease states
Erythrocyte Sedimentation Rate Manual Method
Calibrated tube filled with fresh EDTA-treated blood
Place in rack that is perpendicular to table
Allow to sit undisturbed at room temperature for 60 mins
Record the level of the top of the RBC column
If performing the erythrocyte sedimentation rate for horses how long do you wait?
20 minutes
Erythrocyte Osmotic Fragility
Test of the ability to withstand hemolysis in varying concentrations of saline
Not routinely performed
