Clinical Pathology Flashcards
1
Q
Name the three components of a CBC
A
Erythron
Leukon
Thrombon
2
Q
What measurements express RBC mass within a sample?
A
RBC count
Hgb (Hemoglobin)
HCT/PCV
3
Q
How is HCT measured?
A
Calculated by a machine
PCV is calculated by hand
4
Q
MCHC measures…
A
Hemoglobin concentration (hypochromic, normochromic, hyperchromic)
5
Q
MCV measures…
A
RBC size (macrocytic, normocytic, microcytic)
6
Q
How can we measure regeneration?
A
Reticulocyte count
Reticulocyte %
CHr
Morphological changes
7
Q
Typically, Hgb is ____x the value of hematocrit
A
3x +/- 1-3 units
8
Q
Eosinophilia/basophilia are associated with…
A
Worms, wheezes, weird diseases
9
Q
What does a stress leukogram involve?
A
Neutrophilia
Lymphopenia
Hyperglycemia
10
Q
Lyphocytosis may be encountered with _________ inflammation or an epinephrine leukogram
A
Chronic
11
Q
When may you see a neutropenia?
A
Overwhelming inflammation
12
Q
The best way to assess platelets is through a _____________________
A
Direct smear
13
Q
Platelet clumping causes a _____________
A
Thrombocytopenia
14
Q
How can we screen for coagulation disorders?
A
PT/PTT
Probably also buccal mucosal bleeding time but idk
15
Q
You get a chemistry that doesn’t include globulins, what do you do?
A
TP - Albumin = Globulin
16
Q
How can you determine whether an elevated fibrinogen is due to dehydration or inflammation?
A
(Plasma Protein - Fibrinogen)/Fibrinogen = PP:F ratio
17
Q
What are the values for inflammation and dehydration when interpreting PP:F ratio in horses and cows?
A
Horses: <15 inflammation, >20 dehydration
Cows: <10 inflammation, >15 dehydration
18
Q
What might serum protein electrophoresis be useful?
A
An unexplained protein elevation
Polyclonal = Inflammation
Monoclonal = neoplasia
19
Q
What two CHOs do we commonly measure?
A
Glucose
Fructosamine (diabetic patients)
20
Q
What lipids are commonly measured?
A
Cholesterol
Triglycerides
Ketones
NEFAs
21
Q
Primary renal markers/tests
A
Creatinine
BUN
Urinalysis (UPC)
SDMA (earlier marker)
22
Q
3/4 loss of renal mass will result in __________; 2/3 loss of renal mass will result in ___________
A
Azotemia; Isosthenuria
23
Q
What are secondary measurements of renal function?
A
Albumin
Minerals (Phosphorus)
Electrolytes
Acid-Base
24
Q
What minerals do we commonly measure?
A
Calcium
Magnesium
Phosphorus
25
T/F: Ionized calcium concentration is affected by acid-base balance and albumin levels
True
26
Why do we correct chloride?
To determine if a change in chloride is d/t free water or an acid-base disturbance
Modify the results to take into account changes in sodium (which reflects free water) and chloride is a simp for sodium
27
What is the calculation for corrected chloride?
(Average/Measured Na) x measured Cl
28
Name some of the markers of liver injury
ALT
AST
GDH
SDH
LDH
29
Name some markers of liver function
Albumin
BUN
Glucose
Cholesterol
Coagulation factors
Conjugated bilirubin
Fibrinogen
Ammonia
Bile acids
RBCs
- Someone taught me GUAC (Glucose, Urea, Albumin, Cholesterol)
30
Name some markers of cholestasis
ALP
GGT
Bilirubin
31
What is the primary muscle injury marker?
CK
32
The exocrine pancreas is responsible for producing __________
Digestive enzymes
33
T/F: Lipase and amylase are incredibly specific to the pancreas
False - produced elsewhere in the body
Increase with pancreatic damage or decreased GFR (eliminate by the kidneys), but there are better enzymes to diagnose pancreatic disorders
34
TLI (Trypsin-like immunoreactivity) is primarily used for the diagnosis of ____________
Exocrine Pancreatic Insufficiency (EPI)
35
What causes an increase in TLI or PLI?
Acinar pancreatic damage
Decreased GFR
36
Are low levels of PLI and TLI significant?
Yes, may indicate chronic pancreatitis and acinar atrophy
37
T/F: Reference intervals are standardized across the globe for each species to allow for better communication between veterinarians and reference labs.
False - Reference intervals are very specific for the equipment you use, the species you are studying, the area you live in, etc.
38
How is a reference interval established?
Sample size of ideally 120 individuals that are representative of the population of interest
Establish the mean +/- 2 SD
39
What are the three potential sources of laboratory error?
Pre-analytical
Analytical
Post-analytical
40
T/F: Most laboratory errors are analytical
False - 46-68% are pre-analytical
41
Name some examples of pre-analytical errors
Inappropriate test request
Order entry error
Labeling error
Inappropriate container or sample
Insufficient volume
Inadequate transport or storage
Sample processing before analysis
42
What are some ways we can limit pre-analytical errors?
SOPs
Training
Better communication
43
Name some examples of analytical error
Instrument malfunction
Reagents
Methodology
Operator Error
44
How can we limit analytical errors?
SOPs
Training
Automation
Monitoring results
Certification
45
Name some examples of post-analytical error
Failure in reporting
Improper data entry
Inappropriate reference intervals
Incorrect interpretation of results
46
How can we limit post-analytical error?
SOP
Training
Automation
Better communication
47
A 3 year-old DSH NM presented to you 2 days ago for a urinary obstruction. You successfully unblocked him, but recommended hospitalization for 24-48 hours to monitor his urine output and kidney values. When submitting a blood sample for a chemistry, the blood was only put into a purple top tube and submitted. What kind of error is this?
Pre-analytical
48
You recently purchased your practice from some old fart who didn’t believe reagents could ever expire. After running a CBC in-house and receiving absolutely ridiculous results, you realize the reagent you used expired in 2012. What kind of lab error is this?
Analytical
49
When inserting lab results into a patient’s chart, you (a lab technician) accidentally enter creatinine as 9.0 instead of 0.9 g/dL (RI 0.4-1.4). The veterinarian calls you frantic because the pet is showing no signs of acute kidney injury. What kind of error would this be?
Post-analytical
50
What is the best way to collect a blood sample?
Vacuum!
Syringe and needle have a higher change of damaging cells
51
You are presented with a chronically vomiting PU/PD 12 year-old cat. You decide to submit a CBC/Chem and UA to the lab. On the order form, you write “ADR” in the history section because you’re in a rush and you are fairly confident it’s got CKD. When you go to drop off the sample, the lab technicians give you a side eye. Why?
Shitty history duh
52
T/F: the best way to pick what container you submit your sample to the lab in is by choosing your favorite color.
False - different containers serve different purposes and are specific to certain tests (Ex. CBC - Purple/Green, Chemistry - Red/Yellow/Green)
53
The presence of Heinz bodies in a blood sample may lead to increased…
MCH
MCHC
Reticulocyte
Platelets
54
How can EDTA affect a sample?
EDTA is a large molecule and increases osmolarity within a sample. Increased osmolarity causes cells to shrink!
55
How might time affect your leukon?
Old samples - increased Dohle bodies, decreased WBC, decreased neutrophils, increased bands, increased lymphocytes
56
Explain how clumps, ghost cells, and organisms influence platelet count
Clumps - thrombocytopenia
Ghost cells - thrombocytosis
Organisms - thrombocytosis
57
How does hemolysis affect analysis?
Increased MCH, MCHC
Decreased PCV/HCT/RBC#
Increased platelets (ghost cells)
Increased CK (intra RBC enzyme)
Increased P
Increased AST, LDH, Mg
58
T/F: Icterus doesn’t interfere with a CBC, but can interfere with spectral properties.
True - falsely decreased creatinine and total protein
59
What are some causes of lipemia?
Triglycerides
Post-prandial sample
Pathologic
60
How does lipemia affect sample interpretation?
Changes in light scattering
TP by refractometry affected
Increased platelets (lipid droplets)
Increased Hgb
61
You leave a urine sample on the counter over the weekend, but don’t feel like calling the owner to ask for another.
1. What kind of error is this?
2. What changes might you see on the UA?
1. Pre-analytical
2. Increased pH, microbial proliferation, degradation of formed elements, degradation of chemical analytes, Ca oxalate and Mg ammonium phosphate crystals may develop
62
When preparing a slide, at what point should you put on gloves?
Before, during, and after smearing
63
You FNA a lump on the flank of a 10 year old lab. You obtain 4 samples. What do you do next?
Pre-stain one slide to check cellularity
Submit remaining unstained
Do not heat fix
64
T/F: You run a sample in your in-house machine, but for some reason the reference interval just isn’t showing up. The best way to handle this situation is to call your bestie in another state to ask what they use for their RI.
False
65
Match the cell type to its corresponding color on the ProCyte RBC scatterplot.
RBC
A) Red
B) Purple
C) Dark blue
D) Pink
E) Aqua
A
66
Match the cell type to its corresponding color on the ProCyte RBC scatterplot.
Reticulocyte
A) Red
B) Purple
C) Dark blue
D) Pink
E) Aqua
B
67
Match the cell type to its corresponding color on the ProCyte RBC scatterplot.
WBC
A) Red
B) Purple
C) Dark blue
D) Pink
E) Aqua
Aqua
68
Match the cell type to its corresponding color on the ProCyte RBC scatterplot.
RBC fragments
A) Red
B) Purple
C) Dark blue
D) Pink
E) Aqua
D
69
Match the cell type to its corresponding color on the ProCyte WBC scatterplot.
Basophils
A) Lavender
B) Dark blue
C) Red
D) Green
E) Aqua
E
70
Match the cell type to its corresponding color on the ProCyte WBC scatterplot.
Eosinophils
A) Lavender
B) Dark blue
C) Red
D) Green
E) Aqua
D
71
Match the cell type to its corresponding color on the ProCyte WBC scatterplot.
Neutrophils
A) Lavender
B) Dark blue
C) Red
D) Green
E) Aqua
A
72
Match the cell type to its corresponding color on the ProCyte WBC scatterplot.
Monocytes
A) Lavender
B) Dark blue
C) Red
D) Green
E) Aqua
C
73
Match the cell type to its corresponding color on the ProCyte WBC scatterplot.
Lymphocytes
A) Lavender
B) Dark blue
C) Red
D) Green
E) Aqua
B
74
Why do reticulocytes spread further along the X-axis on the scatter plot than RBCs?
RNA fluoresces. Reticulocytes contain more RNA than RBCs.
Will see a pretty little cloud of purple
75
How does the ProCyte work?
1. Analyzes RBCs and PLT
2. Lyses RBCs and PLT
3. Analyzes WBCs
76
What should you do when you have heavy overlap between clouds on a scatterplot?
Look at a smear
77
ProCyte can misclassify cells in ______% of cases
15
78
A WBC run on a dog shows a lymphocytosis and monocytosis. You are immediately concerned that this patient may have lymphoma. You decide to look at a blood smear. What might you see that would change this patients prognosis immensely?
Neutrophilia and L shift
Machine mistakes bands for monocytes
79
When analyzing a WBC run on the ProCyte scatterplot, you notice an increase in granularity amongst WBC population. What could cause this?
Platelet clumping
80
You run a CBC on a stray kitten. The WBC run shows intense overlap between the green and aqua clouds. Why might this be? What diagnosis would you be suspicious of?
Machine counting eosinophils as basophils
Patient likely has heavy parasite burden
81
T/F: Poor separation between the purple and dark blue clouds on a WBC run indicate a left shift.
True - Neutrophils (purple) are poorly distinguished from lymphocytes (dark blue)
82
What are the pros to POC?
Quicker turnaround time
Often cost-efficient
But does require specific technology to ensure minor training and maintenance
Must be cautious w/ interpretation
83
What are some pros and cons of sending a sample to a reference lab?
Pros - QA/QC ensures better results, sample is being reviewed by a specialist
Cons - slower TAT, gotta ship it
84
What are some DDX for a moderate normocytic, normochromic anemia that is likely non-regenerative?
1. Pre-regenerative (marrow takes 3-4d to respond to anemia)
2. Reduced erythropoiesis
3. Inefficient erythropoiesis
4. ACD
85
T/F: Dohle bodies without toxic changes are cause for concern in a cat
False - Dohle bodies w/o toxic changes are normal in cats
86
Differentials for thrombocytosis?
Reactive process (inflammation)
Splenic contraction
Rebound after thrombocytopenia
87
You have a patient that appears severely dehydrated and has a HCT of 18%. What are you concerned about as you begin to rehydrate this patient?
The anemia may be way worse than what we are seeing. Once we rehydrate, the PCV will likely drop.
88
A proportional increase in albumin and globulins is suggestive of
Dehydration
89
To determine a patient’s risk of tissue mineralization, what two values can be multiplied together?
P x Ca
Values over 80-90 increase risk of calcification
