What are the purposes for blood chemistry testing?
to evaluate organ-systems
to identify metabolic problems
to assist in diagnosis
to assist in prognosis
to monitor therapy
What does "garbage in, garbage out" mean?
you can run anything in the machine and the machine will give us numbers. we have to make sure we are putting in the correct sample (whole blood, serum, plasma)
Can you freeze whole blood?
no, the cells with lyse when they defrost
Which is better to use, heparin or EDTA? Why?
it affects fewer test results
What about the blood can affect the blood chemistry tests?
What does the term analytes mean?
correct term for "blood chemistry"
If we can't run a blood chemistry sample immediately, what should we do?
label and refrigerate
Once we collect the blood for a blood chemistry test, what do we do right away?
separate the cells
either centrifuge (for heparin) or let clot for 30 minutes (for serum)
What can centrifugation do to the blood?
may cause hemolysis if tubes are not balanced
How long should we let the blood spin?
at least 10 minutes
What is the Stat spin?
spins a smaller sample, faster
What does hemolysis look like?
red tinge to the plasma/serum
If there is hemolysis, what will automatically increase?
What can cause hemolyzed samples?
excess pressure during venipuncture/drawing the sample too fast
shaking the blood while mixing it
pushing the blood through a needle twice
putting the blood too fast in the tube
having moisture in the tube/syringe (from reusing syringes)
What usually causes lipemia?
What are some diseases that may produce lipemia?
How do we avoid a sample being lipemic?
fast the patient overnight
What is ultracentrifugation?
spins fast enough so that the fat in the blood settles in the bottom
What are some common sources of error in testing?
errors in technique
clerical errors (interpreting numbers)
What is the quality control we do for our blood chemistry machines?
control and calibration
What is control sera?
a test we can buy that has a known value that we can run a control test on
Are calibration and control the same thing?
Do most blood chemistry machines calibrate themselves?
Other than control and calibration of our machines, what else can we do to make sure our machines are working properly?
split a sample, run half in house and send half out then compare results
What is the main benefit of running blood chemistry tests in house?
get fast results while the animal and client are still in the clinic to be able to start treatment right away which will help us practice better medicine because we will know what we are treating instead of making a guess while waiting for the blood work to come back
What are stix tests?
screening test like the glucometer
What do stix tests mostly test for?
BUN and glucose
What kind of blood can we use for stix tests?
Are stix tests fast?
What are some examples of stix tests?
mix sample on a tablet and look for a color change
not used often because few tests are available
Are blood chemistry test machines expensive to buy?
How do we choose which blood chemistry machines we buy for our clinic?
what tests do we want to be able to run
equipment investment (cost per test)
technical help (some companies are better about providing technical help so are not)
What are the three major blood chemistry manufacturers for veterinary medicine?
What was the first dry chemistry test from Idexx?
Describe the VetTest. Serum, whole blood, or plasma? How much? How many tests can be run? How long until results?
21 tests (slides)
Describe Idexx Catalyst Dx. How many tests can be run? Serum, whole blood, or plasma? How many clips are preloaded?
serum or plasma
6 preloaded clips
What are the special tests that the Catalyst Dx can run that other machines can't?
Urine protein:creatinine ratio
What does the urine protein:creatinine ratio test?
assesses protein loss
What does the VetStat test for?
runs electrolytes and blood gases
What clinics do we usually see the VetStat in?
equine and emergency clinics
Describe Scil Reflovet Plus. What sample (whole blood, serum, plasma)? What is used to test? How many tests can be run? How much blood is needed? How long do tests take?
can use whole blood, serum, and plasma
single test strips
15 tests can be run
2 - 3 minutes
Describe the Scil Spotchem EZ. How many tests can be run? What can be used for the sample? What is used to test?
19 different tests, 9 can be run at once, offers 6-test multistrip
Serum, plasma, whole blood
strip (look like urine strips)
Describe Dri-Chem 7000. What does it use to test? How many tests can be run? How long does it take to run a test?
can run single tests or 5 panels at a time
5 panels takes 16 - 30 minutes
Describe VitalPath. What does it test? How much blood do you need for the sample? What can be used (whole blood, serum, plasma)? How long does it take to run a test?
blood gas and electrolyte analyzer
whole blood, serum, and plasma
takes 50 seconds to run 35 parameters
How many blood chemistry machines does Abaxis offer? What are they?
Vetscan i-Stat 1 and VetScan (Classic, VS2, and VSpro)
Describe Vetscan i-Stat 1. How many tests can be run? What does it use to test? Whole blood, plasma, or serum? How long for results? What does it test for that other machines don't?
1 - 12 tests per cartridge
What kind of clinic is the Vetscan i-Stat 1 mostly used in? Why?
wildlife and large animals
it is handheld and can go out in the field
Describe VetScans (classic, VS2 and VSpro). How many tests can be run? What is used to run tests? How much blood is needed? Whole blood, serum, plasma? How long does it take to get results?
What do blood gases analyze?
p stands for pressure
When we run the blood gas machine, where do we get the blood?
whole arterial blood
How do we keep the blood sample when we are testing blood gases? Why?
keep it cold
to prevent RBCs from converting O2 into CO2
When we are running a blood chemistry, what are we looking for?
an increase or decrease of values for specific organs
How do we know which blood chemistry tests to run?
evaulate the patient's history and clinical signs
What are routine blood chemistry tests that we run for non-sick patients?
Scil Reflovet Plus
What is the functions of a kidney?
remove nitrogen waste
regulate salt ions
regulate acid-base balance
regulate RBC production in bone marrow
regulate blood pressure
conserve blood glucose
elimination of drugs/toxic substances
an increase in nitrogenous waste (BUN, creatinine) in the blood
What can an increase in nitrogenous waste (BUN, creatinine) be?
Azotemia occurs when _____ of the glomerulus stops working.
What does GFR stand for?
glomerulus filtration rate
What causes prerenal azotemia?
kidneys are not getting perfused.
What are some clinical signs of prerenal azotemia?
urine SG increased
What does it mean "kidneys are not getting perfused"?
blood is not coming to the kidneys like it should
Is GFR increased or decreased with prerenal azotemia?
Are BUN and creatinine values increased or decreased with prerenal azotemia?
What will happen if prerenal azotemia is not treated?
will turn into renal azotemia
How do we treat prerenal azotemia?
Once we increase perfusion to the kidneys, will prerenal azotemia go away and the BUN and creatinine values go back to normal?
What is renal azotemia?
kidneys are being destroyed
chronic renal disease
What percent of the nephrons are non-functional with renal azotemia?
When does renal azotemia occur?
usually occurs after lose ability to concentrate urine
specific gravity isosthenuric (same as blood)
Renal azotemia leads to what?
renal shutdown and the patient dies
What usually causes postrenal azotemia?
urinary blockage or post-renal leakage
blocked urethra or ruptured bladder
If we don't fix postrenal azotemia what will happen?
the patient will die
If we unblock the patient, will postrenal azotemia go away?
yes, as long as there is not permanent renal damage
What kind of patient do we commonly see postrenal azotemia?
in blocked cats
What is uremia?
increased BUN and creatinine and patient is very sick
older term for azotemia
What should the kidneys eliminiate that they don't which causes an increased BUN?
Where is in the kidney is the urea filtered?
Passive tubular reabsorption should absorb how much urea?
The longer filtrate is in the tubules, the _____ will be reabsorbed.
GFR is dependent on _____
_____ perfusion causes _____ GFR with causes urea to stay in the blood
The _____ perfusion, the longer it will take to pass thru tubules which causes _____.
What kind of sample do we use for azostix?
What kind of sample do we need to test BUN in machines?
serum or plasma
What will lipemia do to BUN values?
falsely elevate BUN values
What kind of contamination will cause an increase in BUN?
How is creatinine formed?
be degradation of creatine
Creatine comes from what?
muscle - energy source
Where is creatinine filtered? Is there any reabsorbtion/
filtered at glomerulus, no tubular
What is a more accurate measurement of GFR, BUN or creatinine?
When creatinine is increased, is the prognosis good?
no, it is harder to decrease and prognosis is poor
What kind of sample do we use to test for creatinine?
serum or plasma
What can falsely elevate creatinine levels?
What is phosporus?
Where is phosporus filtered?
normally freely filtered at glomerulus
Decreased GFR will _____ phosporus.
What will phosporus do when there is renal disease?
What often happens with non-regenerative anemia?
chronic renal failure
Why does chronic renal failure cause non-regenerative anemia?
because of the decrease production of erythropoietin
GI ulceration/bleeds and will decrease RBC lifespan due to azotemia
bone marrow is also suppressed
What causes hypoalbuminemia?
loss of albumin at glomerulus
When there is hypoalbuminemia what kind of protein do we see in the urine?
increase in protein
When there is renal disease there is _____ of albumin
What is the largest gland in the body?
What is cell necrosis of the liver?
break down of liver cells
What is cholestasis?
slowing of passage of bile
What kind of problems can cause jaundice/icterus?
liver or hemolysis problems
If you have enough hemolysis to cause icterus then the patient will be _____. What kind of test can we use to rule this out?
What is total bilirubin?
the amount of indirect (unconjugated) and direct (conjugated) bilirubin added together.
If there is an increase in indirect (unconjugated) bilirubin, what does that mean?
If there is an increase in direct (conjugated) bilirubin, what does that mean?
What can total bilirubin cause?
What is conjugated bilirubin?
bilirubin made water soluble in order to be secreted in the urine
What kind of bilirubin do most blood chemistry tests test for?
What is stercobilinogen?
gives us the brown color of feces
Increased bilirubin will cause increased _____.
Which test is better for testing liver disease, bilirubin or bile acids?
Bile acids tells you something is wrong with the liver, but what does it not tell you?
what is wrong with the liver
Bile acid is _____ in most liver disease.
What do ammonia tests test for?
liver-brain syndrome (aka hepatic encephalopathy)
When do we see increased ammonia tests?
What will a clinical sign most likely be with dogs with porto-systemic shunts?
Why is ammonia increased with port-systemic shunts?
liver is not converting the ammonia to urea and is getting in the brain
What are some reasons why enzymes can be increased?
What are the different enzymes we test for?
Which enzyme is most useful to test for liver disease in dogs and cats?
Which enzyme will be increased with a swollen liver?
Which enzyme will be increased due to an increase in muscle activity?
Which enzymes increase with cholestasis?
What is the BSP clearance?
only test that tests live function and tells how much the liver is functioning at that specific time
How do you do the BSP clearance test?
inject dye IV then collect the blood after 30 minutes
Where is cholesterol synthesized?
primarily by the liver but can be distributed elsewhere
What are some things that would cause cholesterol to increase?
Where is cholesterol produced?
in the liver
Which enzymes are in the exocrine pancreas?
What causes amylase and lipase to increase?
What is amylase?
enzyme that breaks down startch
What is lipase?
enzyme that breaks down fat
What is trypsin?
enzyme that breaks down protein
When will trypsin be decreaed?
How do we measure trypsin?
x-ray film test - stick x-ray film in watery diarrhea, if the x-ray film turns clear then there is trypsin present
What does the endocrine pancreas do?
Which pancreas enzymes should be run together?
amylase and lipase
What is the Serum Trypsin-like Immunoreactivity Test (TLI/STLI)?
determines pancreatic insufficency by detecting trypsinogen in serum.
What do low values of the Serum Trypsin-like Immunoreactivity Test indicate?
reduced pancreatic mass
Where is amylase found?
pancreas and duodenum and saliva
If amylase is increased what does that mean?
pancreatic leakage (pancreatitis)
What can affect the results of an amylase test?
hemolysis falsely elevates
lipemia may reduce
Where is lipase found?
How is lipase eliminated from the body?
by the kidneys
What kind of tube should we avoid when collecting blood to test for amylase and lipase?
EDTA (purple top)
What can decrease lipase levels?
hemolysis and lipemia
What is CK (CPK)?
enzyme in the muscles
When does CK enyzme increase?
degenerative/necrotizing muscle injury: myositis, IM injections, poor venipuncture, vigorous exercise, electric shock
Is CK a very stable enzyme?
What does CK stand for?
What other enzyme is found in muscle?
What can cause CK to be falsley elevated?
delay in assay
Is it a problem if glucose is increased or decreased?
How can we test glucose?
Can the signs for hypoglycemia and hyperglycemia be similar?
If a patient is fasted, the glucose test using capillary blood is _____ than venous blood.
2 - 5 mg/dl
If post-prandial, the glucose test using capillary blood is ____ than venous blood.