Clin Med - Intro & Bloodwork-2

drraythe's version from 2016-03-14 22:13

Serum Chemistry

Question Answer
Where is Albumin produced?In the liver!
What can Albumin measure?Liver FXN!
What czs Hyperalbuminemia?DEHYDRATION is the only cz of this
Some czs of Hypoalbuminemia are... (8)Poor diet, Diarrhea/PLE (protein losing enteropathy)
Liver Dz
Glomerulopathy/PLN (protein losing nephropathy)
Where is AST (Aspartate Aminotransferase) located? What is it an indicator of?In the MITOCHONDRIA, which means it's a marker for cellular DAMAGE! (Would have to be destroyed for the mitochondria to get out to release the AST)
Is AST specific or non-specific?Not specific! Could be liver damage, kidney infxn, myocardial infarction, or muscle damage! (bc all have mitochondria)
At what point should you start to worry about the AST levels in the serum?IT DEPENDS! in dogs, a 2-3 times ↑ would be something to look at. In CATS, however, ANY raise of AST is cz for alarm
Where is ALT (Alanine Aminotransferase) located? What is it an indicator of?It is located in the CYTOPLASM of a cell. It is an indicator of hepatocyte INJURY! NOT FXN!
If there is an ACUTE injury to the liver, explain what the levels of ALT are doing, in terms of a time frameALT levels will be at a maximum 48 hours post-acute injury
When should you start to pay attention/worry about ALT levels in a cat? Dog? & what are the half-lives like for cat & dog?CAT: Any ↑ in ALT is cz for concern-this makes sense bc the half-life is only about hours
DOG: A value 2-3 times above average is cz for concern. The half-life for a dog's ALT is about 3 days
Where is ALP (Alkaline Phosphatase) located? What is it an indicator of? (& at what levels is it significant?)It is membrane bound to the bile canalicular surface (stick outward into lumen). It is an indicator of CHOLESTASIS! (intra or extrahepatic) & usually it is relevant at levels greater than 4 times the RI (except in cats, where any ↑ is cz for worry bc the half-life for them is so short)
How do steroids affect alkaline phosphatase? Phenobarbital?Long term steroids and/or Phenobarbital will ↑ ALP. The steroids can be exogenous or endogenous.
Which enzyme has isoenzymes?Alkaline phosphatase
Tell me where AST, ALT & ALP are locatedAST: Mitochondria (think that the S looks like the inside of a mito)
ALT: Cytoplasm (ALTernative to the intracellular AST, is the intracellular ALT)
ALP: Membrane bound to bile caniculi
Where is GGT (Gamma Glutamyl Transferase) located? What's interesting about it?It is located bound to the membrane of the bile duct epithelium. Interestingly, it is very similar to ALP
When might you want to measure GGT? Explain the method.If you want to measure hepatic lipidosis in cats, you can test both the ALP & the GGT together! If the GGT & the ALP are both elevated & the ALP is more raised than the GGT, it is very indicative of hepatic lipidosis (however, most labs dont do both bc theyre so similar)
Where is BUN (blood urea nitrogen) produced? What does it indicate?Created in the LIVER, which means that it IS A LIVER FXN ASSESSMENT
When would you see an elevation in in BUN due to the kidneys (how much damage?)75% kidney damage is when BUN levels will elevate in the blood
What might be some reasons you see an elevated BUN?High protein intake/GI bleeding (blood is protein also. belly denatures protein into amino acids → nitrogen in there. hence BUN!), renal Dz (not filtering it out), dehydration (aka prerenal azotemia), exercise
What might cz a ↓ in BUN?Poor or restricted diet (not enough protein)
Liver Dz
Diuresis (czs medullary washout)
How much damage has the kidney sustained before you see a rise in creatinine?75% damage
Which breed naturally has high creatinine levels?GREYHOUNDS-BC THEY HAVE TONS OF MM
What are some reasons creatinine might be high?Renal dz, (cant clear it)
Muscle degeneration/damage
Being a Greyhound
What is azotemia? What must you keep in mind when measuring azotemia?Elevations in either BUN or creatinine (or both). You MUST evaluate USG along w/ it. Also keep in mind that it can be cz by pre-renal, renal & post-renal problems.
Where is glucose usually going to? What can glucose levels indicate?Glucose is metabolized & stored in the LIVER, which means it can be a LIVER FXN TEST!
Would hyperadrenocortisism cz high or low glucose?High (cortisol plays a role in regulating glucose & can cz insulin resistance, leading to ↑ blood glucose)
Do steroids cz high or low glucose?HIGH (induces elevated glucose levels by stimulating glucose secretion by the liver as well as reducing glucose transport into adipose & muscle cells)
Does hypothyroidism cz high or low glucose?High! (T4 plays role in glucose regulation)
How do chronic infxns/pyometra/sepsis affect blood glucose levels?It ↓ the glucose, bc the neutrophils are using it all up to do their jobs
How are vit D & Ca related?Need vit D to absorb the Ca from your GI
Know PTH & calcitonin's fxnsPTH= ↑ blood Ca++. Calcitonin= de ("tone" it down!)
If you are worried about blood Ca++ levels, what MUST you do?You need to evaluate the IONIZED form of Ca++
What form of Ca++ is measured on blood chemistry?TOTAL is measured on chem, but if you suspect a problem you MUST measure ionized
How are the kidneys & Ca++ related? (hint: not Ca:P ratio)The kidney activates vit D!! & you need vit D to absorb Ca++ from your GI, so kidney dysfxn can lead to hypocalcemia
Which type/form of Ca++ is the BEST representation of free serum Ca++?The ionized form (not the total, bound, or complexed forms)
If I took the total Ca++ & then subtracted the albumin to get rid of the albumin bound fraction of Ca++ to determine the ionized Ca value, would I be right or wrongWRONG! DOESNT WORK LIKE THAT!
What would the CS of hypocalcemia be like?↑ excitability (lower threshold), nervousness, bh changes, facial itchiness***, muscle cramping, stiff gait, tetany, seizures (Low plasma calcium ↑ the permeability of neuronal membranes to sodium ions, causing a progressive depolarization. This ↑ the ease w/ which action potentials can be initiated)
What would the CS of hypercalcemia be like?Inhibits neurons & mm cells (↓ excitability, raises threshold)
Mineralization of tissues
D -Hypervitminosis D
R -Renal Dz
A - Addision’s
G - Granulomatous dz
O - Osteopathy
N - Neoplasia (lympsarc, anal sac, mult myel)
S - Spurious
H - Hyperparathy
I - Idiopathic - cats
T - Temp rare in cats
How does Addison’s affect Ca++ levels?Usually hypercalcemia (the A in goshdarnit), but it can also do hypo bc it does whatever it wants, it's Addison’s.
Neoplasia affects Ca++ in which way & what are the 3 most common tumors to affect Ca++ levels? (Note the #1 most common)Tumors can cz ELEVATED levels of Ca++! The most common is LYMPHOSARCOMA!! Also anal sac adenocarcinoma & multiple myeloma
Renal dz
PPancreatitis (imbalance/nutritional) OR Phosphorus (addition/enemas)
Ethylene Glycol,
Which is the stronger/more influential hormone.. PTH or calcitonin?PTH is much more powerful & will overpower any calcitonin released
If Ca++ is high & PTH is high, what is going on?1° hyperparathyroidism
If Ca++ is high & PTH is low, what is going on?Hypercalcemia of malignancy
If Ca++ is low & PTH is low, what is going on?1° hypoparathyroidism
If Ca++ is low & PTH is high, what is going on?2° hyperparathyroidism (usually nutritional or renal)
How much of the kidney is damaged in order for there to be elevated levels of Phosphorus?85%
Which age group has naturally higher levels of phosphorus & why?Puppies! Kittens! Babies! Bc phos. Is essential for growth (you need ATP ← P for phosphorus)
What affect does hypoparathyroidism have on phosphorus? Hyperparathyroidism?Hypo leads to an elevation
Hyper ↓ phosphorus (parathormone will make you pee out P to maintain Ca, So, more PTH, less P)
What does hemolysis do to phosphorus levels?↑ bc there is P in the cell which leaks out when cells rupture, artificially raising it.
Principal intracellular cation is?K+
Which ion is important in the regulation of diabetic ketoacidosis?POTASSIUM! Bc of the H+/K+ exchange mech.
Will acidosis ↑ or ↓ K?↑ bc the H+ gets pushed into the cell, so the K+ comes out into the blood & that raises blood K levels
How does hypoadrenocortisism affect K+ levels?ELEVATES!! A reduction in secretion of aldosterone, the principal mineralocorticoid, results in marked alterations of serum levels of potassium, sodium & chloride. Potassium excretion by the kidneys is reduced & results in a progressive ↑ in serum potassium levels
Principal extracellular cation?Sodium!
Principal extracellular anion?Chloride
How does chloride behave around sodium? Bicarb?Cl FOLLOWS Na, but acts inversely to bicarb
If you had a hypochloremia, would you have an acidosis or an alkalosis?Cl moves opposite of Bicarb, so lots of Cl means little bicarb, means ACIDOSIS!
Mg is where in the body?Intracellular fluid
Which ion can compete w/ Ca++ & the neuromuscular junction?Mg++
What is the main purpose of Mg?It is a COFACTOR for many bio fxns (phosphorylations, Na+/K+ ATPase, reqd for PTH secretion)
If you lose Mg++, what happens to Ca++?lose Mg → HYPOCa++
What are the CS of HYPOmagnesia?Alters depol of NMJ → mm fasciculations & tetany, seizures & coma, ↓ resting membrane potential of cardiomyocytes → arrhythmias
What are the CS of HYPERmagnesia?Neuronal depression, ataxia, hypersalivation, weakness, hypotension, loss of deep tendon reflexes (Potassium channel efflux is inhibited by magnesium)
What is anion gap?Measured cations minus the measured anions.... so (Na+ + K+)-(Cl-+ HCO3-)
What are 2 reasons there would be an ↑ anion gap? & examples of the 2 reasons?(1) Metabolic (organic) acidosis (Lactic, ketotic, uremic acidosis, or massive tissue injury)
(2) Toxins (Ethylene glycol, methanol, metaldehyde (snail bait) )
Why would there be a ↓ anion gap?This is due to a ↑ in unmeasured anions, which happens in hypoalbuminemia ((usually theyd be bound to the albumin, but it's not there so they become part of the free population)
Which enzyme is tissue specific to the muscles?Creatine kinase
What are some reasons why there would be an ↑ in creatine kinase?Myopathy, trauma & the later stages of hypothyroidism
************** WHAT ARE THE LIVER FXN SERUM TESTS?C-BAG!! C= cholesterol, B= BUN, A= albumin, G= glucose
Why would you have ↓ cholesterol?LIVER INSUFFICIENCY! Which means it can be used as a liver fxn test!!!
What did she emphasize about amylase & lipase? (When are they sig, when are they not sig)Elevations may be sig, but they are not sensitive NOR specific & have a short t1/2. Could indicate exocrine pancreas Dz, or renal dz


Question Answer
Which comes 1st in kidney damage-azotemia, or an isosthenuric USG?THE USG IS FIRST. ALWAYS GET THE USG FROM URINE, BLOOD AZOTEMIA VALUES ARE NOT USEFUL ALONE
If the urine is red/brown, what 3 things might it be?Hematuria, Hburia, myoglobinuria
What are the values for hyposthenuria?<1.008 (less conc than the plasma). Kidneys STILL WORKING bc they can dilute
What are the values for isosthenuria?1.008-1.012 (same conc as plasma) kidneys NOT WORKING....IF azotemia, bc this could just be dilute urine
What are the values for hypersthenuria for a cat? A dog?1.030 for a dog, 1.035 for a cat (horse is like 1.025 but this wasnt on the slide, she mentioned it)
If you are measuring the protein levels in a sample of urine, what must you absolutely keep in mind?THE USG! +1 protein in a super concentrated sample is less troublesome than a +1 in a very dilute sample
If you detect protein in the urine & then you get the USG, what next step could you do to figure more stuff out? What is the stuff you're trying to figure out?Do a UPC → Urine protein:creatinine ratio!!! From this you can determine the GFR!!!
What disadvantage is there to trying to detect ketones w/ the dipstick?Betahydroxybutyric acid is NOT detected by it & that is 1 of the major 3 ketones!
If there is glucose in the urine, what could it be?Well it COULD be diabetes, but glucose can also be in the urine from stress!!
When would you NORMALLY see a little bilirubin in urine?If it is a dog. ANY amount in cats is a concern.
How will a UTI affect the pH of the urine?Often czs there to be alkaline urine, bc there are urease-producing bacteria
What amount of urine SHOULD you be submitting?10mL
Explain why it's important to view the RBCs & WBCs together in a urine sample?RBC>WBC prolly trauma. WBC>RBC prolly infxn
What might be some reasons you would see an ↑ in the amount of epithelial cells (squamous, transitional, renal) in a urine sample?Inflammation, degeneration & neoplasia
Are crystals normal in urine?They can be normal. Stones are not.
What are the crystals which could be normal, or perhaps could be abnormal?Triple phosphate, Calcium oxylate, Calcium carbonate, Urate, amorphous
Which crystals are especially indicative that there is a pathology?Ammonium biurate, Tyrosine, Bilirubin, Calcium oxalate monohydrate, Cysteine
Casts will tell you about what part of the urinary tract?Localize to the kidney
What are hyaline casts made of? What do they imply?Made of mucoprotein & low numbers can be present in normal animals, especially due to exercise, dehydration & fever. However, it can also cz glom. Leakage
What are cellular casts made of? What do they imply?Man be made of any cells (RBCs if hemorrhage, WBCs if inflammation, epithelial cells if renal tubular damage)...these casts would NEVER be in normal urine
What are granular casts made of?As epithelial casts age & are modified, these form
Only evaluate bacteria if the urine sample was collected by...Cystocentesis
Why is a big reason you want to perform a sediment exam in a timely manner?Bacteria will die & be undetectable, or alter the sample