Cross Species - Chemistry, Kidneys & Pancreas Flashcards
what components from lab work should always be assessed together when interpreting kidney function?
BUN, creatinine, urinalysis with USG!!!
what do BUN & creatinine represent?
glomerular filtration rate
a decrease in GRF causes an increase in what lab values on a chemistry panel?
increased BUN & creatinine = azotemia
what are the 3 different types that an azotemia could be?
pre-renal (dehydration), renal (kidney disease), & post-renal (urinary tract obstruction)
what is uremia?
clinical presentation of azotemia - vomiting, anorexia, & weight loss
why is a USG so important when looking at an azotemic patient?
it is used to identify the type of azotemia that is present - pre-renal is usually increased, renal azotemia is isothenuria 1.008-1.012
what is BUN?
byproduct of catabolism of digested proteins that are synthesized from ammonia in the hepatocytes into urea
urea & NaCl maintain what in the kidneys?
renal medullary concentration gradient which contributes to urine concentration
how is BUN excreted? what about in ruminants?
urine, saliva, sweat, high amounts in colon in horses, up to 60% can be reabsorbed based on renal blood flow - in ruminants, it is excreted into the GIT & used for protein synthesis
if there is no concurrent increase in creatinine, what is the most common cause of an increased BUN?
upper gi bleed!!! or high protein meal
apart from a GI bleed, what other causes result in an increased BUN?
azotemia (pre, renal, or post) - early azotemia may see BUN elevation with normal creatinine otherwise creatinine will be increased
what are the top causes of a decreased BUN?
hepatic dysfunction (portovascular anomaly), dietary protein restriction, & polyuria (diabetes mellitus)
what is creatinine? how is it excreted? why is this important?
breakdown product from normal muscle catabolism that has normal production & excretion in equilibrium - excreted by the kidney, freely filtered, & not reabsorbed, so most reliable indicator of GFR
why are small elevations in creatinine significant?
increases greater than 0.2 mg/dL in 48 hours is suggestive of acute kidney injury!!!
what is the top cause of increased creatinine?
decreased GFR - 75% reduction in renal mass before an increase is seen!!!
what is the most sensitive lab marker for horses & ruminants for decreased GFR?
creatinine
why can horses have a slightly higher normal creatinine value? what about foals?
heavily muscled!! foals with placental insufficiency may have increased creatinine but it should decrease by 50% every 24 hours
what is the top cause of decreased creatinine?
decreased muscle mass particularly in small animals with muscle wasting secondary to chronic kidney disease - creatinine can underestimate renal disease severity
apart from creatinine, what are some other markers of GFR that can be measured?
SDMA in IDEXX labs - inulin clearance, but that has fallen out of favor
T/F: amylase & lipase are poor, non-specific indicators of pancreatic injury in small animals & isn’t validated in large animals
TRUE
what is the most sensitive & specific marker for pancreatic injury indicators?
pancreatic lipase immunoreactivity
when are cPLI/fPLI tests used?
used to assess for pancreatic inflammation for acute or chronic pancreatitis
what does trypsin like immunoreactivity evaluate? what is it the diagnostic of choice for?
evaluates pancreatic function but NOT inflammation - test of choice for diagnosing EPI
