Renal Diseases Flashcards
is creatinine or BUN high molecular weight?
creatinine
what type of environment does the inner medullary tissue operate in?
hypoxic environment
why can you have false positives on dipsticks for protein?
alkaline urine: pH 8.5
what prevents crystals aggregating into uroliths in horse urine?
mucus
what is azotemia?
abnormally increased concentrations of nonprotein nitrogenous substances in blood
what do we look at in urine for renal biomarkers?
uGGT
protein:creatinine ratio
urine specific gravity
where is creatinine filtered?
in glomeruli
what does symmetric dimethylarginine correlate with?
GFR
serum creatinine
what is influence of extrarenal factors like on symmetric dimethylarginine?
low influence of extrarenal factors
what is renal failure?
inability to concentrate/dilute urine
what is structural kidney disease diagnosed with?
palpation/imaging
can/cannot precede alterations in function
what is acute kidney injury?
serum creatinine increase by 0.3 mg/dl
increase in creatinine >1.5 x baseline
oliguria <0.5 ml/kg/hr for 6 hours
what causes damage to epithelial cells?
ischemia
nephrotoxins
what is chronic kidney injury?
creatinine >2.0 mg/dl
longer than 3 months
what structural changes occur with chronic kidney disease?
glomerular basement membrane changes
expanded mesangial matrix
glomerulosclerosis
tubulointerstitial fibrosis
what does thyroidization in CKD result in?
hyaline casts
what can cause dehydration or a hypotensive event that can lead to kidney injury?
excessive sweating with exercise
colic or colitis
anaphylactic event
endotoxemic event
what are the common causes of renal disease in horses?
colic
colitis
aminoglycoside antibiotics
NSAIDs
what do aminoglycosides cause in the kidneys?
accumulate in proximal tubular epithelial cells
acute tubular necrosis in proximal tubules
how do NSAIDs cause renal damage?
inhibition of prostaglandins
exacerbate ischemia, specifically in medulla: medullary necrosis
metabolites may have direct toxicity when excreted
are COX-2 selective NSAIDs more protective of the kidneys?
no
what is the pathophysiology of acute renal failure in rhabdomyolysis?
renal vasoconstriction
toxic effect on renal tubules
cast formation
if there is no response with oliguria in 72 hours, what is the prognosis?
grave
what does furosemide do?
inhibits Na/K/2Cl transport
decreases metabolic requirements of kidneys
when is blood urea nitrogen low?
building muscle
how much of the cardiac output do the kidneys receive?
20%
what makes horse urine turbid?
calcium carbonate and oxalate crystals
what has traditionally been used as a biomarker of glomerular filtration rate?
creatinine
what does a small increase in serum creatinine indicate in early kidney disease?
large decrease in GFR
what does a large increase in serum creatinine indicate in advanced kidney disease?
smaller decrease in GFR
does structural kidney disease always produce alterations in function?
not always
can functional kidney disease occur with no structural changes?
yes
what are some pre-renal causes of azotemia?
decreased perfusion: dehydration, hypovolemic shock, cardiac failure
what are some causes of decreased GFR (renal azotemia)?
renal injury
inflammatory changes
toxic insult
infectious diseases
what can cause damage to epithelial cells and acute tubular necrosis?
ischemia
nephrotoxins
is a biopsy necessary to diagnose chronic kidney disease?
no: lab and history
can help with cause
what is high in chronic kidney disease?
calcium
azotemia
potassium
metabolic acidosis
why is hypercalcemia seen with chronic renal disease?
decreased urinary excretion
increased bone turnover (PTH)
what are some toxins that can cause kidney disease?
antibiotics: gentamicin, oxytetracycline
NSAIDs: flunixin, firocoxib, phenylbutazone
other: red maple, vitamin K3, vitamin D
what are the less common causes of renal disease?
hemorrhage
exhaustive exercise
rhabdomyolysis
is a substantial amount of AKI due to iatrogenic causes?
yes
do reagent strips differentiate between myoglobinuria, hemoglobinuria, and hematuria?
no
why does renal vasoconstriction occur with rhabdomyolysis?
damaged myocytess sequester fluid: hypovolemia
activation of renin-angiotensin system
what rate of fluids should you use if the animal is drinking?
40-80 ml/kg/day at most
20-40 ml/kg/day until creatinine normal
how can you worsen an AKI with fluids?
hypervolemia
what is a risk with mannitol?
fluid overload
overdose can induce AKI
hyperkalemia
what should you monitor for on low-dose dopamine?
tachycardia
hypertension
