which phase will removal of inciting cause NOT result in immediate return to normal renal function? how long will it take to restore fx?
During maintenance phase, will GFR return to normal if renal blood flow is restored?
no, still remains low
can a patient in maintenance phase convert from oliguria to polyuria?
yes (this would be better because you can continue fluid therapy w/polyuria)
during recovery phase, is it possible for BUN/creatine able to return to normal? what about GFR? What about specific gravity?
- possible for BUN/Crea to correct in time
- GFR may remain low
- concentrating defect may persist (low SG)
what is the definitive test for diagnosing AIRF?
- trick question, there is none
- but history + blood/urine/specific gravity helpful BEFORE starting therapy
Does AIRF patient usually have longstanding PU/PD issues? weight loss?
- no, this is an acute disease and urine output is variable
- no wt loss (acute) but often dehydrated
what is renal size in AIRF?
- normal or large
- (small in chronic)
Chronic, acute or both: uremia? what are signs of uremia?
- uremic breath, oral ulcers, tongue tip necrosis
chronic, acute or both: pale mucous membrane?
- pallor with chronic (anemia)
- pallor not usually associated with acute unless in shock (peripheral constriction)
nephrosis or nephritis: hypothermia?
- hypothermia = nephrosis
- hyperthermia = nephritis
what is potassium status in chronic v. acute?
- acute: hyperK
- chronic: hypoK
acute, chronic or both: anemia?
- (can see regenerative response w/AIRF if recent hemorrhage)
What is TP in AIRF?
- normal to elevated if dehydrated
- (later samples may appear low TP if overhydrated w/fluids)
why is lepto associated with thrombocytopenia?
vasculitis --> consumptive thrombocytopenia
What is definition of isosthenuria? Can this be used to distinguish acute from chronic disease?
- urine concentration = plasma concentration
- no, both have low SG
can proteinuria be used to distinguish acute from chronic? hematuria? glucosuria?
Does absence of casts exclude AIRF?
no, although cylindryuria is common
what crystals are seen with ethylene glycol?
Increased WBC, RBC and tubular epithelial cells in urine sediment are indicative of what? How does this differ from sediment with WBC and bacteria?
- non-specific reaction to renal injury
- WBC/bacteria more indicative of pyelonephritis (think ascending UTI)
increased BUN,Creatinine and phosphorus continues to rise with AIRF until which stage? does magnitude of these values distinguish AIRF v. CRF?
- maintenance where it reaches plateau
- No (nor does it tell if pre/post/renal)
what do you expect blood gas tests to reveal in pt with AIRF in maintenance phase?
moderate/severe metabolic acidosis (more severe than in CRF)
What ultrasound findings help distinguish acute v chronic RF: brightness, size, corticomedullary junction?
- brightness and size (acute is bright and normal/large)
- not cm-junction
Can you rule out AIRF if ultrasound findings are normal? Can you determine the cause of AIRF based on US findings?
- no (except possibly ethynol poisoning)
How can parathyroid gland help distinguish acute from chronic renal failure?
- enlarge with chronic (incr. Ca++)
- normal with acute
What are two specific infectious causes of AIRF that you can send in serum samples for?
- Borrelia (rapid progressive glomerular nephritis)
will renal biopsy distinguish acute v. chronic? can it distinguish nephritis v. nephrosis?
- can also assess for healing potential/prognosis
Most causes of AIRF are poor to grave prognosis. Which etiology of AIRF has fair to good prognosis?
lepto and bacterial pyelonephritis
Are patients with baseline azotemia during maintenance phase often successfully managed without dialysis? is hemodialysis or peritoneal dialysis more effective
- NO (80% die even with dialysis)
- hemodialysis more effective (2-3x/wk for months with AIRF)
Why do animals die with AIRF?
- metabolic acidosis
- severe azotemia (dogs worse off than cats with this)
- (also overhydration/pulmonary edema from vigorous fluids)
When treating AIRF, how much fluids should be given over 4 hour period?
volume equal to insensible needs plus volume equal to urine output for previous 4 hours
what are treatments of choice for hyperkalemia?
- insulin + glucose (or glucose alone; NEVER insulin alone)
- Ca gluconate
- if hyperK persists, must proceed to dialysis
what are some drugs commonly given to treat oliguria? how effective are they?
- furosemide, dopamine, mannitol
- futile effort to try to get kidney to produce urine
What is special about Sierra brand anti-freeze?
- it's not fatally toxic to animals (but more $$)
- can call illness but usually not fatal
what are first signs of toxicity with ethylene glycol? when do renal signs appear?
- neurologic ("drunk") within 30-12hr of ingestion
- cardiopulmonary 12-24hr (tachy-)
- renal 24-72hr (PU/PD)***usu.too late if get patient in clinic once azotemic already
What is most important cause of damage from ethylene glycol? what else is bad?
- metabolite = glycolate (by 12 hours)
- Ca oxalate crystals compressing/blocking tubules
- tubular back leak
- interstitial edema --> compressed renal blood flow
how can you test for ethylene glycol? what is time for detection post ingestion? what can cause false negatives?
- colorimetric test on whole blood or serum
- undetectable in plasma <30 or >48hr post ingestion
- false from propylene glycol, glycerol, metaldehyde (snail bate)
what are treatment options for ethylene glycol poisoning?
- ethanol dilute to 20% (will cause CNS depression)
- 4-methyl pyrazole to prevent metabolism (no depression, $$)
- (Ca gluconate for hyperkalemia; Na bicarb for acidosis if fluids don't correct it)