Renal diagnostics Flashcards
BUN/Cr ration measure
volume status
BUN/Cr ration >20 is dehydration
Serium Creat (.5-1.2) BUN 10-20
Bun is product of protein catabolism, excreted by kidney,
can be high in dehydration, GI bleed, steroid use or tetracyclines
Stages of kid dz
stage 1: kid damage with normal or high GFR >90
stage 2: kid damage with normal or low GFR 60-89
stage 3: Moderate low GFR 30-59
stage 4: sever low GFR 15-25
Stage 5: kid failure <15 or dialysis
creatinine clearance is determined by
24 hr urine
helpful for dosing of a med
Ana
if lupus
ANCA - if granulomatotis with polyangitis
Anti GMB antibody - if Goodpastures
Hepatitis B and C serology - may cause membranous nephropathy (liver dz - check liver)
Antistreptolysin O - if poststrep GN
RF, complement levels, serum immunoelelctrophoresis
PSA prostate spec angitgen - screening for prostate CA and monitor dz
PSA is in all men but high = CA, BPH, prostatitis, after DRE!!!
UA
pH, spec gravity: reflects ability of kid to concentrate or dilute urine.
Glucose, ketones - due to dehydration.
protein - one of first signs of kid dz
Blood - calculi, glomerular damage, CA neoplasm, Acute tubular necrosis, trauma, infection
Nitrite, leukocyte esterase - infection, contamination
WBC, bilirubin, urobilinogen (liver)
Microscopic uA
RBC casts = GN, vasculitis
WBC casts = pyelonephritis, glomerular dz
Epithilial cell casts = acute tubular necrosis, GN
Crystals: stones: Uric Acie (gout), Ca phosphate or Ca oxalate = pseudogout, cysteine, Mg.
Earliest clin detectable stage of diabetic nephropathy is
microalbumin
urine eosinophils are most often seen in
interstitial nephritis; transplant rejection, pyelonephritis, prostatitis, cystitis, rapid progressive GN (he never ordered)
24 hr urine provides
a better quantitative measurement for proteinuria or GFR
Urine immunoelectrophoresis (UPEP)
Bence Jones protein - if suspect Mult myeloma MM
Bence Jones protein in UPEP is a sign of
Mult Myeloma
which stone is radiolucent (can’t see on xray)
URIC acid
huge bilat staghorn calculi are a sign of
urinary retention
Test of choice to exclude urinary tract obstruction
Renal US
- first step in pt with renal failure due to unknown
- can ID abscesses, renal cysts PCKD and masses, diverticuli, stones
Doppler US vs Renal US
Doppler checks flow
consult regarding which one to order
US - doesn’t require CONTRAST
less selective than CT in inital detection of renal mass
What is the dx test of choice for nephrolithiasis (kid stones)
NON-CONTAST CT - can detect radioluscent stones not see on KUB
CTA CT angiography
used to ID vascular problems
CT provides
more detail than US
helps distinguish between benign and malignant: eval and stage renal CA
When to do MRI
when can’t do CT becuase of contrast in kid failure (if GFR <30)
MRI CI
Gadoliunium may increase risk for nephrogenic systemic fibrosis in pts with chronic or acute renal failure
Intravenous Pyelogram IVP
Not used anymore
eval size and shape of kid, ureters, and bladde
kid stones (high sens and spec)
obstruction
requires contrast dye and not used as frequently.
REnal angio and renal biopsy
US guided biopsy
CystoUrethrogram
bladder filled with contrast
xrays taken to see contrast in bladde - can take while voiding.
Primary bladder conditions seen better than in IVP intravenous pyelogram
used to detect VESICOURETERAL REFLUX: reflux back in ureter
perforations, fistula, tumor related distortion
what is used to id VESICOURETERAL REFLUX
CystoUrethgram
Cystoscopy is used to assess bladder and ureteral CA
incontinence, to Dx interstitial cystitis, bladder turmors, stones, scarring
if find mass on DRE, do which test
TRUS trans rectal US and biopsy
