Renal Diagnostic Flashcards
(21 cards)
What is the most common measure of renal fxn?
GFR
When is GFR decreased?
renal dz, CKD, used for determining timing of renal replacement therapy
will decline w/age
how is GFR calculated?
Cockcroft-Gault, MDRD
What are GFR measurement modes?
serum creatinine, 24 urine, spot urine, estimation equations, radioiosotopic clearance
what is serum creatinine?
byproduct of brkdown of creatine phosphate in muscle- removed by kidneys via glomerular filtration
what can alter a serum creatinine lab value?
muscle mass, diet, meds
what is a 24 hour urine?
collected urine over a 24 hr cyble
clcr = urine cr X urine flow/plasma cr
may overestimate GFR
Spot Urine
marker of urinary excretion of albumin
kidney should be relatively impermeable to albmuin
**MICRO!
what is a microalbuminuria good for?
screening early kidney dz like diabetic nephropathy
what are some indications for hemodialysis?
symptomatic uremia, hyperkalemia despite adequate tx, volume overload despite adequate tx, acidosis, CrCL or EGFR <10-15 ml/min, bleeding diathesis
when you dont have time for oral meds to correct problem
why are renal US indicated?
assess size, thickness of cortex, medulla, pyramids, urinary collection system
what dz can be seen on renal US?
hydronephrosis, Polycystic dz, masses/lesions, obstructive uropathy
complications of US
poor visualization due to body habitus
CT scan of kidneys
non-contrast CT is hiighly snesitive and specific for renal stones in pts with actue flank pain
what else are CT scans used for>
solid or cystic lesion
CT scans w/ contrast
see parenchymal tissues-helpul for cysts, neoplams, vessel visualizaiton and ureters
**lung cancer can metastasize to adrenals
Renal MRI indications
cortex vs medulla –> important for glomerulonephritis, hydronephrosis, vascular occulsion, cystic lesion more visible
addition/alternaitve option for CT (renal cell carcinoma staging)
almost 100% sensitive/97% specific for Renal ARtery stenosis
what is the gold standard test for RAS?
Renal angiography- can be diagnostic and therapeutic
indications for a renall biopsy/
unexplained AKI or CKD
acute nephritic syndrom
unexplained proteinuria or hematuria, systemic dz associated w/renal dysfxn
transplant managment
Cautions for renal biopsy?
pts must be off ALL evel “bleeding humors’ w/ good BP control
post procedure hematuria
complications of renal biopsy?
1% significant bleed ristk that persists for 72 hours -inot retroperitoneal space
50% local hematoma
