Nephrology: Diagnostic Testing Flashcards
Urinalysis
best initial tests for all renal disease after BUN/Cr
not recommended for routine screening - except pregnant
dipstick
30mg - 300 mg day - microalbuminuria
300mg - 1 gram = trace
1 gram per day, if evenly distributed all day give 1+
2 grams per day gives 2+
10 grams per day gives 4+
once you are nephrotic, it doesn’t matter how nephrotic you are
stress
any stress gives protein in urine
trace proteinuria
repeat the test
if pt on feet all day, then split the urine to make sure this isn’t orthostatic (more benign)
if persistent, then do renal biopsy
hematuria
tumor, trauma, treatments
stones, renal infections, bladder infections, tumors (bladder cancer), cyclophosphatide, glomerulonephritis
if bladder - instant RBCs
if kidney - dysmorphic RBCs (glomerulonephritis)
nitrites
bacteria eat nitrATES and convert to nitrites
gram- bacteria
not as important as white cells
white blood cells
most important thing to look for infection
3 days of bactrim
eosinophils - allergic interstitial nephritis
bacteriuria
hard to get clean catch, especially in women
bacteria is bacteria in urine with absence of white cells, doesn’t mean much
except in pregnancy in which 30% go on to pyelonephritis - routine screening is recommended
hyalin casts
protein in urine with pre-renal syndrome
these are protein accretions
this means dehydration
red-cell casts
glomerulonephritis
granular casts
dead tubule epithelial cells
eosinophil casts
allergic interstitial nephritis
absence of casts
doesn’t mean much. if you have casts of any type it is helpful, but if you don’t have casts, doesn’t mean much…. could still have a renal problem.
quantification of proteinuria
spot protein/creatinine ratio has same accuracy of 24 hour protein.
it compensates up for the variation of renal function throughout the day
