urinalysis and hematuria Flashcards
1
Q
what is a urine reagent strip also known as
A
urine dipstick or urine dip
2
Q
what is a urine reagent strip used for
A
Rapid semiquantative analysis for several urine parameters such as:
RBC (heme), leukocyte esterase, nitrite, albumin, pH, specific gravity, glucose, bilirubin, urobilinogen
3
Q
what is the ideal sample for a urine reagent strip
A
“clean catch” urine
4
Q
what is normal color for urine
A
usually translucent “straw yellow”
5
Q
what could cloudy urine indicate
A
- pyuria
- bacteriuria
- diet
6
Q
what pathologies are reflected by the following colors?
red
red-orange
orange
intense yellow
green
brown
purple
A
Red - blood, beets, phenazopyridine
Red-orange - phenazopyridine, rifampin
Orange - phenazopyridine
Intense yellow - vitamin B
Green - pseudomonas, amitriptyline
Brown - Rhubarb
Purple - UTI
7
Q
what is the description of normal smell of urine
A
urinous odor
8
Q
what pathological origin could the following smells indicate:
ammonia odor
fishy/pungent
strong urine odor
fecal odor
sweet/fruity/acetone
maple syrup
musty odor
A
- “Ammonia” odor - Bladder retention, long-standing urine
- “Fishy” or “pungent” odor - UTI
- “Strong” urine odor - concentrated urine
- “Fecal” odor - bladder-intestinal fistula
- “Sweet” or “fruity” odor, “acetone” odor - DKA
- “Maple Syrup” odor - Maple Syrup Urine Disease
- “Musty” odor - PKU
9
Q
what two things may cause abnormal urine odor(this was so oddly specific)
A
- asparagus
- vitamin B6
10
Q
what is normal pH range for urine?
A
4.5-8 (usually about 5-6)
11
Q
what can caused alkaline urine
A
- bacteria such as proteus
- vegetarian diet
- low carb diet
- citrus
- metabolic disorders/errors
12
Q
what can cause acidic urine
A
- high protein diet
- cranberries
- metabolic disoders/errors
13
Q
what would a + “heme” dipstick test suggest
A
urine containing one or more of the following
- RBCs
- hemoglobin
- myoglobin
14
Q
what are possible pathological causes for + heme dipstick test
A
- kidney injury/disease
- GU tumor
- GU tract trauma/inflammation
- nephrolithiasis
- UTIs
15
Q
what could cause false positives in heme dipstick tests
A
- menstrual blood contamination
- semen in urine
- vigorous exercise
- concentrated urine
16
Q
what could cause false negatives in heme dipstick tests
A
high ascorbic acid levels in urine
17
Q
what must be used to diagnose true hematuria
A
microscopy with confirmation of presence of RBCs
18
Q
what is leukocyte esterase
A
enzyme produced by WBCs
this test indicates presence of WBCs
19
Q
what pathology is a + leukocyte esterase suggestive of
A
suggestive but NOT diagnostic of UTI
20
Q
aside from UTI, what are other common causes of + leukocyte esterase
A
- renal disease
- asymptomatic bacteriuria
21
Q
what could cause a false + leukocyte esterase
A
- contamination
22
Q
what could cause false negatives in leukocyte esterase
A
- high specific gravity
- glycosuria
- urobilinogen
- medications (rifampin, phenazopyridine)
- ascorbic acid
23
Q
what is the nitrite level in normal urine
A
0
24
Q
what produces nitries
A
gram negative bacteria
24
what could cause false positive nitrites in urne
* contamination (bacteria in sample but not in urinary tract)
25
what causes false negatives for nitrites in the urine
* non-nitrite producing organisms
* frequent urination
* dilute/acidic urine
* urobilinogen
26
what is urobilinogen
bilirubin metabolism by gut bacteria
27
What could increase urobilinogen
* hemolysis
* hepatocellular disease
28
what could decrease urobilinogen
* biliary obstruction
* altered gut flora
29
Im not really sure what this means
okay. thanks
30
what could cause false negatives and positives in bilirubin
false +: phenazopyridine
false -: ascorbic acid
31
how much glucose detected on a urine dip is suspicious for DM
any positive glucose at all.
the urine should contain such small amounts of glucose that the urine dip is negative
32
what could cause a false negative for urine glucose
* ketones
* ascorbic acid
33
what are causes of ketones in the urine
* post-exercise
* fasting
* pregnancy
* may see elevated in DM patients prior to serum ketosis occurring
34
what could cause false positives of ketones in the urine
* dehydration
* levodopa metabolites
35
what type of protein is urine protein sensitive to?
albumin only
36
what could cause false positives in urine protein? false negatives?
* False positive - WBCs, epithelial cells, bacteria
* False negative - dilute urine, lower proteinuria levels
37
what is specific urine gravity
Weight of urine compared with weight of water
gives estimate of urine concentration and osmolality
38
what is urine osmolality
measures the number of particles in the urine
39
when may urine osmolality and urine specific gravity not match up
if there are very large particles in the urine such as protein or contrast
40
what occurs during urine microscopy
* urine is centrifuged to cause sediment to precipitate
* This sediment is then resuspended in a small volume of urine and put onto a glass slide for analysis
41
what is considered positive result for red blood cells in urine microscopy
>5 RBC per HPF on a single occasion OR >3 RBC per HPF on multiple occasions
42
what are the causes of RBC in urine microscopy
glomerular damage, tumors, trauma, nephrolithiasis, infection, inflammation, nephrotoxins, AKI
If dysmorphic - likely d/t glomerular disease
if round (normal) - likely d/t urinary tract epithelial disease/damage
43
what are RBC casts
Mucoprotein with RBCs inside or stuck together
44
what are causes of RBC casts
* glomerulonephritis
* vasculitis
* low urine flow can promote formation
45
what is considered significant WBCs on urine microscopy
>5 WBCs per HPF
46
what does WBCs on urine microscopy indicate? what can cause this?
injury to the urinary tract.
- infection
- stones
- strictures
- cancer
- glomerulonephritis
- interstitial cystitis
- AKI
47
what are WBC casts
WBCs inside or stuck together by mucoprotein
48
what do WBC casts indicate? what could cause this?
indicates inflammation of the kidney.
caused by:
- acute pyelonephritis
- interstitial nephritis
- low urine output promotes formation
49
is bacteria in the urine common? why or why not?
Common in urine due to microbial flora of vagina, external genitalia
50
what urine bacteria pattern would be suspicious of infection
* Single organism = more likely to be infection
* Multiple organisms = more likely to be contamination
51
what bacterial count is suspicious of a UTI or bacteriuria
* >100,000 colony count/mL - UTI or bacteriuria
* Treat if symptomatic or high-risk for infection
52
if you see _any_ bacteria in this type of urine catch, it is significant and indicative of UTI/bacteriuria
Catheterized or suprapubic tap - any bacteria = significant
53
what could yeast in the urine microscopy indicate. what is the MC species of yeast?
* indicates Contaminant or true infection
* MC species - Candida albicans
54
when are tubular epithelial cells normal vs increased?
* Normally slough in small numbers
* Nephrotic syndrome or any tubular degeneration → increased shedding
55
if lipiduria occurs, what happens to the tubular epithelial cells
endogenous fat droplets fill these cells, creating:
“oval fat bodies,” “Maltese crosses,” or “grape clusters”
56
what are squamous epithelial cells? what do they indicate on a urine microscopy?
* Cells of skin surface or outer urethra
* Suggest urine contamination
57
what are transitional epithelial cells indicative of?
If present in high numbers, concerning for neoplasm
58
what type of casts are common and can be a normal finding
hyaline casts
59
what are granular casts? what are they a sign of?
* Cellular casts which remain in urine long enough to degenerate
* sign of renal damage
60
what are waxy casts? what do they indicate?
* Wide, bland-looking casts
* Shaped like wide, dilated nephrons - CKD
61
this is a good pic to differentiate gross vs microscopic hematuria
62
should gross hematuria or microscopic hematuria be evaluated?
Both gross and microscopic hematuria require evaluation. The upper urinary tract should be imaged, and cystoscopy should be performed if there is persistent hematuria in the absence of infection.
(i just felt like this blurb was important but didnt know how to ask about it lol)
63
what should be the initial test when evaluating for hematuria
UA
A fresh, midstream, clean-catch or catheterized urine specimen should be collected.
64
If you see positive WBC, leukocyte esterase, or nitrites what could it indicate and how would you further evaluate this patient?
indicates possible infection and may be confirmed by urine culture (if indicated) and treated appropriately
65
if you see proteinuria and RBC casts what does this indicate and what further evaluation is indicated in this patient?
indicate renal origin – labs and renal imaging along with a nephrology consult are indicated
66
what can assist in the diagnosis of a bladder neoplasm
urinary cytology and/or cystoscopy with biopsy.
67
what other tests could be used in the work up of hematuria
* serum BUN/Cr and GFR - to assess renal fxn and suitability for radiographic studies w contrast
* CBC - to evaluate for anemia and infection
* Coags if coagulopathy is suspected
68
what is the imaging modality of choice when evaluating the upper tracts for sources of hematuria?
* CT urography (choice)
* MRI is also used but is not first choice
69
what is the use of CT abdomen/pelvis with and w/o contrast in the evaluation of hematuria
may identify neoplasms of the kidney or ureter as well as benign conditions such as urolithiasis, obstructive uropathy, papillary necrosis, medullary sponge kidney, or polycystic kidney disease.
70
what is the role of US in urinary tract for hematuria
The role of US of the urinary tract for hematuria is unclear. Although it may provide adequate information for the kidney, its sensitivity in detecting ureteral disease is lower. In addition, its higher degree of operator dependence may further confound its utility.
so basically dont choose it.
71
what is IV pyelogram and when is it used
An x ray of the urinary tract using contrast medium to visualize urine and possible blockage in the urinary tract.
72
what is used to rule out pathology of the lower urinary tract?
cystoscopy
ideally performed whil patient is actively bleeding to allow better localization
(ie, lateralize to one side of the upper tracts, bladder, or urethra).
73
heres just some images of cystoscopy!
74
when should biopsy be cautioned
in patients with known coagulopathy
75
what is the treatment for hematuria
* Treatment of underlying cause
* Rule out possibility of cancer or serious underlying disease with potential for harmful long-term sequelae
76
what is the follow up protocol for hematuria
since the cause may never be found, negative evaluations (repeat evals) should be done to avoid missing malignancy.
- No set frequency for repeat evaluations
- Urinary cytology can be repeated in 3–6 months
- Cystoscopy and upper tract imaging can be repeated after a year
77
when is referral indicated in hematuria
If no infection is present, persistent/recurrent hematuria requires evaluation with urology or nephrology as appropriate
78
yay! done with another one! flip for a flashback to rhys' first christmas
