Urinalysis - More than you ever wanted to know about pee. No, seriously. Flashcards
Urine needs to be looked at within what period of time?
1 hour
What are 3 methods for urine collection?
- midstream clean catch
- catheterization
- suprapubic bladder aspiration
What’s one thing that indicates you did NOT get a clean catch?
squamous cells present in urine
What should be the timing/specifics for a urine collection for:
screening, evaluation for infection
random midstream clean catch
What should be the timing/specifics for a urine collection for:
pregnancy
first morning urine
What should be the timing/specifics for a urine collection for:
glucose testing/DM monitoring
2 hr post-prandial
What should be the timing/specifics for a urine collection for:
gestational diabetes
glucose tolerance test + blood samples
What should be the timing/specifics for a urine collection for:
protein
24 hr collection
What should be the timing/specifics for a urine collection for:
bacterial culture
catheterization
What should be the timing/specifics for a urine collection for:
prostatic infection
three-glass collection
What should be the timing/specifics for a urine collection for:
bladder urine for bacterial culture
suprapubic aspiration
orange urine
pyridium
green urine
pseudomonas
pink/red
RBCs, hemoglobin, myoglobin
Normal urine pH
Average urine pH
Normal: 4.5 - 8.0
Average: 5.0 - 6.0
What happens to the pH of urine as it stands around on your lab counter?
becomes more alkaline
What is the significance of a urine pH of 9?
Urine never gets to pH of 9. Means you need to re-do the test.
Acidic urine or alkaline urine?
UTI with E. coli
acidic
Acidic urine or alkaline urine?
starvation, DKA
acidic
Acidic urine or alkaline urine?
Proteus or Pseudomonas
alkalotic
Acidic urine or alkaline urine?
CKD
alkalotic
Range of values of specific gravity
1.005 - 1.030
specific gravity is usually (directly, inversely) related to amount of urine produced
inversely
low urine volume, high specific gravity
high urine volume, low specific gravity
Dilute urine has a (high, low) specific gravity
low
High or low specific gravity?
diabetes insipidus
low
High or low specific gravity?
DM
high
High or low specific gravity?
CHF
high
What biochemical marker is used to monitor DM?
ketones
What biochemical marker could be used in hemolytic anemia?
urobilinogen - increased
What biochemical marker would be decreased if bile ducts are obstructed?
urobilinogen - decreased
What is the main cause of glycosuria?
DM
What protein is checked for in a standard urinalysis?
albumin
What level of protein in the urine has a 90% sensitivity for significant renal injury?
3+ / 300 mg/dL
Proteinuria > 2000mg/24hrs usually indicates what?
glomerular problem
Proteinuria > 3500mg/24 hrs usually indicates what?
nephrotic syndrome
What is the difference between hemoglobinuria and hematuria?
Hemoglobinuria: when conditions outside the urinary tract results in extensive destruction of erythrocytes -> hemoglobin is filtered through glomerulus
Hematuria: whole RBCs
What if urine is cherry red but no RBCs are found in urine?
myoglobinuria
What is the usefulness of leukocyte esterase?
It is useful if tested in conjunction with nitrites - if both leukocyte esterase and nitrites are present, highly sensitive and specific for UTI
What is the downside to nitrites being useful in diagnosing UTI?
Bacteria need time to produce the nitrites - urine needs to sit in the bladder for a few hours….but if you have a UTI you probably have urinary frequency!
What if you see DYSMORPHIC RBCs?
glomerular problem!
What is this and what does it signify?
Red cell casts.
Usually means glomerulus involvement.
CURRENT 2014
What is this and what does it signify?
Renal tubular epithelial cell cast seen in renal tubular injury.
CURRENT 2014
What is this and what does it signify?
Pigmented granular cast seen in acute tubular necrosis.
CURRENT 2014
What is this and what does it signify?
Hyaline cast - notice the parallel sides, tubular shape with rounded edge, and colorless appearance. (Univ. of Delaware)
May occur normally after exercise, or may be pathologic.
What is this and what does it signify?
Red cell casts.
Usually means glomerulus involvement.
PKM lecture
What is this and what does it signify?
White cell casts
- May form in the presence of acute infectious process of the kidney such as pyelonephritis
- Inflammatory disorders such as lupus nephritis or interstitial nephritis may also cause white cell cast formation
PKM lecture
What is this and what does it signify?
Waxy cast - broad, brittle, and irregularly shaped
STASIS in the tubules…anuric or oliguric
PKM lecture
What are these and what do they signify?
Triple phosphate crystals
coffin lid shape
Can form when urine sits around on the counter
Also may indicate infection with a urea-splitting organism like Proteus (not common)
PKM lecture
What are these and what do they signify?
Oxalate crystals
double pyramid
In abundance, may mean ethylene glycol poisoning
PKM lecture
What are these and what do they signify?
Uric acid crystals
Variety of shapes and colors
Leukemia, gout, other stuff
PKM lecture
What are these and what do they signify?
Cystine crystals
hexagon shape
cystinuria
What are these and what do they signify?
Tyrosine crystals
significant liver disease
PKM lecture
