Urinalysis Flashcards
Basic structural and functional unit of kidney
Nephron
Order of urine formation
Glomerulus > pct > loop of henle > dct > collecting duct > calyx > renal pelvis
Alter urine concentration
Pct, LH, dct & collecting duct
Highly permeable to water
Ascending loop of henle
Renal blood flow
Renal artery > afferent arteriole > glomerulus > efferent arteriole > peritubular capillaries > vasa recta > renal vein
Resembles a sieve and located within the bowman’s capsule
Glomerulus
1st function to be affected in renal disease
Tubular reabsorption
Renal threshold for glucose
160 to 180 mg/dL
Major site of reabsorption of plasma subs.
PCT
Regulates water reabsorption in dct and cd
ADH/vasopressin
ADH deficiency
Diabetes insipidus
ADH excess
SIADH
Regulates sodium reabsorption
Aldosterone
2 major functions of tubular secretion
Elimination of waste products; regulation of the acid-base balance
Inability to produce an acid urine; hydrogen ions are not excreted in the urine
Renal tubular acidosis
Used to evaluate glomerular filtration
Clearance tests
Oldest clearance test
Urea
Most common clearance test
Creatinine
Gold standard in clearance test
Inulin
Used to evaluate tubular reabsorption
Concentration tests
Obsolete test(tubular reab): when px is deprived of fluid for 24hours, urine SG is then measured.
Fishberg test (SG should be >/= 1.026)
Obsolete test(renal reab): Compare day & night urine in terms in volume & sg
Mosenthal test
Commonly used test in tubular reabsorption that is influenced by the number & specific gravity of particles in solution
Specific gravity
Commonly used test in tubular reabsorption that is influenced by the number of particles in a sol’n
Osmolarity
Tests in tubular secretion & renal blood flow
PAH (p-aminohippuric acid) test, PSP (phenolsulfonphtalein) test
Urine composition
95-97% water, 3-5% solids
Type of urine: For routine and qualitive UA
Random/occasional/single
Type of urine: ideal spx for routine and preg test (HCG)
First morning
Type of urine: for evaluation of orthostatic proteinuria
First morning
Type of urine: for diabetic screening/monitoring
2-hour postprandial
Type of urine: optional with blood samples in gtt
Glucose tolerance
Type of urine: collected at specific time intervals to compare conc’n of subs in urine with its concentration in the blood (used in the diagnosis of diabetes)
Fractional specimen
Type of urine: for routine & bacterial culture
Midstream clean catch
Type of urine: for bacterial culture
Catheterized
Type of urine: bladder urine for anaerobic bacterial culture and urine cytology
Suprapubic aspiration
Type of urine: use of soft, clear plastic bag with adhesive
Pediatric spx
Type of urine: for prostatic infection
Three-glass technique
Type of urine: begin and end the collection period with an empty bladder
24-hr
True or false: 24-hr spx requires preservative
True
Type of urine: for addis count
12-hr
Type of urine: for urobilinogen
Afternoon (2-4pm)
The process that provides documentation of proper sample identification from the time of collectuion to the receipt of lab results
Chain of custody
Required urine volune in drug spx collection
30-45 mL (60 mL container capacity)
Increased changes in unpreserved urine
PH, bacteria, odor, nitrite
Least affected parameter
Protein
Normal range of urine volume (24 hrs)
600-2000 mL
Average urine volume
1 200-1 500 mL
Night : Day ratio of urine volume
1:2 to 1:3
Volume required in urinalysis
10 to 15 mL (average 12mL)
Specific gravity of DM
⬆️ SG
Specific of DI
⬇️ SG
Increased urine volume
Polyuria
Decreased urine volume
Oliguria
Complete cessation of urine flow
Anuria
Excretion of more than 500 mL of urine at night
Nocturia
Causes of oliguria
Dehydration, renal calculi or tumor
Causes of anuria
Complete obstruction (stones, carcinomas), toxic agents, dec. renal blood flow
Causes of nocturia
Pregnancy
Rough indicator of the degree of hydration
Urine color
True or false: urine color shouldn’t correlate with urine SG
False
Major pigment of urine
Urochrome
Color of urochrome
Yellow
Color of uroerythrin
Pink
Color of urobilin
Dark yellow/orange
May deposit in amorphous urates & uric acid crystals
Uroerythrin
Imparts an orange-brown color to urine that is not fresh
Urobilin
Color of urine that is correlated with strenous exercise
Dark yellow
Color of urine that is correlated with fever and burns
Amber
Color of urine that is correlated with pseudomonas infection
Green
Color of urine that is correlated with porphyrins
Portwine
Pathologic causes of urine turbidity
Rbcs, wbcs, bacteria, yeast and nonsquamous epithelial cells, abnormal crystals, lymph fluids, lipids
Normal odor of urine
Aromatic
Fruity odor
Ketones, DM
Cabbage odor
Methionine malabsorption
Rotting fish
Trimethyl aminuria
Swimming pool odor
Hawkinsinuria
Odorless
Acute tubular necrosis
Principle of glucose
Double sequential enzyme reaction
Principle of Bilirubin
Diazo reaction
Principle of ketones
Sodium nitroprusside reaction (Legal’s test)
Principle of Specific gravity
pKa change of polyelectrolyte
Principle of pH
Double indicator system
Principle of Protein
Protein error of indicator / Sorensen’s
Principle of Blood
Pseudoperoxidase of Hgb
Principle of urobilinogen
Ehrlich’s reaction
Principle of Nitrite
Greiss reaction
Principle of Leukocyte
Leukocyte Esterase
Principle of Rgt strip
Reflectance photometry
This is influenced by the number and size of particles in a solution
Specific gravity
Normal specific gravity of random urine specimen
1.003 to 1.035
SG of Isosthenuria
1.010
SG of Hyposthenuria
<1.010
SG of Hypersthenuria
> 1.010
Calibration temp of Urinometer
20degC
Rgt of Sg in rgt strip
Bromthymol blue
Important in the identification of crystals and determination of unsatisfactory specimens
pH
Normal pH of random urine specimen
4.5 to 8
pH of first morning specimen
5.0 to 8.0
pH of unpreserved specimen
9.0
Reagents in pH
Methyl red(pH4.0-6.0), Bromthymol Blue(pH6.0-9.0)
Most indicative of renal disease
PROTEIN
Protein produces what in urine when shaken?
White foam
Major serum protein found in the urine
Albumin
Pink sediment in an acidic urine
Amorphous urates
Four-sided flat plates/lemon-shaped crystal
Uric acid
Enveloped/pyrimidal shaped crystal
Calcium oxalate (dihydrate)
Oval/dumbell shaped crystal
CaOx (monohydrate)
Cigarette-butt shaped crystal
Calcium sulfate
“Thorny apples” crystals
Ammonium biurate
Coffin-lid shaped crystals
Triple phosphate
Flatplates thin prisms in rosette form
Calcium phosphate
Dumbell shaped with formation of gas
Calcium carbonate
Staircase pattern
Cholesterol
Colorless to yellow needles
Tyrosine
Concentric circles & radial striations
Leucine
clumped needles or granules with bright yellow color
Bilirubin
“Arrow head” shaped
Sulfonamide
Colorless needles
Ampicillin