Urine Analysis Flashcards
1
Q
What does the kidney eliminate?
A
excess body water
waste products of metabolism (i.e.: urea and creatinine)
foreign substance (drugs, vitamins, antibiotics)
2
Q
Other functions of kidney
A
- Retention of substances necessary for normal body function (e.g. proteins, amino acids, glucose)
- Regulation of electrolyte balance and osmotic pressures of the body fluids (e.g. sodium chloride, phosphates
3
Q
Composition of urine
A
95% water (1000 ml to 1500 ml/24 hr) 5% solute (60 g/24 hr)
4
Q
Urine solutes and equivalents
A
- Urea – most of nitrogen excreted (10g/day)
- Sodium Chloride (NaCl) – 5 to 20g/day
- Potassium – 70 mEq/day
- Sulfate – organic or inorganic, 2g/day
- Phosphates – 1 g/day
5
Q
Urine also contains small amounts of these:
A
• Sugars – pentoses
• Intermediary metabolites – oxalic acid, citric acid, pyruvate
• Free fatty acids and trace amounts of cholesterol
• Hormones – ketosteroids, estrogens, aldosterone, pituitary
gonadotropins
• Biogenic amines – catecholamines and serotonin metabolites
• Vitamins – ascorbic acid
• Porphyrins (trace amounts)
• Crystals – in concentrated urines; uric acid and phosphate
crystals (causes kidney stones)
6
Q
Formed elements seen in urine
A
− Red Blood Cell (erythrocytes)
− White Blood Cell (leukocytes)
− Renal tubular epithelial cells (of the kidney)
− Transitional epithelial cells (of the kidney)
− Squamous epithelial cells (of the urethra)
7
Q
Other substances present in urine
A
uric acid, creatinine, amino acids, ammonia and traces of proteins, glycoproteins, enzymes and purines
8
Q
ideal urine specimen for isolation of anaerobes because it bypasses normal flora of urethra
A
Suprapubic aspiration
also: clean-catch midstream specimens
9
Q
This method of specimen collection is used for specimens from children, infants and toddlers
A
collection bags
10
Q
This method of specimen collection may cause staphylococcal infections (i.e.: S.epidermidis, S. saprophyticus)
A
Indwelling catheters
11
Q
Other methods of specimen collection
A
straight catheterization
12
Q
method used in clean-catch midstream specimens
A
• Clean urethral area with a series of sponges, soap, and clean water
• Retract skin folds (labia or prepuce) before voiding
→ To avoid contamination of epithelial cells
• The first-void urine is passed into the toilet to clear the urethra
• Collect the midstream specimen
• Continue voiding
13
Q
urine needed for chemical and microscopic examination
A
voided specimen
14
Q
urine needed for protein and microscopic examination of sediments
A
concentrated specimen (preferable; i.e.: morning urine)
15
Q
Where is urine after a meal needed?
A
glucose examination
16
Q
24-hour urine is usually used for
A
quantitative analysis
also for protein
17
Q
Urine needed for bacteriologic examination
A
Voided mid-stream or catheterized specimen
18
Q
Why is first morning urine collected?
A
counts increase overnight in bladder and organisms are concentrated
19
Q
Why is fluids not forced in patients during time of collection
A
may dilute urine = false negative results, decrease count to <10^5 CFU/ml
20
Q
Method of specimen collection for asymptomatic patients
A
Collect three consecutive early morning specimens
21
Q
Important considerations in urine collection
A
- Containers (should be washed with detergent and rinsed well with water and dried; for ordinary urinalysis; sterile containers = bacteriologic examination)
- Deterioration of specimen (Should be collected in a dry, clean container; Should be examined when freshly voided)
- Storage
22
Q
Consequences of detrioration of specimen
A
- RBC and WBC destroyed by hypotonicity of urine
- Casts decompose
- Bacterial contamination
- Decreased pH
23
Q
This preserves sediments but interferes with test for protein
A
one crystal of thymol/ 10-15 ml. of urine
*one drop formalin/ 10 ml. urine also preserves sediments
24
Q
The preservation method of freezing is used for
A
bilirubin, urobilinogen, or ketones
25
Preservative tablets are used for
routine screening; preserves glucose and other constituents
26
Container used for speciment transport
sterile, wide-mouthed, screw-capped
* anaerobic transporter for suprapubic aspirate
* urine bag for pediatric patients
27
Temperature at which specimen is transported
immediately refrigerated 4C or preserved
| needed for culturing urine
28
If urine is not cultured, tubes are transported with
boric acid
glycerol
Na formate (and sometimes formalin)
*preserves bacteria without refrigeration for 24 hrs. when >10^5 CFU/ml is present in the initial urine specimen
29
General considerations during specimen transport
→ Transport urine to the lab as soon as possible after collection
→ Culture urine specimens within 2 hours after collection, or refrigerate and culture them within 8 hours whenever possible
→ Refrigerated urine specimens may be held for < 24 hrs.
30
Considerations for repeat specimen collection
• Request repeat specimen when:
→ There is no evidence of refrigeration and the specimen is more than 2 hours old
→ The collection time and method of collection have not been provided
• If an improperly collected, transported, or handled specimen cannot be replaced, document in the final report that specimen
quality may have been compromised
31
Procedure for routine urinalysis
1. Number the urine specimens and the corresponding request
2. Number the 15mL centrifuge tube corresponding to urine sample
3. Mix each specimen thoroughly and place 12 mL to corresponding
centrifuge test tube. (Note the color, turbidity and pH reactions)
4. Measure specific gravity
5. Centrifuge for 5 minutes at 1500 to 25000 rpm
• Use supernatant for testing of proteins, glucose and
reducing substances
• Use sediments for microscopic exam
32
Physical tests involved in macroscopic examination in routine urinalysis
Color, character (clarity of appearance), odor, urine volume, osmolality and specific gravity
33
normal color of urine
yellow and straw to amber-colored urine
34
Why is urine yellow?
urochrome pigment and small amounts of urobilins
35
[Abnormal findings of urine] orange urine is due to
concentrated urine
36
[Abnormal findings of urine] DEEP YELLOW URINE is due to
Riboflavin
37
[Abnormal findings of urine] amidopuride drugs causes this color of urine
bright orange
38
[Abnormal findings of urine]urobilin causes this color of drugs
orange-brown
39
[Abnormal findings of urine]greenish-orange urine is due to
bilirubin
40
[Abnormal findings of urine] smokey urine is due to
RBCs
41
[Abnormal findings of urine] What causes wine red urine?
hemoglobin pigments
42
[Abnormal findings of urine] What causes brown to black urine?
melanina
43
[Abnormal findings of urine] an almost colorless urine is due to
dilute urine
44
[Abnormal findings of urine] A reddish orange in alkaline solution is caused by
rhubarb or serra
45
[Abnormal findings of urine] a urine which is dirty green on standing is caused by
excess indicant
46
T or F: Urine is normally turbid
False, essentially clear
47
An abnormal cloudy urine is due to
* Phosphates,
* carbonates
* Prostatic fluid
* Urates, uric acid
* Mucin, mucus threads
* Leukocytes
* Calculi
* Red cells ("smoky”)
* Clumps, pus, tissue
* Bacteria, yeast
* Radiographic dye
* Spermatozoa
48
An abnormal milky urine is caused by
* Many neutrophils (pyuria)
* Lipiduria (fat)
* Opalescent
* Chyluria
* Emulsified paraffin
49
Normal odor of urine
Faint aromatic
50
Abnormal odor of urine
* Odorless (acute renal failure)
* Characteristic urine odors in ingestion of asparagus or thymol
* Urine odors associated with amino acid disorders
51
A sweaty feet odor urine is due to this amino acid disorder
Isovaleric and glutaric academia
52
This amino acid disorder causes maple syrup urine odor
Maple syrup urine disease
53
Methionine malabsorption (amino acid disorder) causes this urine odor
Cabbage, hops
54
A mousy urine is caused by this amino acid disorder
Phenylketonuria
55
Urine in Trimethylaminuria smells like
Rotting fish
56
Tyrosinemia (amino acid disorder) causes
rancid odor urine
57
What is the average daily urine volume?
1200-1500 ml (adults) *average range: 600-2000 ml; night urine: 400 ml
58
Daily urine volume for all ages
Newborn: 20-350 ml
1 year old: 360-600 ml
10 yrs old: 750-1500 ml
Adults: 750-2000 ml
59
An increase in urine volume, indicated by more than 2000 ml in 24 hours or polyuria is due to
```
− Excessive intake of water
− Increase salt intake and high protein diet
− Certain drugs with diuretic effect such as caffeine,
alcohol, and thiazides
− Intravenous saline or glucose
− Pathologic states
o Diabetes mellitus
o Diabetes insipidus
o Chronic renal failure
```
60
A decrease in urine volume is due to
− Dehydration
− Renal ischemia
− Renal disease
− Obstruction"
61
This physical test gives an indication of urinary solute concentration
Osmolality and Specific gravity
*In critical conditions, measurement of osmolality of urine and plasma is preferred over specific gravity
62
What is the normal specific gravity of urine?
1.005-1.030 (most samples: 1.010-1.025; normal adults with normal diet: 1.016-1.022/24 hours)
63
An isosthenuric urine would have this specific gravity
1.010 (hyposthenuric: <1.007)
64
normal osmolality range for urine
800-1400 mOsm/kg water (normal diet: 800)
65
These physical tests are the best indicators of hydration status
urine color and volume (dark amber urine= dehydrated; hematuria (visible/not-visible; red to pinkish color)
66
Not visible hematuria might be due to
calculi of urinary tract, UTI, trauma or malignancy
67
This physical test is helpful for determining hydration status AND KIDNEY FILTRATION FUNCTION
Specific gravity (high in dehydrated with particles like glucose in urine)
68
Turbid urine might be due to
pyuria (urine with pus); presence of protein, UTI
69
T or F: sweet or foul odor: food and medications; odor: dehydration
true
70
[Chemical methods] General methods involve
Reagent Strip Methodology (convenient; with standards)
| Confirmatory tests
71
These are properties measured by chemical methods
pH in urine
Protein in urine
Reducing substances
Glucose
72
It is reflection of the ability of the kidney to maintain normal hydrogen ion concentration in plasma and extracellular fluids
pH in urine (normal: 4.6-8.0)
73
What does a pH of 5.5 and below signify?
tubule mechanisms of acidification are intact
74
What produces acid urine?
− Diet high in meat protein and some fruits
| − Drugs: ammonium chloride, methionine, methenamine, mondelate or acid phosphatase
75
T or F: a diet high in certain fruits and vegetables produces acid urine
```
False, alkaline urine
*Other causes of alkaline urine:
− Drugs: sodium bicarbonate, potassium citrate,
acetacolamide
− Conditions involving failure to acidify urine:
o Renal tubular acidosis
o Early pyelonephritis
o Primary aldosterone secretory tumor
o Hypokalemia
```
76
How much protein is usually found in urine?
150 mg/24 hr. (1/3 albumin with remaining protein, globulin)
77
Methods used in identifying protein in urine
Reagent strip method (sensitive to albumin)
| Acid-precipitation test (detects all proteins and indicates the presence of globulins)
78
Confirmatory tests for protein in urine
```
Sulfosalicylic acid methods (Quali + semi-quanti)
Quantitative methods (more useful in diagnosing kidney d.)
```
79
How much urine and 10& sulfosalicylic acid in 50% methanol is used in sulfosalicylic acid methods?
3 ml. (+ for protein: cloudy ppt at the junction of 2 fluids)
80
This is a rough tests and at best an approximate guide to the amount of sugar
Benedict's Qualitative Test (see table of results in trans)
81
Test for acetone and acetoacetic acid
Rothera's test (a+aa = purple color with alkaline sodium nitroprusside)
82
Test for total urobilinogen and urobilin
Schlesinger's test
83
Principle for schlesinger's test
urobilinogen is oxidized with alcoholic solution of zinc acetate producing a green fluorescent complex
84
Test for BILIRUBIN
Fouchet's test
85
Test with principle of BaCl2 + Urine > Barium Sulfate (pt)
o Bilirubin is adsorbed then filtered
o F’s ferric chloride is added which produces Biliberon (greenish-blue)
Fouchet's test
86
What are the factors affecting appearance of glucose in urine?
*Methods: Reagent strip (based on specific glucose oxidase and peroxidase method)
− Blood level
− Glomerular blood flow
− Tubular reabsorption rate
− Urine flow
87
Confirmatory tests for glucose in urine
Confirmatory tests for glucose in urine
88
What is the test for other sugars?
Chromatography
89
Microscopic examination in routine urinalysis involves
Increased RBC in urine, Increased WBC in urine, Crystals, Epithelial cells, Casts, abnormal cells and other formed elements
90
Normal amount of rbcs in urine
0-2 rbcs per high power field or 3-12/microliter
91
Renal diseases associated with increased rbc in urine
```
> Glomerulonephritis >Renal vein thrombosis
> Lupus nephritis
> Trauma
> Calculus
> Hydronephrosis
> Acute infections
> Polycystic kidney
> Tuberculosis
> Acute tubular necrosis
```
92
These lower urinary tract diseases causes increased rbc in urine
> Acute and chronic infxn
> Calculus
> Tumor
>Stricture
93
Extrarenal diseases which increase rbc in urine
> Acute appendicitis
> Tumors of pelvis and rectum
> Diverculitis
> Salpingitis
94
Normal amt of WBC in urine
less than 20 leukocytes per high power field
95
Abnormalities which causes increased wbc in urine
```
→ Clumping of WBCs
→ Pyuria (Increased number of leukocytes, primarily neutrophils; seen in almost all renal diseases of the urinary tract; fevers and after strenuous activity)
→ Renal disease
> Bacterial: acute and chronic pyelonephritis
→ Calculous disease
→ Bladder tumors
→ Acute inflammatory disease
→ Chronic inflammatory disease
```
96
Bacterial renal disease in increased wbc in urine is due to
acute and chronic pyelonephritis
| > Non-bacterial: acute glomerulonephritis & nephritis
97
T or F: Crystals are usually present in freshly voided urine
false
98
These crystals are significant if found
```
− Calcium oxalate
− Uric acid
− Urates
− Cystine
− Tyrosine
− Leucine
```
99
T or F: phosphates, calcium carbonate and ammonium urate crystals are found in alkaline urine
TRUE
100
These conditions lead to INCREASE IN RENAL TUBULAR EPITHELIAL CELLS
```
→ Malignant nephrosclerosis
→ Acute glomerulonephritis
→ Acute tubular necrosis
→ Papilitis
→ Acute renal allograft rejection urates (gout)
```
101
What would an increase in transitional epithelial cells suggest?
transitional cell carcinoma of pelvis or ballder
102
What would an increase in SQUAMOUS epithelial cells suggest?
little diagnostic significance
103
These are translucent, colorless gels from protein in the tubules or nephrons
casts
104
Why are they called casts?
When proteins are concentrated in the tubules, and the person does not urinate, then the proteins would harden, and would have the shape of the tubule when excreted.
105
Different classifications of casts
→ Matrix (Hyaline and Waxy cast)
→ Inclusions (Granules, fat globules or fatty casts, hemosiderin granules, crystals, melanin granules)
→ Pigments (Hemoglobin, myoglobin, bilirubin, drugs)
→ Cells (erythrocytes and RBC elements, leukocytes, renal tubular EC, mixed cells, bacterial)
106
[Matrix class of cast] A hyaline cast is observed in
```
− Acute glomerulonephritis
− Malignant hypertension
− Chronic renal disease
− Congestive heart failure
− Diabetic nephropathy
```
107
T or F: A waxy cast (matrix) is found in localized nephron obstruction and oliguria
True
108
This inclusion almost always indicate significant renal disease
Granules (seen in pyelonephritis, viral disease, chronic lead intoxication)
109
This inclusion is commonly seen in heavy PROTEINURIA; a feature of nephrotic syndrome
Fat globules or fatty casts
110
T or F: Melanin granules are found in tubular damage
false, crystals
111
Pigments and where they are seen
Hemoglobin: tubular bleeding
Myoglobin: muscle damage
bilirubin: obstructive jaundice
112
Abnormal cells and other formed elements found in microscopic examination in routine urinalysis
* Tumor cells
* Viral inclusion cells
* Platelets
* Bacteria, fungi, parasites
* Contaminants
* Artifacts (Cotton, hair and other fibers, granules of starch, oil droplets)
