Physical Examination of Urine | from Strasinger (6th ed.) Flashcards
1
Q
What are included in the physical examination of urine?
A
Determination of urine:
1) Color
2) Clarity
3) Specific gravity
2
Q
What are the basis of many medical decisions by early physicians?
A
Urine’s:
1) Color
2) Clarity
3
Q
As of today, the observation of urine’s color and clarity provides preliminary info concerning disorders such as?
A
1) Glomerular bleeding
2) Liver disease
3) Inborn errors of metabolism
4) Urinary tract infection (UTI)
4
Q
Measurement of the urine’s SG aid in what?
A
It aids in the evaluation of renal tubular fxn
5
Q
The results of the physical examination of UA can also be used to what?
A
It can also be used to confirm / to explain findings in the chemical and microscopic areas of UA
6
Q
True or False
The color of urine varies from almost colorless to black
A
True
7
Q
Variations in the color of urine may be due to what?
A
May be due to:
1) Normal metabolic fxns
2) Physical activity
3) Ingested materials
4) Pathologic conditions
8
Q
What is often the reason why a pt seeks medical advice?
A
Due to a noticeable change in the pt’s urine
9
Q
In terms of the urine’s color, what is the responsibility of the lab?
A
To determine whether the color change is normal / pathologic
10
Q
Answer the ff questions regarding the given color (of urine):
1) What is/are the cause/s of the color of the urine?
2) What is/are the clinical / laboratory correlations based on the color of the urine?
Given color: Colorless
A
1) Recent fluid consumption
2) Commonly observed w/ random sxs
11
Q
Answer the ff questions regarding the given color (of urine):
1) What is/are the cause/s of the color of the urine?
2) What is/are the clinical / laboratory correlations based on the color of the urine?
Given color: Pale yellow
A
1) Polyuria or diabetes insipidus (DI)
1. 1) Diabetes mellitus (DM)
1. 2) Dilute random sx
2) Increased 24-hr volume and low SG
2. 1) Elevated SG and (+) glucose test result
2. 2) Recent fluid consumption
12
Q
Answer the ff questions regarding the given color (of urine):
1) What is/are the cause/s of the color of the urine?
2) What is/are the clinical / laboratory correlations based on the color of the urine?
Given color: Dark yellow
A
1) Concentrated sx
1. 1) B complex vitamins
1. 2) Dehydration
1. 3) Bilirubin
1. 4) Acriflavine
1. 5) Nitrofurantoin
2) May be normal after strenuous exercise or in first morning sx
2. 2) Fever or burns
2. 3) Yellow foam when shaken and (+) chemical test results for bilirubin
2. 4) (-) bile test results and possible green fluorescence
2. 5) Antibiotic administered for UTIs
13
Q
Answer the ff questions regarding the given color (of urine):
1) What is/are the cause/s of the color of the urine?
2) What is/are the clinical / laboratory correlations based on the color of the urine?
Given color: Orange yellow
A
1) Phenazopyridine (Pyridium)
1. 1) Phenindione
2) Drug commonly administered for UTIs
2. 1) Anticoagulant, orange in alkaline urine, and colorless in acid urine
14
Q
Answer the ff questions regarding the given color (of urine):
1) What is/are the cause/s of the color of the urine?
2) What is/are the clinical / laboratory correlations based on the color of the urine?
Given color: Yellow green
A
1) Bilirubin oxidized to biliverdin
2) Colored foam in acidic urine and false-(-) chemical test results for bilirubin
15
Q
Answer the ff questions regarding the given color (of urine):
1) What is/are the cause/s of the color of the urine?
2) What is/are the clinical / laboratory correlations based on the color of the urine?
Given color: Green
A
1) Pseudomonas infection
2) (+) urine culture
16
Q
Answer the ff questions regarding the given color (of urine):
1) What is/are the cause/s of the color of the urine?
2) What is/are the clinical / laboratory correlations based on the color of the urine?
Given color: Blue-green
A
1) Amitriptyline
1. 1) Methocarbamol (Robaxin)
1. 2) Clorets
1. 3) Indican
1. 4) Methylene blue
1. 5) Phenol
2) Antidepressant
2. 1) Muscle relaxant, may be green-brown
2. 2) None
2. 3) Bacterial infections and intestinal disorders
2. 4) Fistulas
2. 5) When oxidized
17
Q
Answer the ff questions regarding the given color (of urine):
1) What is/are the cause/s of the color of the urine?
2) What is/are the clinical / laboratory correlations based on the color of the urine?
Given color: Pink
A
1) RBCs
2) Cloudy urine w/ (+) chemical test results for blood and RBCs visible microscopically
18
Q
Answer the ff questions regarding the given color (of urine):
1) What is/are the cause/s of the color of the urine?
2) What is/are the clinical / laboratory correlations based on the color of the urine?
Given color: Red
A
1) Hgb
1. 1) Myoglobin
1. 2) Beets
1. 3) Rifampin
1. 4) Menstrual contamination
2) Clear urine w/ (+) chemical test results for blood; intravascular hemolysis
2. 1) Clear urine w/ (+) chemical test results for blood; muscle damage
2. 2) Alkaline urine of genetically susceptible persons
2. 3) TB medication
2. 4) Cloudy sx w/ RBCs, mucus, and clots
19
Q
Answer the ff questions regarding the given color (of urine):
1) What is/are the cause/s of the color of the urine?
2) What is/are the clinical / laboratory correlations based on the color of the urine?
Given color: Port wine
A
1) Porphyrins
2) (-) test for blood, may require additional testing
20
Q
Answer the ff questions regarding the given color (of urine):
1) What is/are the cause/s of the color of the urine?
2) What is/are the clinical / laboratory correlations based on the color of the urine?
Given color: Red-brown
A
1) RBCs oxidized to methemoglobin
1. 1) Myoglobin
2) Seen in acidic urine after standing; (+) chemical test result for blood
21
Q
Answer the ff questions regarding the given color (of urine):
1) What is/are the cause/s of the color of the urine?
2) What is/are the clinical / laboratory correlations based on the color of the urine?
Given color: Brown
A
1) Homogentisic acid (alkaptonuria)
2) Seen in alkaline urine after standing; sp tests are available
22
Q
Answer the ff questions regarding the given color (of urine):
1) What is/are the cause/s of the color of the urine?
2) What is/are the clinical / laboratory correlations based on the color of the urine?
Given color: Black
A
1) Malignant melanoma
1. 1) Melanin or melanogen
1. 2) Phenol derivatives
1. 3) Argyrol (antiseptic)
1. 4) Methyldopa or levodopa
1. 5) Metronidazole (Flagyl)
2) Urine darkens on standing and reacts w/ nitroprusside and ferric chloride
2. 2) Interfere w/ copper reduction tests
2. 3) Color disappears w/ ferric chloride
2. 4) Antihypertensive
2. 5) Darkens on standing, intestinal and vaginal infections
23
Q
True or False
The terminology used to describe the color of normal urine may differ slightly among labs but should be consistent within each lab
A
True
24
Q
What are the common descriptions of normal color of urine?
A
1) Pale yellow
2) Yellow
3) Dark yellow
25
What is the proper way of examining the color of pt's urine?
The sx should be examined under a good light source, looking down through the container against a white bg
26
What pigment is the cause of the yellow color of the urine?
Urochrome
27
Who coined the name urochrome?
Thudichum
28
When did Thudichum coined the name urochrome?
1864
29
What is urochrome?
It is a product of endogenous metabolism
30
What is the characteristic of the production of urochrome if the body is in normal condition?
Urochrome is produced at a constant rate under normal conditions of the body
31
The actual amt of urochrome produced is dependent on what?
It is dependent on the body's metabolic state
32
At what states / conditions does increased amts of urochrome are produced?
In thyroid conditions and fasting states
33
Does urochrome also increase in urine w/c stands at room temp?
Yes
34
True or False
Because urochrome is excreted at a constant rate, the intensity of the yellow color in a fresh urine sx can give a rough estimate of urine conc
True
35
What is the color of a dilute urine?
Pale yellow
36
What is the color of a concentrated sx?
Dark yellow
37
True or False
Owing to variations in the body's state of hydration, the differences in the yellow color of urine can be normal
True
38
Aside from urochrome, what are the other 2 additional pigments?
1) Uroerythrin
| 2) Urobilin
39
True or False
Both uroerythrin and urobilin are present in much bigger quantities in the urine
False, because both uroerythrin and urobilin are present in much smaller quantities in the urine
40
True or False
Both uroerythrin and urobilin contribute little to the color of normal, fresh urine
True
41
What is the characteristic of uroerythrin in terms of color?
It is a pink pigment
42
At what type of sxs is uroerythrin most evident?
It is most evident in sxs that have been refrigerated
43
What will happen (/ what will be the result) if the urine sx is refrigerated?
The amorphous urates will precipitate
44
What is the action of uroerythrin to refrigerated sxs?
Uroerythrin attaches to the urates, producing a pink color to the sediment
45
What is urobilin?
It is an oxidation product of the normal urinary constituent urobilinogen
46
What is the action of urobilin?
It imparts an orange-brown color to urine that is not fresh
47
True or False
Certain abnormal colors of urine are seen more frequently and have a greater clinical significance than do others
True
48
What are abnormal urine colors?
1) Dark yellow / amber / orange
2) Red / pink / brown
3) Brown / black
4) Blue / green
49
Does dark yellow or amber urine may always signify a normal concentrated urine?
No, these abnormal colors of urine may not always signify a normal concentrated urine
50
What can be the cause of dark yellow or amber urine?
It can be caused by the presence of bilirubin
51
Is bilirubin an abnormal or normal pigment?
It is an abnormal pigment
52
How to detect bilirubin if it is present in the urine sx?
It will be detected during the chemical examination of urine
53
When should the presence of bilirubin be suspected?
Its presence should be suspected if yellow foam appears when the sx is shaken
54
What is the characteristic of a normal urine when shaken?
It produces only a small amt of rapidly disappearing foam
55
What is the indication if there is a large amt of white foam in the pt's urine?
It indicates that there is an increased conc of protein
56
A urine sx that contains bilirubin may also contain what virus?
Hepatitis virus
57
What is needed to be done if the pt's urine (w/c contains bilirubin) also contains hepatitis virus?
Std precautions should be followed
58
What is the color of the pt's urine if there is a photo-oxidation of large amts of excreted urobilinogen to urobilin
Yellow-orange urine
59
Is yellow foam present in a pt's urine w/c has photo-oxidation of large amts of excreted urobilinogen to urobilin when the sx is shaken?
No
60
What is the color of the urine imparted by the photo-oxidation of bilirubin and what is the cause of the presence of this color?
Yellow-green color due to the presence of biliverdin
61
What is the color of pt's urine that is frequently encountered in the lab?
Yellow-orange sx
62
What are the causes of yellow-orange sx?
Administration of:
1) Phenazopyridine
2) Or azo-gantrisin compounds
63
To whom are phenazopyridine or azo-gantrisin compounds administered?
To pts who have UTIs
64
What is the brand name of phenazopyridine?
Pyridium
65
What are the actions of the thick orange pigment?
1) It obscures the natural color of the sx
| 2) It also interferes w/ chemical tests that are based on color rxns
66
Is it impt to recognize the presence of phenazopyridine in a sx?
Yes
67
Why is it impt to recognize phenazopyridine in a sx?
For the labs to use an alternative testing procedures
68
What is the action of sxs containing phenazopyridine when shaken?
Sxs containing phenazopyridine produces a yellow foam when shaken
69
What is the issue to the yellow foam produced when the pt's urine (w/c contains phenazopyridine) is shaken?
The yellow foam produced could be mistaken for bilirubin
70
What is 1 of the most common causes of abnormal urine color?
Presence of blood
71
What is the usual color that blood produces in urine?
Red
72
What is the characteristic of red color (that is the usual color that blood produces in urine)?
It may range from pink to brown
73
The range of red color in the pt's urine (w/c is the usual color that blood produces in urine) depends on what?
It depends on:
1) Amt of blood
2) pH of the urine
3) Length of contact
74
What is the color of the urine produced if RBCs remain in acidic urine for several hrs?
Brown
75
What is the cause of the production of brown urine (if RBCs remain in an acidic urine for several hrs)?
Oxidataion of hgb to methemoglobin
76
A fresh brown urine containing blood may also indicate what condition?
Glomerular bleeding
77
What is the cause of glomerular bleeding (in a fresh brown urine)?
Conversion of hgb to methgb
78
Aside from RBCs, what are the other 2 substances that produce a red urine and result in a (+) chemical test for blood?
1) Hgb
| 2) Myoglobin
79
What is the flow of differentiation of red urine testing chemically (+) for blood?
Red urine -> clear; cloudy
- > clear -> hgburia -> red plasma
- > clear -> myoglobinuria -> clear plasma
-> cloudy -> RBCs present (hematuria)
80
What are the characteristics of the pt's urine if RBCs are present?
The pt's urine are:
1) Red
2) Cloudy
81
What are the characteristics of the pt's urine if hgb or myoglobin is present?
The pt's urine are:
1) Red
2) Clear
82
How to distinguish between hemoglobinuria and myoglobinuria?
Via examining the pt's plasma
83
What is the cause of hemoglobinuria?
In vivo breakdown of RBCs
84
What is the characteristic of the pt's plasma if hemoglobinuria is present?
The pt's plasma is color red
85
What is the cause of the production of myoglobin?
Breakdown of skeletal muscle
86
What is the difference between myoglobin and hgb?
Myoglobin is more rapidly cleared from the plasma than is hgb
87
Since myoglobin is more rapidly cleared from the plasma than hgb, does myoglobin affect the color of the plasma?
No
88
What is the characteristic of a fresh urine containing myoglobin?
It frequently exhibits a more reddish-brown color than urine containing hgb
89
True or False
The possibility of hgburia being produced from the in vitro lysis of RBCs should not be considered because the only cause of hgburia is in vivo lysis of RBCs
False, because the possibility of hgburia being produced from the in vitro lysis of RBCs must also be considered
90
What is the characteristic if the urine sx contains porphyrins?
It may also appear red
91
What is the cause of urine sxs (containing porphyrins) appearing red?
Oxidation of porphobilinogen to porphyrins
92
What is the color often referred for urine sxs (containing porphyrins) being color red?
They are often referred to as having the color of port wine
93
What are the nonpathogenic causes of red urine?
1) Menstrual contamination
2) Ingestion of highly pigmented foods
3) Medications
a. Rifampin
b. Phenolphthalein
c. Phenindione
d. Phenothiazines
94
What is the color of the urine (specifically alkaline urine) of genetically susceptible pts if they eat fresh beets?
Red color
95
What is the color of the urine (specifically acidic urine) if pts ingest black berries?
Red color
96
What is recommended to be done to urine sxs that turn brown / black on standing and have (-) chemical test results for blood?
Additional testing
97
What are the components that urine sxs (that turn brown / black on standing and have [-] chemical test results for blood) may contain?
1) Melanin
| 2) Or homogentisic acid
98
What is melanin?
It is the oxidation product of the colorless pigment, w/c is melanogen
99
When is melanin produced in excess?
When a malignant melanoma is present
100
What is homogentisic acid?
It is a metabolite of phenylalanine
101
What is the action of homogentisic acid to alkaline urine from persons w/ the inborn-error of metabolism called alkaptonuria?
It imparts a black color
102
What are the medications producing brown / black urines?
1) Levodopa
2) Methyldopa
3) Phenol derivatives
4) Metronidazole (Flagyl)
103
What are the pathogenic causes of blue / green urine?
These are limited to bacterial infections including:
1) UTI by Pseudomonas spp
2) Intestinal tract infections (resulting in increased urinary indican)
104
Can ingestion of breath deodorizers such as Clorets result in a green urine?
Yes
105
What are the medications that may cause blue urine?
1) Methocarbamol (Robaxin)
2) Methylene blue
3) Amitriptyline (Elavil)
106
What can be done w/c frequently reveals abnormally colored urine (in connection to blue / green colored urine)?
Observation of sx collection bags from hospitalized pts
107
What may the abnormal color of urine (as observed in the sx collection bags from hospitalized pts) signify?
It may signify either:
1) A pathologic condition w/c requires the urine to stand for a period of time before color development
2) Presence of medications
108
True or False
Phenol derivatives found in certain intravenous medications does not produce green urine on oxidation
False, because phenol derivatives found in certain intravenous medications produce green urine on oxidation
109
Can a purple staining may occur in catheter bags?
Yes
110
What are the causes of purple staining in catheter bags of pts?
1) Indican (w/c is present in the pt's urine)
| 2) Bacterial infection (w/c is frequently caused by Klebsiella or Providencia spp)
111
What is clarity?
It is the general term that refers to the transparency or turbidity of a urine sx
112
How is clarity determined in routine UA?
It is determined in the same manner that ancient physicians used w/c is via visually examining the mixed sx while holding it in front of a light source
113
Where should the sx be placed when examining for its clarity?
It should be placed in a clear container
114
True or False
Color should be routinely determined 1st prior to determination of clarity
False, because both color and clarity are routinely determined at the same time
115
What are the common terminologies used to report urine's clarity?
1) Clear
2) Hazy
3) Cloudy
4) Turbid
5) Milky
116
True or False
The terminology (when it comes to clarity) should be consistent within a lab
True
117
What is the term (/ explanation) for the given clarity?
Given clarity: Clear
No visible particulates, transparent
118
What is the term (/ explanation) for the given clarity?
Given clarity: Hazy
Few particulates, print easily seen through urine
119
What is the term (/ explanation) for the given clarity?
Given clarity: Cloudy
Many particulates, print blurred through urine
120
What is the term (/ explanation) for the given clarity?
Given clarity: Turbid
Print cannot be seen through urine
121
What is the term (/ explanation) for the given clarity?
Given clarity: Milky
May precipitate or be clotted
122
What is the urine color and clarity procedure?
1) Evaluate an adequate volume of sx
2) Use a well-mixed sx
3) View the urine through a clear container
4) View the urine against a white bg using adequate room lighting
5) Maintain adequate room lighting
6) Evaluate a consistent volume of urine
6. 1) Determine the urine color
6. 2) Describe the urine clarity
123
What is the characteristic of a freshly voided normal urine?
It is usually clear
124
What type of urine sx (freshly voided normal urine) is usually clear?
Midstream clean-catch sx
125
Precipitation of amorphous phosphates and carbonates may cause what?
It may cause a white cloudiness
126
The presence of squamous epithelial cells and mucus in sxs from women can result in what?
It can result in a hazy but normal urine
127
Sxs that are allowed to stand or are refrigerated also may develop what?
It may also develop turbidity that is nonpathologic
128
Improper preservation of a sx results in what?
Bacterial growth
129
What is the action of bacterial growth (being present in sxs)?
It increases sx turbidity (but is not representative of the actual sx)
130
Refrigerated sxs frequently develop what?
These frequently develop a thick turbidity
131
What are the causes of development of a thick turbidity in refrigerated sxs?
Precipitation of amorphous phosphates, carbonates, and urates
132
What is the action of amorphous phosphates and carbonates?
These produces a white ppt
133
At what type of urine sx does amorphous phosphates and carbonates produce a white ppt?
In urine w/ an alkaline pH
134
What is the action of amorphous urates?
It produce a ppt
135
At what type of urine sx does amorphous urates produce a ppt?
In acidic urine
136
What is the characteristic of the ppt produced by amorphous urates (in acidic urine)?
It resembles pink brick dust
137
Why does the ppt produced by amorphous urates resemble pink brick dust?
Due to the presence of uroerythrin
138
What are the nonpathologic causes of urine turbidity?
1) Squamous epithelial cells (in sxs from female pts)
2) Mucus (in sxs from female pts)
3) Amorphous phosphates, carbonates, and urates
4) Semen, spermatozoa
5) Fecal contamination
6) Radiographic contrast media
7) Talcum powder
8) Vaginal creams
139
What are the most commonly encountered pathologic causes of turbidity in a fresh sx?
1) RBCs
2) WBCs
3) Bacteria (cause by infection or a systemic organ disorder)
140
What are the less frequently encountered causes of pathologic turbidity?
1) Abnormal amts of nonsquamous epithelial cells
2) Yeast
3) Abnormal crystals
4) Lymph fluid
5) Lipids
141
What are the pathologic causes of urine turbidity?
1) RBCs
2) WBCs
3) Bacteria
4) Yeast
5) Nonsquamous epithelial cells
6) Abnormal crystals
7) Lymph fluid
8) Lipids
142
The clarity of a urine sx certainly provides a key to what results of examination in UA?
Microscopic examination results
143
Why does the clarity of a urine sx certainly provides a key to the microscopic examination results?
Because the amt of turbidity should correspond w/ the amt of material observed under the microscope
144
True or False
Clear urine is always normal
False, because clear urine is not always normal
145
With the increased sensitivity of the routine chemical tests, can most abnormalities in clear urine be detected prior to the microscopic analysis?
Yes
146
What are included in the current criteria w/c are used to determine the necessity of performing a microscopic examination on all urine sxs?
These include both clarity and chemical tests for:
1) RBCs
2) WBCs
3) Bacteria
4) Protein
147
What is 1 of the kidney's most impt fxns?
The kidney's ability to concentrate the glomerular filtrate by selectively absorbing essential chemicals and H2O from the glomerular filtrate
148
Is the evaluation of urine conc included in the routine UA?
Yes
149
How does the evaluation of urine conc in routine UA done?
Via measuring the SG of the sx
150
What is the help provided if SG is included in the routine UA?
To determine whether sx conc is adequate to ensure the accuracy of chemical tests
151
What is the SG of the plasma filtrate entering the glomerulus?
1.010
152
What is isosthenuric?
It is used to describe a urine w/ a SG of 1.010
153
What is hyposthenuric?
These are sxs w/ an SG below 1.010
154
What is hypersthenuric?
These are sxs that have a SG above 1.010
155
True or False
1 would expect urine that has been concentrated by the kidneys to be hyposthenuric, but this is not always true
False, because 1 would expect urine that has been concentrated by the kidneys to be hypersthenuric, but this is not always true
156
What may be the range of SG of normal random sxs?
Approx 1.002 - 1.035
157
The SG of normal random sxs depends on what?
It depends on the pt's amt of hydration
158
Are sxs having a measurement of SG lower than 1.002 probably urine?
No, these sxs are probably not urine
159
What is the range of SG of most random sxs?
Between 1.015 - 1.030
160
What is SG?
It is defined as the density of a solution compared w/ the density of a similar volume of distilled H2O at a similar temp
161
What is the density (/ SG) of distilled H2O?
1.000
162
Because urine is actually H2O that contains dissolved chemicals, the SG of urine is a measure of what?
It is a measure of the density of the dissolved chemicals in the sx
163
What are the factors that influences the urine's SG (as a measure of sx density)?
1) # of particles present
| 2) Size of particles present
164
In relation to the concept of the factors that affect the urine's SG, does large molecules contribute more to the reading than do the small molecules?
Yes
165
What is required to be done in relation to the concept that large molecules contribute more to the reading than do the small molecules?
This may require the need to correct for the presence of substances that are not normally seen in urine
166
What are the substances (w/c are not normally seen in urine) w/c may be required to be corrected (in relation to the principle of large molecules contributing more than small molecules in the SG of the urine)?
1) Glucose
| 2) Protein
167
Currently, what is the only method in use in routine UA that requires correcting?
Refractometer
168
What are the other 2 methods in use in routine UA?
1) Chemical rgnt strips
| 2) Osmolality
169
What are the different methods of current urine SG measurements?
1) Refractometry
2) Osmolality
3) Rgnt strip
170
What is the principle of the given method (in current urine SG measurements)?
Given method: Refractometry
Refractive index
171
What is the principle of the given method (in current urine SG measurements)?
Given method: Osmolality
Changes in colligative properties by particle number
172
What is the principle of the given method (in current urine SG measurements)?
Given method: Rgnt strip
pKa changes of a polyelectrolyte by ions present
173
What is refractometry?
It determines the conc of dissolved particles in a sx by measuring refractive index
174
What is RI?
It is a comparison of the velocity of light in air w/ the velocity of light in a solution
175
The conc of dissolved particles present in the solution determines what?
It determines the velocity and angle at w/c light passes through a solution
176
How does clinical refractometers make use of the principles of light?
Via using a prism to direct a specific (monochromatic) wavelength of daylight against a manufacturer-calibrated SG scale
177
The conc of the sx determines what?
It determines the angle at w/c light passes through the sx
178
What is the distinct advantage provided by the refractometer?
Determining the SG using a small volume of sx
179
How many drops of sx are needed (as a distinct advantage of determining the SG via the use of refractometer)?
1 / 2 drops
180
Are temp corrections necessary if refractometer is used? Why or why not?
No, because the light beam passes through a temp compensating liquid prior to being directed at the SG scale
181
The temp is compensated between what temp (in the refractometer)?
Between 15 DC - 38 DC
182
True or False
Corrections for glucose and protein (if refractometer is used) must be calculated
True
183
How are corrections for glucose and protein calculated?
These are calculated via subtracting 0.003 for each gram of protein present and 0.004 for each gram of glucose present
184
Where can the amt of protein or glucose present be determined?
These can be determined from the chemical rgnt strip tests
185
How is the refractometer used?
1) A drop of urine is placed on the prism
2) The instrument is focused at a good light source
3) The reading is taken directly from the SG scale
4) The prism and its cover should be cleaned after each sx is tested
186
What are the steps (/ complete procedure) in the use of urine SG refractometer?
1) Put 1 / 2 drops of sx on the prism
2) Close the daylight plate gently
3) The sx must spread all over the prism surface
4) Look at the scale through the eyepiece
5) Read the scale where the boundary line intercepts it
6) Wipe the sx from the prism clean w/ a tissue paper and H2O
187
How is refractometer calibrated?
It is calibrated via the use of distilled H2O that should read 1.000
188
When calibrating the refractometer, what should be done if necessary?
The instrument contains a zero setscrew to adjust the distilled H2O reading
189
How is the calibration of refractometer further checked?
It should be further checked via the use of 5% NaCl (w/c as shown in the refractometer conversion tables should read 1.022 +/- 0.001, or 9% sucrose that should read 1.034 +/- 0.001)
190
When should urine control sxs be run?
These should be run at the beginning of each shift
191
What should be done to calibration and control results?
These should always be recorded in the appropriate quality control records
192
Abnormally high results of SG (above 1.040) are seen in whom?
These are seen in pts who have recently undergone an intravenous pyelogram
193
What is the cause of abnormally high results (1.040 >) of SG?
Excretion of the injected radiographic contrast media
194
Who are the pts who also produce urine w/ an abnormally high SG?
Pts who are receiving dextran or other high-molecular-weight intravenous fluids (plasma expanders)
195
What happens to the pt's SG once the foreign substance has been cleared from the body?
The SG returns to normal
196
How the urine conc be measured if pts receives dextran or other high MW IV fluids?
The urine conc of these pts can be measured via the use of:
1) Rgnt strip chemical test
2) Osmometry
197
Why are rgnt strip chemical test and osmometry be used in terms of measuring their urine conc (for pts who are receiving dextran or other high MW IV fluids)?
Because these pts are not affected by such high MW substances
198
SG depends on what components?
1) # of particles present in a solution
| 2) Density of these particles (w/c are present)
199
Osmolality is only affected by what?
By the # of particles present
200
What are the substances of interest when evaluating renal concentrating ability?
Small molecules
201
What are the primary molecules w/c are the substances of interest when evaluating renal conc ability?
Primarily:
1) Sodium
2) Chloride
202
What is the molecular weight of Na?
23
203
What is the MW of Cl?
35.5
204
Does urea have an importance in the evaluation of renal conc ability?
None
205
Does urea contribute more to the SG than Na and Cl molecules?
Yes
206
What is the MW of urea?
60
207
True or False
Na, Cl, and urea all contribute equally to the osmolarity of the sx
True
208
True or False
Because Na, Cl, and urea all contribute equally to the osmolarity of the sx, a more representative measure of renal concentrating ability can be obtained by measuring osmolarity
True
209
What is an osmole?
It is defined as 1 g molecular weight of a substance divided by the # of particles into w/c it dissociates
210
What is the characteristic of glucose?
It is an nonionizing substance
211
How many grams per osmole does glucose contain?
180 g per osmole
212
What is the MW of glucose?
180
213
What is the MW of NaCl?
58.5
214
How many grams per osmole is NaCl if it is completely dissociated?
29.25 g per osmole
215
Does osmolality and osmolarity differ from each other?
Yes
216
What is the content of an osmolal solution of glucose?
It has 180 g of glucose dissolved in 1 kg of solvent
217
What is the content of an osmolar solution of glucose?
It has 180 g of glucose dissolved in 1 L of solvent
218
What is the unit of measure used in the clinical lab?
Milliosmole (mOsm)
219
Why is mOsm the unit of measure used in the clinical lab?
Because it is not practical when dealing w/ body fluids to use a measurement as large as the osmole (23 g of Na per kg)
220
How to determine the osmolarity of a solution?
It can be determined by measuring a property that is mathematically related to the # of particles in the solution (colligative property) and comparing this value w/ the value obtained from the pure solvent
221
What are the changes in colligative properties caused by solute dissolved in solvent?
1) Lower freezing point
2) Higher boiling point
3) Increased osmotic pressure
4) Lower vapor pressure
222
Answer the ff questions w/ regards to the given property:
1) What is the normal pure H2O point?
2) What is the effect of 1 mole of solute?
Given property: Freezing point
1) 0 DC
| 2) Lowered 1.86 DC
223
Answer the ff questions w/ regards to the given property:
1) What is the normal pure H2O point?
2) What is the effect of 1 mole of solute?
Given property: Boiling point
1) 100 DC
| 2) Raised 0.52 DC
224
Answer the ff questions w/ regards to the given property:
1) What is the normal pure H2O point?
2) What is the effect of 1 mole of solute?
Given property: Vapor pressure
1) 2.38 mm/Hg at 25 DC
| 2) Lowered 0.3 mm/Hg at 25 DC
225
Answer the ff questions w/ regards to the given property:
1) What is the normal pure H2O point?
2) What is the effect of 1 mole of solute?
Given property: Osmotic pressure
1) 0 mm/Hg
| 2) Increased 1.7 x 10^9 mm/Hg
226
What is the solvent in urine?
H2O
227
True or False
Because H2O is the solvent in urine, the # of particles present in a sx can be determined by comparing a colligative property value of the sx w/ that of pure H2O
True
228
What is the special equipment that is required to measure osmolality in the UA?
Osmometer
229
True or False
The use of an osmometer is not an additional step in the routine UA procedure
False, because the use of an osmometer is an additional step in the routine UA procedure
230
True or False
The term "molality" is the most commonly used because the solute and the solvent are both expressed in the same units of measure
True
231
What is the meaning of A2O?
Advanced Automated Osmometer
232
What is the action of A2O?
It uses freezing point depression to measure osmolality, providing a more automated method for measuring both urine and serum osmolality
233
What is the help provided by the addition of a SG testing to UA chemical rgnt strips?
It has provided a convenient way to perform the routine UA by eliminating the need for an additional procedure
234
The rgnt strip rxn is based on what?
It is based on the change in pKa (dissociation constant) of a polyelectrolyte in an alkaline medium
235
What is the action of polyelectrolyte?
It ionizes, releasing hydrogen ions in proportion to the # of ions in the solution
236
True or False
The higher the conc of urine, the lesser hydrogen ions are released, thereby lowering the pH
False, because the higher the conc of urine, the more hydrogen ions are released, thereby lowering the pH
237
What is the indicator used on the rgnt pad (/ in the rgnt strip for SG)?
Bromthymol blue
238
What is the action of bromthymol blue on the rgnt pad (/ on the rgnt strip for SG)?
It measures the change in pH
239
What is the color change of the indicator (in the rgnt pad [in the rgnt strip for SG]) as the SG increases?
The indicator changes from blue (1.000 [alkaline]), through shades of green, to yellow (1.030 [acid])
blue (1.000 [alkaline]) -> green -> yellow (1.030 [acid])
240
What is the interval used when reading results from the rgnt strip for SG?
0.005 intervals (accompanied w/ careful comparison w/ the color chart)
241
Is urine odor a noticeable physical property?
Yes
242
Is urine odor clinically significant?
Yes, seldomly
243
Is urine odor a part of the routine UA?
No
244
What is the odor of a freshly voided urine?
Faint aromatic odor
245
What is the odor that becomes more prominent as the urine sx stand?
The odor of ammonia
246
What is the cause of the characteristic ammonia odor (when the urine sx stands)?
Breakdown of urea
247
What are the causes of unusual odors?
1) Bacterial infections (w/c causes a strong, unpleasant odor similar to ammonia)
2) Diabetic ketones (w/c produce a sweet or fruity odor)
248
What is maple syrup urine disease (MSUD)?
It is a serious metabolic defect results in urine w/ a strong odor of maple syrup
249
What are the foods (when ingested) that can cause an unusual or pungent urine odor?
1) Onions
2) Garlic
3) Asparagus
250
True or False
Studies have shown that although everyone who eats asparagus produces an odor, only certain genetically predisposed people can smell the odor
True
251
What is/are the possible cause/s of the given urine odor?
Given urine odor: Aromatic
Normal
252
What is/are the possible cause/s of the given urine odor?
Given urine odor: Foul, ammonia-like
Bacterial decomposition, UTI
253
What is/are the possible cause/s of the given urine odor?
Given urine odor: Fruity, sweet
Ketones (DM, starvation, vomiting)
254
What is/are the possible cause/s of the given urine odor?
Given urine odor: Maple syrup
MSUD
255
What is/are the possible cause/s of the given urine odor?
Given urine odor: Mousy
Phenylketonuria
256
What is/are the possible cause/s of the given urine odor?
Given urine odor: Rancid
Tyrosinemia
257
What is/are the possible cause/s of the given urine odor?
Given urine odor: Sweaty feet
Isovaleric acidemia
258
What is/are the possible cause/s of the given urine odor?
Given urine odor: Cabbage
Methionine malabsorption
259
What is/are the possible cause/s of the given urine odor?
Given urine odor: Bleach
Contamination
