Unit 6 Flashcards
Urinalysis
1
Q
What is the typical urine daily volume
A
600-2000 mL
2
Q
What is the typical Urine Osmolality
A
300-900
3
Q
pH for Urine
A
4.6-8.0
4
Q
When is a post prandial specimen needed
A
To test for estimation of glucose or of urobilinogen
5
Q
What temperature should a 24 hour urine specimen be kept at
A
4-6
6
Q
What is 24 hour testing used for
A
quantitative estimation of proteins and hormones
7
Q
When urine is left at RT what occurs to it
A
-Increase of pH
-Formation of crystals
-Loss of ketone bodies (volatile)
-Decrease of glucose
-Oxidation of bilirubin to biliverdin (false = for bilirubin)
-Oxidation of urobilinogen to urobilin (false = for urobilinogen)
-Bacterial proliferation
-Disintegration of cellular elements (especially alkaline and hypotonic urine)
8
Q
What is polyuria
A
urine volume over 2000mL in 24 hours
9
Q
When is polyuria seen
A
diabetes mellitus
diabetes insipidus
chronic renal failure
diuretic therapy
10
Q
What is oliguria
A
<400mL of urine in 24 hours
11
Q
What are causes of oliguria
A
Febrile state
acute glomerulonephritis
CHF
Dehydration
12
Q
What anuria
A
<100mL of urine in 24 hours
13
Q
What are the causes of anuria
A
acute tubular necrosis
acute glomerulonephritis
complete urinary tract obstruction
14
Q
What can cause red urine
A
Hematuria
hemoglobinuria
porphyria
myoglobinuria
15
Q
What causes dark brown to black urine
A
Alkaptonuria
Melanoma
16
Q
What causes brown urine
A
hemoglobinuria
17
Q
What causes yellow-green or green urine
A
Biliverdin
18
Q
What causes orange or orange-brown urine
A
Urobilinogen
porphobilinogen
19
Q
What causes milky white urine
A
Chyluria
20
Q
What cause red or orange and fluorescence with UV light urine
A
Porphyria
21
Q
What is the reason for foamy urine
A
presence of excess proteins or bilirubin
22
Q
What is the appearance of amorphous phosphates
A
White and cloudy
*alkaline urine
23
Q
What is the appearance of amorphous urates
A
Pink and cloudy
*Acidic urine
24
Q
What is the appearance of pus cells
A
varying grades of turbidity
25
What does fruity urine signify
ketoacidosis
starvation
26
what does mousy or musty urine signify
phenylketonuria
27
what does a fishy urine signify
urinary tract infection with E coli
old standing urine
28
What does a foul smelling urine signify
UTI
29
What does a sulfurous urine signify
Cystinuria
30
What is Specific Gravity mainly related to
Urea and Sodium
31
What will make SG decrease
When temperatures rise
32
What does SG measure
Concentrating ability of kidneys and determines tubular function
33
What can SG be affected by
Proteinuria
Glycosuria
34
What are the SG Methods
Refractometer
Reagent Test Strip
Urinometer
35
What does a refractometer do
Measures the reflective index of the total soluble solids
36
How does the SG reagent strip work
Measures the concentration of ions. Depending on ionic strength, a polyelectrolyte will ionize in proportion.
37
What is the color change indicator for SG on reagent strip
Bromothymol blue
38
How does urine become alkaline
loss of Carbon dioxide and production of ammonia from urea
39
What are the pH methods
Litmus paper test
pH indicator paper
pH meter
reagent test strip
40
What color will litmus paper test turn in acidic urine
red
41
What are the color change indicators on pH indicator paper
Bromthymol blue
methyl red
42
When is pH meter used
When exact pH is required
43
How does the pH reagent strip work
Area contains polyionic polymer bound to H+. If reacts with cations in urine, H+ is released causing a change in color
44
What is the average pH for urine
6.0
45
What does urine pH depend on
diet
acid base balance
water balance
renal tubular function
46
When is acidic urine seen
Ketosis
UTI by E. coli
High protein diet
47
When is alkaline urine seen
UTI by bacteria that split urea into Ammonia (Proteus, Psuedamonas)
Severe vomitting
Vegetarian diet
Chronic renal failure
48
tamm-Horsfall protein is secreted by
Ascending limb of the loop of henle
49
What does proteinuria mean
>150mg per 24 hour
50
What is Glomerular proteinuria
Due to increased permeability of glomerular capillary wall
51
What are the 2 types of glomerular proteinuria
Selective
non selective
52
What is selective glomerular proteinuria
When glomeruli can retain large molecular weight proteins but allow passage of comparatively lower molecular weight proteins
53
What is non selective glomerular proteinuria
With further glomerular damage, the selectivity is lost and larger molecular weight proteins (gamma globulins) are also excreted along with albumin
54
What is the most severe degree of proteinuria
Nephrotic syndrome
55
Lab values for nephrotic syndrome
>3.5 protein in 24 hour
<3.0 alumbin
generalized edema
hyperlipidemia >350 serum cholesterol
lipiduria
56
What low weight proteins are reabsorbed by the proximal renal tubules
Beta2-microglobulin
retinal-binding protein
alpha1-microglobulin
free immunoglobulin light chains (Bence Jones Protein)
57
When is tubular type proteinuria seen
acute and chronic pyelonephritis
Heavy metal poisoning
tuberculosis of kidney
interstitial nephritis
cystinosis
Fanconi syndrome
rejection of kidney transplant
58
How do we test for purely tubular proteinuria
NOT reagent strip
Heat and acetic acid test and SSA
59
What proteins can overflow from plasma into urine
immunoglobulin light chains
hemoglobin
myoglobin
lysozyme
60
What is hemodynamic proteinuria
alteration of blood flow through the glomeruli causes increased filtration of proteins
61
What is postural proteinuria
occurs when the subject is standing or ambulatory, but is absent in recumbent position
62
why is postural proteinuria happen more in adolescents
due to lordotic posture that causes inferior venocaval compression between the liver and the vertebral column
63
What is post renal proteinuria
caused by inflammation or neoplastic conditions in renal pelvis, ureter, bladder, prostate, or urethra
64
How does the protein reagent strip work
Strip is coated with an indicator and buffered to an acid pH which changes color in the presence of proteins
**protein error of indicators**
65
What is the protein indicator color
bromophenol blue
66
what is the indicator buffer pH for protein reagent strip
3.0 with citrate
67
What proteins can give the protein reagent strip a false negative
Bence jones proteins
myoglobin
hemoglobin
68
What can give the protein reagent strip a false positive
highly alkaline
gross hematuria
contamination with vaginal secretions
69
what is the sensitivity for protein on the reagent strip
5-10mg/dL
70
what color is positive for protein on reagent strip
blue-green
71
What methods do we use for quantitative estimation of proteins
Biuret reaction
Esbach's albuminometer
Turbidimetric
Immunologic
72
What are the protein/creatinine qualitative ranges
<0.2 Normal protein/creatinine ration
0.2-1.0 Low-grade proteinuria
1.0-3.5 moderate
>3.5 nephrotic-range proteinuria
73
What is microalbuminuria
Urinary excretion of 30-300 mg/24 hrs
or
2-20mg/dL of albumin in urine
74
What do we use microalbuminuria for
It is the earliest sign of renal damage in diabetes mellitus
75
What is the independent risk factor for cardiovascular disease in diabetes mellulitis
microalbuminuria
76
How do we detect microalbuminuria
albumin-creatinine ratio in random urine
albumin in an early morning or random urine sample
albumin in 24 hour urine
77
What are Bence Jones proteins
monoclonal immunoglobulin light chains
78
What makes Bence Jones Proteins
neoplastic plasma cells
79
What is the characteristic Bence Jones Protein thermal behavior
When heated they precipitate (40-60)
Precipitate disappear at 85-100
Rapper when cooled to 60-85
80
Where is glucose reabsorbed in the kidneys
proximal renal tubules
81
What is detectable glucose in the urine called
glycosuria
82
What is the renal threshold for glucose
180 mg/dL
83
When is glycosuria with hyperglycemia seen
1. endocrine diseases
2. non-endocrine diseases
3. Drugs
4. Lag-storage glycosuria
84
What are the endocrine diseases that are associated with glycosuria and hyperglycemia
Diabetes mellitus
acromegaly
cushing's syndrome
hyperthyroidism
pancreatic disease
85
What are the non-endocrine diseases that are associated with glycosuria and hyperglycemia
central nervous system diseases
liver disorders
86
What is Lag-storage glycosuria
Alimentary glycosuria
*after a meal the glucose load goes over the renal threshold
87
What is the Benedict 's Copper Reduction Test
Qualitative test
Blue alkaline copper sulphate is reduced to red-brown cuprous oxide if a reducing agent is present.
**Not specific for glucose
88
What is the Clinitest sensitivity for glucose
200 mg/dL
89
What is the glucose reagent test based on
Glucose oxidase-peroxidase reaction
90
Glucose + oxygen -----glucose oxidase =
Gluconic acid + Hydrogen peroxide
91
Hydrogen peroxide + Chromagen -----peroxidase =
Oxidized chromogen (Blue) + Water
92
What will cause a false positive glucose result
Oxidizing agents
-bleach or hypochlorite
93
What will cause a false negative glucose result
Large amounts of ketones
salicylates
ascorbic acid
severe E. coli infection
94
What do ketones in urine indicate
Excessive fatty acid metabolism
95
Wha is the most common ketone
beta-hydroxybutyric acid
96
What is the step to achieve a ketone
Free fatty acid
Acetoacetyl CoA
Acetoacetate
B-hydroxybutyric acid or acetone
97
What are causes of ketonemia
1. uncontrolled Type 1 or 2 diabetes mellitus with ketoacidosis
2. gylcogen storage disease (von Gierke disease)
3. Decreased availability of carbs in diet
4. increased metabolic needs
98
If glycosuria is present what must we test for
ketone bodies
99
Glycosuria + ketone bodies =
diabetes mellitus with ketoacidosis
100
ketone bodies in urine can mean
impending ketoacidotic coma
101
What are the proportions of ketone bodies in urine
78% b-hydroxybutyric acid
20% acetoacetic acid
2% acetone
102
Ferric chloride tests only detect
acetoacetic acid
103
What is the method for the detection of ketone bodies in urine
Rothera's test
Acetest tablet
ferric chloride
reagent test strip
104
What is the classic test for ketones
Rothera's Nitroprusside test
105
How does rothera's test work
Acetoacetic acid or acetone react with nitroprusside in alkaline solution to form a purple color
106
How sensitive is Rothera's nitroprusside test
1-5mg/dL of acetoacetate
10-25 acetone
107
what can cause a false positive rothera's nitroprusside test
L-dopa in urine
Phenylketonuria
108
Steps in Rothera's test
1. 5mL urine in tube and saturate with ammonium sulphate
2. add a small crystal of Na nitroprusside
3. slowly run along the side ammonia to form a layer
4. immediate purple color is a positive
109
Reagent test strip for ketones
Acetoacetate + Na nitroprusside + glycine
Alkaline pH
= purple color
110
what do the acetest tablets mimic
rothera's
111
what do the acetest tablets contain
sodium nitroprusside
glycine
alkaline buffer
112
What is more sensitive for ketones than reagent test strip
acetest tablet
113
Ferric chloride test is how sensitive for ketones
25-50 but is not specific for ketones
114
When bilirubin is bound to albumin circulating in the blood it is called
unconjugated
115
What bilirubin is not water soluble
unconjuctated
116
What does bilirubin combine with to form conjugated bilirubin
Glucuronic acid
117
What bilirubin is water soluble and can appear in urine
conjugated
118
When is bilirubin seen in urine
Hepatocellular jaundice
obstructive jaundice
119
If the person is febrile and has bili in the urine what does that suggest
hepatitis
120
What is the reagent for the bilirubin reaction on reagent test strip
diazo
121
what does urinary excretion of urobilinogen show
diurnal variation with highest levels in the afternoon
122
Reasons for increased urobilinogen in urine
1. hemolysis
2. hemorrhage
123
Reasons for reduced urobilinogen in urine
1. obstructive jaundice
2. reduction of intestinal bacterial flora
124
125
A pink color is produced if urobilinogen reacts with?
ehrlich's reagent
(p-dimethylaminobenzaldehyde)
126
What interferes with ehrlich's aldehyde test
bilirubin
127
Diseases that cause hematuria
glomerulonephritis
Berger's disease
Lupus nephritis
Henoch-Schonlein purpura
Calculus
tumor
infection
tuberculosis
pyelonephritis
hydronephrosis
polycystic kidney disease
trauma
128
How many RBC must be seen in microscopic examination to be hematuria
3+ per high power field
129
Chromogens used for hematuria chemical test
benzidine
orthotoluidine
guaiac
130
H2O2 + chromogen in alkaline pH and RBC =
Oxidized Chromagen + Water
131
Reagents in Ketone Tests that are positive with hematuria, hemoglobinuria, myoglobinuria
Benzidine test
orthotoluidine test
reagenst strip
132
False positives for RBC in urine
Menstrual blood
oxidizing agents (hypochlorite or bleach)
microbial peroxidase in UTI
133
False negatives for RBC in urine
reducing agent like ascorbic acid in high concentration
134
what is hemoglobinuria
free hemoglobin in urine
135
causes of hemoglobinuria
hematuria with subsequent lysis of RBC in low SG
intravascular hemolysis
136
When will hemoglobin appear in urine
when haptoglobin is completely saturated with hemoglobin
137
causes of intravascular hemolysis
Infections
Trauma to RBC
G6PD deficiency after exposure to oxidant drugs
Immune hemolysis (transfuse reaction)
Paroxysmal cold hemoglobinuria
Paroxysmal nocturnal hemoglobinuria
HUS
DIC
138
What is hemosiderinuria
hemosiderin in urine
139
what does hemosiderinuria indicate
presence of free hemoglobin in plasma
140
When is hemosiderinuria seen
Intravascular hemolysis
141
Where is myoglobin found
protein present in striated muscle (skeletal and muscular)
142
What is the role of myoglobin
binds oxygen
143
What test is used for screening of myoglobinuria
ammonium sulfate solubility test
144
How do gram negative bacteria produce nitrites
reduce the nitrates to nitrites through the action of bacterial enzyme nitrate reductase
145
How long must urine be in bladder for conversion of nitrate to nitrite
4 hours
146
What of UTI are detected with nitrite testing
70%
147
What is the Nitrite reagent pad impregnated with
p-arsanilic acid
tetrahydrobenzo(h)quinolin-3-ol
148
How do we get the color change in Nitrite testing
Arsanilic acid converts to diazonium salt which changes to pink if quinolol is present
149
What does leukocyte esterase detect
esterase enzyme from granules of leukocytes
150
what does leukocyte esterase test entail
Pyrrole amino acid ester which liberates 3-hydroxy-5-phenylpyrrole
Reacts with diazo salt to create purple
151
Sensitivity of leukocyte esterase
5-15 granulocytes
152
Negative interference in leukocyte esterase
Elevated glucose
High SG
Presence of cephalexin, cephalothin, tetracycline
High concentrations of oxalic acid
153
What are the organized substances in urine micro
RBC
WBC
Epi
Casts
Bacteria
Parasites
154
What are the unorganized substance in urine micro
Crystalline
Amorphous material
155
What are cellular elements best preserved in
Acid, hypertonic urine
156
What do cellular elements deteriorate in
alkaline, hypotonic
157
What can be added to urine to preserve it
1 crystal of thymol
1 drop of formalin (40%)
