What are the 5 major functions of the kindney?
1) Remove waste products; primarily nitrogenous wastes from protein metabolism and acids, 2) Retention of nutrients, such as: electrolytes, protein, water, and glucose, 3) Acid-base balance, 4) Maintain water and electrolyte balance, 5) Hormone synthesis (erythro protein, renin, vitamin D)
The urinary system consists of these four interconnected parts:
Kidneys, ureter, bladder, urethra
Most important part of the urinary system
Two, kidney bean-shaped organs located on the back of the abdominal cavity near the spinal column
The principal function of the kidney is:___________, Other functions include: ______
The formation of urine; regulate water, acid/base, and electrolyte balance
The formation of urine involves the removal of waste products from the blood (_____), and the retention of essential substances (______)
Each kidney weighs what?
Kidneys are larger in the female in the male. True or False.
What are the six major parts of the kidney?
the capsule, cortex, medulla, renal pelvis, renal arteries, and renal veins
The functional unit of the kidney
Funnel shaped tubules 10 to 12 meters long, muscular organs that go from the kidneys to the back of the bladder at a slight angle
What is the function of the ureter?
Carry urine from the kidneys to the bladder
How do the ureters transfer urine to the bladder?
Gravity and waves of contractions
A contractible sac that lies in the lower abdomen and serves as a reservior for the urine
What is the capacity of the bladder?
A tubule that carries urine from the bladder to the outside of the body
What is special about the urethra of the male?
Serves as both the passage of urine and semen
The outermost shell or lining, which encloses and protects the kidney
The capsule is made up of how many layers?
What are the functions of each layer of the capsule?
Intermost First Layer- directly surrounds the kidney, Second Layer- middle layer of fat that protects the kidney, Outermost Third Layer- surround kidney and anchors it to surrounding structures
The outermost region of the kidney, just inside the capsule
This area of the kidney contains the functional filtering units of the kidney called the nephron units
How many nephrons are present in the kidney?
Each nephronis made up of the: (5)
glomerulus, proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting ducts
Consists of coiled capillaries inside the Bowman's capsule
Semi-permeable membrane in the nephron in which the filtration takes place
Afferent arterioles take blood ____ the kidney, while efferent arterioles take blood _____ the kidneys
to, away from
What is the job of the proximal convoluted tubule?
To reabsorb substances before they are excreted in the urine
What percentage of fluid and electrolytes is reabsorbed by the proximal convoluted tubule?
The maximum amount of an analyte that will be reabsorbed from the glomerular filtrate and controls the amount which is reabsorbed
The reddish brown inner region of the kidney that contains the collecting tubules and renal pyramids
Collect the urine formed by the nephrons and carry it to the ureters; found in the medulla
How many renal pyramids are found in the medulla?
Triangular structures foudn in the medulla and serve as collecting points for all the collecting tubules of the nephron units
The second twisted regions of the Loop of Henle
Distal Convoluted Tubule
Explain the final reabsorption of sodium in order to maintain water/electrolyte balance
Final reaborption of sodium takes palce in the distal convoluted tubule. Renin, an enzyme, is released. Released Renin forms angiotensin and causes the secretion of aldesterone. Kidneys, in response to the aldesterone, actively retains sodium and passively retains water
Water reabsorption is controlled by?
In the distal convoluted tubule, excess acid is also removed from the body. This helps in:
maintaining the body's pH balance
Collecting ducts slant in the _____ and end in the _______
Long, straight portions of the nephron after the distal convoluted tubule that lead to the renal pelvis, and establishes the final concentration of urine while under the control of APH
These are present in the brain and monitor the level of sodium in the blood stream
This is released when sodium concentration is high in an effort to prevent additional water loss
A funnel shaped cavity in the kidney that funnels the urine from the collecting tubules to the ureters
These blood vessels carry the blood from circulation to kidneys; carrying the blood that is going to be filtered
These are the veins carrying blood away from the kidneys; carrying the blood that is going to be filtered
What is the funciton of the urinary system?
To filter out certain substances fromt he blood such as waste products and excess fluids
A modified ultrafiltrate of the plasma
What are the three main processes involved in urine formation?
1) Filtration, 2) Reabsorption, 3) Secretion
How much blood, on average, flows through the kidneys every minute?
On average, how long does it take the entire volume of blood in the body to be filtered?
Having more solids in the blood, the higher the presssure. As a result, a filtering of material will be from _____ to _______
An area of high pressure, an area of lower pressure
The filtrate is essentially free of _____. Why?
Plasma protein and blood cells, the molecules are large and only smaller molecules can make it through the glomerulus
After filtration, blood becomes _____
Substances are ______ reabsorbed or secreted by the kidneys, resulting in urine
The mechanisms of reabsorption include:
active transport, passive transport, osmosis
The movement of a molecule from low area of concentration to a high area of concentration
The method of molecular transport requires energy
What form of energy is used during active transport?
The movement of molecules from an are of high concentration to an area of low concentration
This type of molecular transport does not require energy
In passive transport, the molecules are said to follow a:
Natural concentration gradient
This transport method deals only w/ the movement of water
Maximum amount of a substance that can be reabsorbed
The level of substance that is greater than the reabsorption capacity of the kidney and the excess substance remains in the urine filtrate
When the concentraion of a certain substance in the blood becomes too high, it may be _____ from the kidneys to the urine; also used to eliminate substances that are too large to be filtered by the glomerulus
What is the primary purpose of secretion?
To regulate acid-base balance via secretion of hydrogenious and maintain the 7.4 pH of blood
Urine consists of:
Urea and other organic and inorganic chemicals and water
What percentage of urine is urea and other organic and inorganic chemicals?
What percentage of urine is water?
The concentration of the dissolved elements in urine varies based on which criteria? (5)
dietary intake, physical activity, metabolism, hormones, and body position
Organic substances in urine include mainly:
urea, creatinine, and uric acid
Inorganic substances in urine include mainly:
sodium, chloride, and potassium
True or False: Urine is a biologically hazardous substance
Urine samples should be collected in a ________ w/ a ________
clean disposable container, screw top lid
A urine specimen must be delivered to the lab w/ in what time period?
If the specimen cannot be delivered to the lab w/ in 30 min, it should be _____ for up to ______
refrigerated, 8 hrs
If a delay in testing occurs, what must happen to the urine?
it must be preserved
There are two methods of urine preservation. What are they?
physical and chemical
What is the best method of preservation for short periods of up to 8 hours, or during a 24-hour urine collection?
If a urine is preserved using refrigeration, what must you make sure to do before analysis?
The sample must be brought back to room temp.
Refrigeration is an example of what method of urine preservation?
Preservation in which preservatives are added to the urine either after or during collection
For the best result, which method of urine preservation should be used?
Both should be used together for best results
Preferred characteristics of chemical preservatives include: (4)
Bactericidal, inhibits urease activity, preserves formed elements, does not interfere w/ testing
Preservative used to preserve the cellular materials found in urine; may cause false positive test for glucose
Preservative used to retard and prevent bacterial growth
Toluene, phenol, and thymol
Preservative used to maintain pH to help preserve cellular and chemical elements of the urine; also retard bacterial growth
Preservative that is a convenient method w/ controlled concentration of chemicals to minimize interference
Commercial Preservative Tablets
Preservative that prevents glycolysis and is good for drug analysis
Changes in unpreserved urine include:
Increase in bacteria, turbidity (precipitation of amorphous sediments); Decreased ketones, bilirubin (exposure to light), urobilinogen (due to oxidation); Deterioration of formed elements, Color change due to oxidation/reduction of metabolites
What are the effects of increased bacteria?
deteriorate specimen, urea to ammonia, increase pH, may use up glucose as a food source, nitrates to nitrites, increased turbidity
Most commonly used urine specimen?
Random specimens are primarily collected for?
What is included in a routine urinalysis?
Color, pH, Appearance, S.G., and Microscopic examination
A random specimen requires a minimum of what volume? Collected in?
10-15 ml. a non-sterile container @ anytime of the day
What do you do if an abnormal finding is collected in a random urine sample?
Have the patient recollect under more controlled conditions
This type of specimen is collected immediately upon arising
First morning specimen
What is the benefit of a first morning specimen?
It represents a concentrated specimen
A first morning urine specimen must be delivered to the lab w/ in:
A first morning specimen is essential for:
preventing false neg pregnancy tests and evaluating orthostatic proteinuria
The patient is instructed to void two hours after consuming a normal meal describes which urine specimen?
Two-hour post prandial
Two hour post prandial urines are used to test ______ and to maintain patients w/ _________
glucose, diabetes mellitus
During a glucose tolerance test, a _______ is collected and tested for glucose before a glucose tolerance test is performed
fasting urine sample
24 hour urine samples are collected often for a ______ than a ______
quantitative analysis, qualitative analysis
In a 24 hour urine sample, is the first morning sample collected as well? 1st morning? 2nd morning?
No, the first morning urine is voided and discarded
Yes, the urine is voided and added to the previously collected period
What is the average normal adult daily output of urine?
Performed when a patient is at risk to infection or perforation or the urethra or bladder by the physician or nurse inserts a catheter (hollow tube) in the urethra of he bladder
Catheterized specimens are primarily used for:
microscopic examinations and microbiological cultures
Which part of a catheterized routine urinalysis is performed first?
A safer, less traumatic method of obtaining urine for bacterial culture, also offering a more representative and less contamination
Mid-Stream Clean Catch
How does a midstream differ from a MSCC specimen?
A midstream collection is the same as a MSCC except, a sterile container is not required and the external genitalia do not have to be washed
A suprapubic specimen is collected by who?
Sample in which a needle is placed directly into the bladder through the abdomen to obtain urine for bacterial culture or cytological exam
What are the methods that may be used to get urine from a pediatric patient that is not "potty-trained"?
Sterile plastic bags, cath, or suprapubic
Macroscopic urinalysis includes:
volume, color, appearance, pH, and S.G.
Factors that affect the volume of urine excreted in a 24 hour period are?
fluid intake, fluid loss, diuretics (tea or coffee), and pathologic states (diabetes, renal failure, and obstruction)
What is the chief factor in determining the volume of urine?
Intake of water and other fluids
Normal (adult) output of urine
600-2000ml in 24hours
Average daily output of urine for adults
1200-1500 ml in 24 hours
Which of the following does not increase output of urine: Drugs, caffiene, alcohol, diabetes mellitus, and diabetes insipidus
None of the above, all increase output of urine
What conditions can cause reduced urine output?
Renal failure, glomerular dysfunction
Urine output below 500 ml in 24hours
Complete suppression of urine output
Excessive urination @ night
Urine output above 2000ml in 24hours
Passage of abnormally large amounts of urine for a specific patient
The normal color of urine is a result of the prescence of which pigment?
Specimens should be reported as _____ only when no pigmentation can be seen when viewed against a white background
Normal urine colors include:
Straw, yellow, amber
Bilirubin or medication
Hemoglobin, myoglobin, RBCs, beets, PSP dye, or food w/ dyes
Bright or dark orange
Melasin, methemoglobin, methyldopa, or hemogenistic acid
Pseudomonas spp. (pigment-producing bacteria
Bright or dark blue
Urine appearance can be reported as:
clear, hazy, cloudy, or opaque
A urine that can be seen through easily is reported to have an appearance of ______ and is usually indicative of:
Clear, normal dilute urine
A urine that can be seen through w/ difficulty and is reported as _______ and indicative of:
Hazy, small amounts of phosphate, urates, or cellular material (normal if stored properly, WBCs or RBCs in high amounts (abnormal))
A urine that cannot be seen through is reported to have an appearance of ______ and is usually indicative of:
Cloudy, large amounts of phospate, urates or cellular material (normal if stored properly, WBCs or RBCs in high amounts (abnormal))
A urine sample that cannot be seen through, nor will light pass through is reported to have an appearance of ______ and is usually indicative of:
Turbid (Opaque), WBC/RBC , epithelial cells, bacteria
Is odor part of the usual urinalysis exam?
Urine w/ bacterial infection smells?
Very strong, unpleasant
Urine w/ diabetes mellitus smells?
Sweet or fruity
Urine w/ maple syrup urine disease smells?
Is foam a part of the usual urinalysis exam?
White foam is indicative of?
Yellow foam is indicative of?
The density of a solution compared w/ the density of DI water @ a similar temp
What does urine S.G. measure?
Concentrating and diluting function of the kidney
The two most common ways to measure S.G. are?
Reagent strips, refractometer
A composition of the velocity of light in air w/ the velocity of light in solution
What is used to calibrate the refractometer? Confirm that calibration?
DI water, 5% NaCl or 9% sucrose
How much urine is needed to measure S.G. using a refractometer?q
Normal values of S.G.: Random urine? 24 hour urine?
A high S.G. may indicate _______, while a low S.G. may indicate _________
concentrated urine due to dehydration or high dissolved substances; diluted urine due to high fluid intake or kidney disease, diabetes insipidous, low ADH
What is the purpose of the microscopic exam indices of urine?
Detect and identify insoluble materials present in urine
A microscopic examination of urinary sediment must include both a ______ and _______ of the elements present
identification and quantification
Microscopic urine examination must be on a _________
fresh urine sample
It is essential that microscopic examination take place w/ in:
one hour after collection
If urinalysis, microscopic or macroscopic is delayed, the specimen should be:
Why must a urine sample be fresh or adequetly preserved for microscopic examinaion?
formed elements may disintegrate rapidly, particularly in alkaline urine
Which part of the urine sample is examined in a microscopic examination?
If a stain is being used for a microscopic urine examination, it should be added _______ the specimen is agitated for resuspension
How many drops of resuspended urine is used to make a slide for microscopic examination?
During a microscopic examination, first a scan should be done to get a feel for the general composition and larger casts. This should be done on:
During a micrscopic examination, the actual identification should take place after the initial scan on the:
How many fields should be examined during a microscopic examination: low power? high power?
10 low power, 10-20 high power
WBCs, RBCs, epithelial cells, and crystals are reported as:
Casts are reported as:
TNTC stands for:
Too numerous to count
The most frequently used stain in microscopic urinalysis
Sternheimer-Malbin contains ______ and ______
Crystal violet and safranin O
Are stains routinely used for urine microscopic examination?
Finding a few occasional RBCs is considered _______ while finding of more than occassional may indicate:
Normal; kidney or genitourinary tract damage
The more RBCs in the urine:
the greater the extent of the injury
What may cause females in particular to display large numbers of RBCs?
if collected during menstration
What three forms can RBCs be seen in?
Normal (Intact), Crenated, Ghost; also Dysmorphic
Urine w/ a high S.G. is considered _________
hypertonic or concentrated
In concentrated or hypertonic urine, RBCs may appear to have spiny projections, also called ______
Crenated RBCs are a result of:
osmotic pressure removing the intracellular fluid, causing the cell to collapse or shrink
Urine w/ a low S.G. is considered:
RBCs that swell and shrink rapidly, releasing their hemoglobin content and leaving only the cell membranes
RBCs that vary in size, have cellular protrusions, or are fragmented
An increase amount of blood in the urine
Any marked increase or large amount (outside the small numbers normally found) of WBCs is termed:
A majority of WBCs found are:
Hematuria is associated w/ which condition?
Pyuria is associated w/ which condition?
infection or inflammation w/ in the genitourinary tract
In hypotonic urine the cytoplasmic granules of WBCs appear to exhibit Brownian movement. These cells are called _______.
What are the three main types of epithelial cells?
Squamous, Transitional, Renal Tubular
Most common type of epithelial cell found in urine
Large, flat, irregular shaped cells w/ a small, central, distinct nuclei and abundant cytoplasm; originate from lining of the vagina and the lower portion of the male and female urethra w/ little pathological significance
3x the size of WBCs; appear round or pear-shaped w/ a central nucleus and may have tail-line projections; originate from the lining of the renal pelvis, bladder, and upper urethra; seldom pathological
Most significant of epithelial cells
Round w/ an eccentrically located nucleus, slightly larger than leukocytes; may be flat, cubadil, or columnar; line the proximal and distal convoluted tubule
An increased number of Renal Tubular Epithelial Cells indicate __________
Tubular necrosis, tubular damage, or renal graft rejections
What special protein is combined w/ protein to make up all casts?
This protein is often referred to as a "hyaline matrix"
What conditions must be met in order for casts to form?
Decreased pH, Reduced urine flow, Increased protein, High soluble concentration
Most frequently occuring casts
-Appear colorless and transparent
-Have same refractive index as urine
-0-2/lpf considered normal
-May be seen following exercise, dehydration, and heat
-Increased in glomerulonephritis, pyelonephritis, chronic renal failure, congestive heart failure
Hyaline casts in which various structures such as RBCs or WBCs are trapped
How are inclusion casts are named?
According to the elements trapped inside
-Yellow to brown
-Associated w/ any condition that damages the glomerulus, tubules, or renal capillaries
-Indicative of bleeding w/ in the nephron and primarily associated w/ glomerulonephritis, lupus nephritis, subacute bacterial endocarditis and focal glomerulitis
-Refractile and exhibit granules
-Multi-lobed WBCs within w/ visible nuclei
-Indicative of inflammation or infection w/ in the nephron
-Finding occassional cast is not significant
A cast is only reported as a WBC cast if:
it is nearly or completely filled w/ white blood cells
-When epithelial cells slough off from the tubules and adhere to or become incorporated in hyaline casts
-Only present in cases of tubular damage and necrosis
-Usually swollen and tinged w/ yellow/brown color
Epithelial Cell Cast
Epithelial cells that are arranged side-by-side is indicative that they:
came from the same tubule
Epithelial cells that are arranged irregularly indicates that they:
originated from different portions of the tubule
-These casts result from the degradation of cellular casts or the aggregation of serum proteins filtered by the glomerulus
-Initially granules appear large and coarse, and then break down into fine granules as urine flow is decreased
Is it important to differentiate between coarse and fine granular casts? Why or why not.
No, differentiation between coarse and fine granular casts is not important. They are usually just reported out as granular casts.
-Yellow, gray, or colorless casts
-Smooth, homogeneous appearance
-Broad w/ blunt or broken ends
-Edges either cracked or serrated
-Indicates extreme decrease in urine flow and chronic renal failure
-When the breakdown of epithelial lining of the tubules leads to the production of fat droplets instead of granules
-Contain yellowish-brown fat droplets or oval fat bodies
-Indicate disorders causing lipiduria, such as nephrotic syndrome
A positive identification of fatty casts can be made by:
using polarized light to look for Maltese Cross Formations
-Much larger than other casts
-Formed in the collecting ducts
-Indication of renal failure
Which types of casts can occur in broad cast form?
All types of cast may be seen in broad cast form
Is bacteria found normally in urine?
If found in a freshly voided urine specimen, bacteria may indicate what condition?
Smooth, colorless, ovoid cells that may exhibit budding
Which parasites are of concern that are found in urine?
T. vag, S. haematobium, E. vermicularis
Most frequently encountered parasite in urine
T. vag uses what for motility?
With T. vag, _____ may be asymptomatic while ______ my be symptomatic
A blood fluke that dwells in the veins around the bladder, having a characteristic terminal spine
Findings of E. vermicularis in a urine sample would suggest what?
fecal contamination. E. vermicularis normally resides in the folds of the rectum
Parasite that is flattened on one side and rounded on the other; known to cause nephrotic syndrome
These can be found occassionally in urine following sexual intercourse or as a result of nocturnal emissions, and are easily identified based on their head and tail shape
Sperm cells (spermatozoa)
True or False: The prescence of spermatozoa in urine is never significant
False. Spermatozoa within a urine specimen can sometimes be significant and should be reported according to the OI
Appears as threadlike structures w/ a low refractive index and is considered NOT clinically significant
Normal crystals found in acid urine include:
Uric Acid, Amorphous Urates, Calcium Oxalate
If uric acid crystals are present in fresh samples, the possibility exists that this is present somewhere in the renal system
-crystal w/ appearance as a diamond or rhombic prisms, occasionally have six sides
-Increase levels seen in leukemia, Lesch nyhan syndrome and gout
-Appear in a non-crystalline form as a granular precipitate
-Give urine a cloudy pink color
How do you differentiate between amorphous phosphates and amorphous urates?
Based on pH of the urine or by the addition of alkali or heat; amorphous urates are soluble in alkali and heat
-Generally seen as colorless, octahedral (box shaped) crystals resembling small squares crossed by two intersecting diagonal lines ("envelope" appearance)
-May also appear as dumbells or spheres
-Usually a result of diet rich in oxalic acid
How can you differentiate calcium oxalate and calcium carbonate?
Dilute HCl can be added to differentiate
Normal crystals found in alkaline urine include:
Triple Phosphate, Amorphous Phosphates, Calcium Phosphates, Ammonium Biurate, Calcium Carbonate
-Colorless prisms w/ three to six sides, often referred to as "coffin lids"
-Soluble in dilute acetic acid
-Appear as a granular precipitate w/ no definite shape
-Soluble in dilute acetic acid
-Appear as colorless, thin prisms, plates, or needles
-Not frequently seen in urine but, normal in alkaline urine
-Precipitated only when free ammonia is present due to bacterial metabolism in long-standing specimens
-Appear as spherical bodies covered w/ long, irregular spicules
-Soluble in acetic acid or heat
-Crystals seen in small dumbell or spherical shapes
-If acetic acid is added to urine in which Calcium Carbonate crystals are present, what will the result be?
Gas will form
Abnormal urine crystals include:
Cystine, Cholesterol, Leucine, Tyrosine, Renal Calculi
-colorless, highly refractile, hexagonal plates w/ equal or unequal sides
-Occur frequently in cystinuria, an inborn metabolic error
-Large, flat, rectangular, transparent plates w/ a notch in one or more corners
-Referred to as a characteristic "missing corner"
-Indicates excessive tissue breakdown
-Oily, refractive, yellow or brown spheroids possessing radial and concentric striations
-Seen in individuals w/ liver disease
-Very fine, highly refractile needles that occur in sheaves or clusters and are constricted in the middle
-Black in color, esp. in center
-Appear in sever liver disease
Renal calculi are also known as what?
About 75% of all renal calculi are:
What can be done to prevent kidney stone formation?
Modification of diet
-An artifact that resemble casts but are tapered at one end
-Formed at the junction of the ascending loop of Henle and the distal convoluted tubule
-Have same clinical significance as casts
List some examples of contaminants that may be found in the microscopic evaluation of a urine specimen
Fecal contamination, wood fibers, oil droplets, starch granules, pollen grains, cotton, hair, talc granules
Which crystals are considered ALWAYS clinically significant?
Tyrosine, Cystine, Cholesterol, Leucine
Review page 1-25 table
What is used to lyse RBCs when identification of other structures is obscured such as yeast?
2% acetic acid
Plastic strips w/ individual pads impregnated w/ reagents that react w/ the constituents in urine describes which method of urine examination?
What are the two major brands of dipsticks?
Multistix and Chemstrip
Most dipsticks are designed to measure: (10)
Glucose, Bilirubin, Ketones, Specific gravity, Blood, pH, Protein, Urobilinogen, Nitrite, Leukoasterase
For the dipstick method, the strip must be adequetly moistened for how long?
1 second, also called 'wetting'
a common source of error regarding the 'wetting' of the dipstick is:
allowing it to sit too long
Drawing the strip over the edge of the container, touching to an absorbent paper, and holding the strip _______ are all recommended to prevent _______ throughout the dipstick procedure
What are the criteria for storing and preserving strips?
-Store in a tightly capped container @ recommended temps
-Moisture, direct light, heat, or volatile substances will deteriorate the strips
-Do not use past their expiration date
-Check for discoloration and dispose if it is present
When must positive and negative dipstick controls be run?
each day patient testing occurs and when new reagent bottles are opened
Urine pH must always be performed on:
freshly voided urine specimens
A reflection of the body's ability to regulate the acid-base balance in the body
A fresh random urine sample usually has a pH of what range?
This is the most widely used method of pH determination
Color indicator tests
What two indicators are most widely used to detect pH
bromthymol blue and methyl red
Methyl red detects pH changes in the range of:_____________, while bromthyl blue detects changes in the range of: __________
4.4-6.2 (red-yellow); 6.0-7.6 (yellow-blue)
Sample w/ a pH of ____ indicates improper preserved specimen and cannot be tested
What is of concern to the pH test pad if excess urine remains on the dipstick?
Urine may run off the nearby protein pad onto the pH pad
What are the possible sources of error for the dipstick pH testing method?
-Delayed processing can cause alkaline urine
-Run-off from the protein pad can cause falsely acidic
What is the confirmatory test for pH?
There is no confirmatory test for pH. But if an exact measurement of urine pH is needed, a pH meter is used
This test is considered the best overall urine test for detection of kidney disease
An increased amount of protein in the urine
In proteinuria, most proteins excreted in abnormal amounts are:
This serum protein is most frequently present in the urine in kidney disease where proteinuria is involved, making up 60-90%, due to low molecular weight
These proteins are in some diseases, particularly multiple myeloma
Abnormal globulins (BENCE-JONES proteins)
Proteins that may be present in urine include:
Plasma proteins, serum proteins, albumin, bence-jones proteins, Tamm-Horsfall proteins, mucus, and protein from prostatic, seminal, and vaginal secretions
True or False: Proteinuriais not always indicative of renal disease
True. However, its prescence in urine does require additional testing to determine if the protein is normal or pathologic
Major causes of proteinuria include:
Glomerular membrane damage, tubular damage, pre-renal disorders, increased serum levels, renal proteinuria, orthostatic proteinuria, microalbuminuria
Benign proteinuria can be produced by conditions such as:
exposure to cold, strenuous exercise, high fever, dehydration, orthostatic or postural proteinuria
The prescence of protein is related to the body position in the patient; protein is present in long periods in a vertical position and disappears when a horizontal position is assumed
How is a diagnosis of orthostatic proteinuria made?
The patient is asked to collect a urine sample upon rising in the morning, and then collect a urine sample after several hours remaining in a vertical position. The first morning specimen will be negative for protein while the second specimen will be positive.
If proteinuria occurs late in a pregnancy it may be an identification of a :
Procedures for the determination of urinary proteins are divided into three groups including:
screening tests (dipstick), semi-quantitative tests, and quantitative tests
The simplest test for urine protein screening is:
the dipstick test
The protein test on the dipstick uses the principle of __________. Explain.
Protein error of pH indicator. Test is based on the ability of proteins to alter the color of some acid-base indicators w/o changing the pH
The protein pad on the dipstick contains a ________ indicator. At a pH of 3, abscence of protein will cause a _______ color, and the presence of protein will cause a ______ color
Tetrabromphenol blue, yellow, green and then blue
Results of the dipstick protein method are graded as:
negative, trace, 1+, 2+, 3+, 4+
What are the possible sources of error for the protein dipstick test?
-Highly alkaline urine causes blue color change not related to protein
-Prolonged contact will cause blue color change not related to protein
-Stongly pigmented urines
-Proteins other than albumen present, due to low specificity of strips
Does the protein dipstick test determine the presence of all protein?
No. The dipstick is more sensitive to protein albumin and less sensitive to globulins, hemoglobin, Bence-jones, or mucoproteins. A negative result does not rule out the presence of these other proteins.
What is described as when small amounts of albumin will leak into the urine?
What is the difference between the measurements of the microalbumin strip and the protein reagent strip?
Units for Microalbumin reagent strip are mg/L
Units for protein reagent strip are mg/dL
True or False: ALL positive dipstick for protein must be followed by a more sensitive test
All positive urines for protein will be followed by the semi-quantitative method called _________, which is a type of ________
Sulfosalicylic Acid (SSA); precipitation test
What is the confirmatory test for Protein detection?
SSA is a simple method of ______________ urine protein
What percentage of SSA precipitate is used in the SSA method of protein urine detection?
Sources of error for the SSA test include:
-Uncentrifuged, turbid specimens
-Highly alkaline urines
A low molecular weight protein that is produced in patients w/ multiple myeloma; an immunoglobulin (IgD) that can be found in urine
Bence-Jones proteins precipitate between ___________ and re-dissolve again near ______
Two methods that can be used to detect Bence-Jones protein are:
electrophoresis and immunoelectrophoresis
Although _______ is the most commonly found sugar in urine, __________, ________, _______, and ______ may also be found under certain conditions
Glucose.; lactose, fructose, galactose, and pentose
The presence of glucose in the urine is termed __________ or ______
glucosuria or glycosuria
Glucosuria or glycosuria can be found in:
Diabetes mellitus and gestational diabetes
Urine glucose tests for _______ rather than renal problems
What kind of specimen is best for a glucose test? Why?
Fasting specimen is best because glucose may appear in urine following a meal
The two types of tests most frequently used to detect glucose are:
1) enzymatic test, 2) reduction tests
Explain the principle of the glucose test using the dipstick
Based on the double sequential enzyme reaction called "glucose oxidase procedure", producing a color
How are results on the glucose dipstick test reported?
Neg, Trace, 1+, 2+, 3+, 4+
Sources of error for the dipstick method of glucose detection include:
-Contamination w/ strong oxidizing agents
-Trace value in dilute specimen
-Strips exposed to air
-High Ascorbic acid (Vitamin C)
Can the dipstick test be used to detect sugars other than glucose?
No. The dipstick test is specific for glucose and can ONLY be used to test for glucose.
What is the principle of the Clinitest?
ability of glucose and other sugars to reduce copper sulfate in the presence of alkali and heat
What is the confirmatory test for glucose?
Historically, the copper reduction test for glucose detection used a reaction mixture called ______; today the principle used is put into the ________
Benedict's solution, Clinitest tablet
When using the Clinitest a negative result will produce __________ while a positive result will produce _______
a blue color, a green/yellow/orange/brick red color
All positive result on the Clinitest are reported as
Sources of error for the Clinitest include:
-High ascorbic acid (vit C)
-Radiographic contrast media
-Mixing test tube before the 15 sec wait after bubbling stops
What is the difference between the Reagent Strips and the Clinitest for glucose detection and how they are affected by vitamin C (ascorbic acid)?
False neg - Reagent strip
False pos - Clinitest
Which is a more sensitive method for detection of glucose: the Clinitest or the dipstick
The dipstick is more sensitive than the Clinitest
What can cause a strong positive dipstick and a negative Clinitest?
What can cause a positive Clinitest and a negative dipstick?
Strong oxidizing agents
Sugars other than glucose such as Galactose, Fructose, Pentose, and Lactose
Which sugar is most clinically significant and of concern when found in the urine of newborns? Why?
Galactose, it represents an "inborn error of metabolism" and can result in a failure to thrive and other complications
Which test should be performed w/ the glucose oxidase on all infant urines? Why?
the Clinitest, to detect the presence of any Galactose
Ketones are by-products of _________
There are three types of ketone bodies including:
1) Acetoacetic Acid-2%, 2) Acetone-20%, 3) Betahydroxybutric acid-78%
A detectable level of urine ketone bodies
Ketone are a normal finding in the urine of healthy individuals. True or False.
False. Ketones are not normally found in the urine of healthy individuals
The most commonly used test for the detection of ketonuria is:
Sodium nitroprusside test of Rothera, most commonly on the dipstick
Testing for urine ketones is done mainly to:
monitor diabetes mellitus or starvation
The dipstick method detects _________, but not _______ or ________ rather assuming ther presence. Why?
Acetoacetic Acid, acetone or betahydroxybutric acid. These two are simply derived from acetoacetic acid and are therefore assumed to be present if acetoacetic acid is there.
For detection of urine ketones:
Chemstrips do not measure _____________
Multistix/Ketostix do not measure ________
acetone or betahyroxybutric acid
The ketone pad on the dipstick test must be read @:
The ketone test is reported as:
neg, trace, small, moderate, large
Sources of error for the ketone dipstick test include:
-Highly colored urine
-Improper preservation or left at room temp too long leads to breakdown of acetoacetic acid by bacteria
What is the confirmatory test for urine ketones but, may also be used for serum, plasma, or whole blood?
What is added to the Acetest for better color differentiation?
The presence of blood is (abnormal/normal?) and is a good indicator of:
abnormal; renal dysfunction or kidney or urinary tract trauma
Presence of blood in the urine is ALWAYS significant. True or False.
Blood may be found in two different forms. What are they?
Intact RBCs or free hemoglobin
The presence of intact RBCs in urine
The presence of free hemoglobin in urine
Hematuria is often a result of ______________, while Hemoglobinuria may be a result of _______
disease or trauma to the kidney or urinary tract, lysis of the RBCs already in the urinary tract or by intravascular hemolysis
The most accurate way to detect blood in urine are ________, such as ________ although they cannot differentiate between hemoglobinuria or hematuria.
Chemical test, dipsticks
What can be done to differentiate hematuria from hemoglobinuria if a dipstick is positive for blood?
microscopic examination. intact RBCs can be seen in a microscopic examination and dipstick chemical testing while free hemoglobin can only be detected through chemical testing
A protein found in muscle tissue that reacts positively w/ the dipstick test for blood
Myoglobin produces a _________ urine but, a _______ serum
The dipstick test for blood in the urine is based on the peroxidase-like activity of hemoglobin as it acts like an enzyme, also called ____________
Although a speckled pattern on a dipstick may indicate the presence of _______, and a solid color may indicate the presence of ______, it cannot be definitive which is present simply based on the dipstick test
True or False: Differentiation can be made between hematuria and hemoglobinuria based on the dipstick test results alone.
False. The presence of blood in the urine may be determined in one of its two states but, microscopic evaluation is required to differentiate between the two.
Sources of error for the blood reagent strip include:
-Strong oxidizing agents
-Microbial peroxidase assoc. w/ UTI
-Blood from menstruation
-Testing supernatant after centrifugation
-Elevated S.G. or protein cause RBCs to lyse
-Ascorbic Acid (Vit C)
-Captopril (antihypertensive meds)
-High nitrite levels in UTIs
Results from the breakdown of hemoglobin that is released when RBCs are destroyed
Why is the normal urine bilirubin considered to be negative even though normal urine bilirubin is about 0.02 mg/dl?
Screening tests for bilirubin are not sensitive enough to detect this amount, so the normal urine bilirubin is considered negative
Increased levels of bilirubin in the urine are a often a result of:
Liver diseases such as hepatitis and cirrhosis and bile duct obstruction
An increased level of bilirubin
Dipstick may be used to provide _____________ results of urine bilirubin
Reagent tablets to detect bilirubin (Ictotest) may be used w/ either ______ or _______
serum or urine
Reagent strip/Reagent tablet has great sensitivity to detect bilirubin
The principle behind the reagent tablet and the dipstick of bilirubin testing is the:
This is impregnated in the dipstick pads and reacts w/ bilirubin in urine to produce a color
Sources of Error of the Dipstick test for bilirubin include:
-Lodine (drug) metabolites
-Indican: waste product
-Oxidation of bilirubin to biliverdin (Exposure to UV light)
- Ascorbic Acid
-Elevated nitrite levels, UTI's
All positive and questionable results of bilirubin should be tested using the confirmatory test for bilirubin, the ____________
The Ictotest, in comparison w/ the dipstick test, for bilirubin is:
The most common error in using the Ictotest to detect bilirubin is:
using specimens that are not fresh, bilirubin is rapidly destroyed by light
Sources of error for the Ictotest to detect bilirubin include:
-Exposure to room air makes bilirubin undetectable due to oxidization
Bacterial action w/ in the intestinal tract convert bilirubin to a group of compounds known as ______
For urobilinogen, small amounts are excreted in the ________ but the majority of it is excreted in the ______
The concentration of urobilinogen in normal random urine is:
0.2 to 1.0 Ehrlich units/dl (EU/dl)
Urobilinogen is measured in a special units called _________
Urobilinogen urine output is increased in:
liver disease and hemolytic disorders
liver obstructions and antibiotic therapy when intestinal bacteria are reduced
The dipstick test for urobilinogen is based on which principle?
the modified Ehrlich reaction
In the modified Ehrlich reaction, this reacts w/ urobilinogen in a strongly acid and a color enhancer to produce results
PABA (Ehrlichs reagent)
What is specific about the type of urine used for the dipstick urobilinogen test?
only strongly acid urines will produce a result, alkaline urines will not produce a result
Explain the detection and reporting of the reagent strip used for urobilinogen detection
Reagent strips cannot detect the absence of urobilinogen. Concentrations of 0.2-1.0 EU/dl are reported as normal, while concentration about 1.0 are reported as 2.0-12 EU/dl.
Which manufacturing type of dipstick uses Ehrlich's reagent to react w/ urobilinogen?
Which manufacturing type of dipstick uses Diazo reaction and diazo salt to react w/ urobilinogen?
Sources of Error for the dipstick method of urobilinogen detection include:
-Ehrlich reactive compounds
-Aldomet (anti-hypertensive drug)
-Pigments and their metabolites
-Tested @ room temp rather than body temp- "warm aldehyde reaction"
-Oxidation to urobilin (delayed testing)
-Most result from exposure to light
-Random samples; urobilinogen excreted w/in 2-3 hrs following meal
What is the confirmatory test for urobilinogen?
There is no confirmatory test for urobilinogen but if confirmatory testing is needed to be done it should be done w/ another reagent strip that uses a different methodology
The nitrite rapid chemical test provides a quick screening for the presence of which condition? And also evaluate?
UTI; effectiveness of antibiotics and evaluate high risk patients for a UTI
Are nitrates a normal finding in the urine of healthy patients?
Yes, nitrates derived from diet are normally found in the urine of healthy individuals
Explain the clinical difference in nitrates and nitrites
Nitrates derived from diet are normally found in the urine of healthy patients however, common UTI organisms contain enzymes that reduce nitrate in the urine to nitrite. This makes the presence of nitrite abnormal and indicates the presence of an infection.
What is the principle of the nitrite dipstick test?
the Greiss reaction
Nitrite dipstick test, like that of the urobilinogen test, will only produce a result if the sample is __________, a ____________ sample will not produce a result
Nitrite is reported as:
positive or negative
A uniform pink color on a nitrite test yields a _________ result, while a spotted pink or pink-edged also yields a _____ result
What does a positive result on the nitrite dipstick method indicate?
The presence of 100,000 or more organisms (bacteria) per ml
Sources of error for the nitrite dipstick detection test include:
-Old urine, resulting in more bacteria
-UTI cause by gram pos bacteria
-Insufficient time in bladder
-Insufficient dietary nitrate to convert
-Too much bacteria reduce nitrite to nitrogen
Any shade of pink on a nitrite dipstick test indicates a clinically significant amount of bacteria. True or False.
Nitrite dipstick test, tests UTI that are onset by:
Gram negative bacteria converting nitrate to nitrite
What is the confirmatory test for Nitrite?
A bacteriological culture and microscopic exam of sediment are the only confirmatory test
It is important that even vague clinical symptoms of UTIs found in a nitrite test are followed up by:
a urine culture
This test detects the presence of leukocytes, screening for possible UTI and inflammatory process
All ________ leukocyte esterase must be followed up w/ what?
positive, microscopic examination
What is the principle behind the dipstick leukocyte test?
Using Diazo reaction: enzymatic reaction using the esterase in leukocytes, reacting w/ diazonium salt to produce purple color
More standardized: Chemical tests or sediment exams for leukocytes. Give an example of why.
Chemical test are more standardized. It would detect leukocytes that have been lysed and would not have been found in a microscopic exam.
A positive leukocyte esterase test w/ no WBCs or bacteria in the microscopic analysis could be caused by:
Chlamydia spp., Trichomonas spp.
Sources of error for the leukocyte esterase dipstick test include:
-Highly pigmented urine
-High glucose and protein
-Antibiotics (cephalexin, cepalothin, tetracycline, gentamicin)
-Oxalic acid (metabolite of Vit. C)
Confirmatory test for the presence of leukocyte esterase is:
While the Clinitek, Atlas, and IRIS are all example of automated urine analyzers, this is the only one that can identify cellular constituents in place of performing a microscopic analysis
What are the advantages and reasons for automation of urinalysis?
-Some eliminate the need for microscopic analysis by identifying cellular constituents
The Clinitek can read how many patients at one time?
up to 100
How often must the optics be calibrated on the Clinitek?
LIS stands for:
Laboratory Information System
True or False: Automated urinalysis machines eliminate transcription errors
False, they reduce transcription errors but, does not eliminate them entirely
How are calibration strips run through the Clinitek?
The same manner as patient samples
How often is the Clinitek needed to be wiped down and disinfected?
Once per shift
What are the advantages of LIS?
-reduce transcription errors,
-decrease turnaround time
True or False: LIS is not completely fail-safe
Link of instruments and personal computers in the laboratory describes which aspect of LIS?
Ability to verify and finalize patient results before sending to the provider describes which aspect of LIS?
If past and present results do not correlate, there will be a flag on the tech's workstation to prompt them to investigate possible causes, this is called a _________
True or False: Two advanced functions of a LIS include standardization of results from different tests onto one standardized report form, as well as patient lab test history
There are three different general categories of renal function tests including:
1) Concentration tests
2) Retention tests
3) Clearance tests
This category of renal function test are helpful in measuring the capacity of the kidney to remove certain substances present in the blood
The type of clearance test to be used is based on the functional aspect of the kidney that is to be evaluated. Some substances are removed by _________ while others are by ________ and _______.
Glomerular filtration alone, glomerular filtration and tubular secretion
______ is an example of a substance that is primarily removed by the glomerulus and measures ___________. Meanwhile, ______ is an example of a substance that is filtered out by ______ and also ________, so it measures _____________.
Creatinine, GFR; Urea, glomerulus, reabsorbed by the tubules, renal function
Which renal function test, the clearance or the BUN test, is more sensitive to a change in kidney function?
What is considered a suitable specimen for clearance tests?
Serum or Urine
Most sensitive chemical method and accurate measurement of glomerular filtration rate
Creatinine clearance test
The creatinine clearance test estimates the blood flow through the kidneys per _________ w/ the complete removal of creatinine
Explain the significance of increased values from a creatinine clearance test
Increased values have no clinical significance and if it occurs a source of error must be suspected
The most common causes for a decreased clearance test result are:
damage to the glomerulus (glomerulonephritis) or damage to the renal tubules (tubular nephritis), as well as reduced renal perfusion (blood flow) to the glomerulus
A waste product formed in muscle and brain tissue as a result of the breakdown of creatine
Creatinine is formed in the liver, removed from the blood by ________, and (is/is not) reabsorbed by the tubules; therefore nearly all of creatinine is excreted in the urine
Glomerular filtration, is not
The amount of creatinine produced is dependent on and proportional to:
an individual's body muscle mass
In a 24-hour period, for healthy individuals creatinine is produced and excreted at:
a constant rate w/ little variance
True or False: Creatinine concentrations can be influenced by diet, hydration, or protein metabolism
False, creatinine concentrations are not influenced by diet, hydration, or protein
Elevated creatinine levels are a good indication of which condition?
Renal or kidney disease
The creatinine levels in combination w/ the ______ has been used to differentiate between:
BUN, Prerenal and renal causes of azotemia
Elevated levels of urea in the blood is termed ________
What is the principle used behind the reaction of the Creatinine Clearance test?
Factors that affect creatinine include:
age, sex, drugs, exercise, muscle mass, meat intake
Sources of error for the creatinine clearance test include:
-Non-creatinine chromogens elevate results
-Excessive heat and pH elevate results
-Improper urine collection
-Entire volume not collected
Creatinine Clearance Test calculations require both _____ and ______ values
serum and urine
What are the specimen requirements for a creatinine clearance test?
-24hour urine, timing crucial
-volume measured in ml
-one serum specimen required
What is the creatinine clearance formula? What does each part represent?
U/S X V/1440 X 1.73/SA
U = Urine creatinine concentration mg/dl
V = 24 hour volume in ml
S = serum concentration mg/dl
1440 = number of min in 24 hrs
1.73 = body surface of adult
SA = patients body surface using chart
Clearance is measured in which units?
These tests measure how much of a specific substance is being retained in the blood by the kidneys
What is the specimen of choice for retention tests?
The major end product of protein metabolism, derived principally from the amine groups of amino acids
The principal site of urea synthesis is the _____ and it is excreted by the ______
If a patient has a decreased BUN it is indicative of which condition?
If a patient has an increased BUN it is indicative of which condition?
BUN stands for:
Blood Urea Nitrogen
What is the specimen of choice for the BUN test (a retention test)?
Term used to refer to an increase in the plasma concentration of non-protein nitrogen compounds such as urea, uric acid, and creatinine
Which portion of the urea molecule does the BUN test, test for?
Increases in nitrogen compounds as measured by urea levels, may be due to ________ (______), ______________ (_______), or _________(_________)
Pre-renal (before kidney), renal (kidney) or post-renal (after kidney) causes
Factors that may cause increase in BUN levels may be water depletion, increased protein breakdown, high protein diet, inadequate blood flow to the kidneys, reduced filtration, and heart failure
Factor that increases BUN are reduced glomerular filtration due to acute or chronic renal disease
Factors that increase BUN levels include all types of urinary tract obstruction such as renal stones, tumors, or an enlarged prostate gland
Are decreased BUN concentrations a frequently seen condition?
Factors that can influence Urea Nitrogen levels include:
gender, age, diet, renal function
Sources of error for the BUN procedure include:
-Unpreserved urine, bacteria convert urea to ammonia
Most urine chemistries requires which type of specimen?
24 hour urine specimen
the principle Chemstries that are performed on urine include:
protein, electrolytes, and glucose
Increase urea levels
Increased urea levels can result from:
-High protein diet
-Reduced renal perfusion
Decrease urea levels can result from:
-Naturally occuring, liver disease
What may be done to prevent false decrease in BUN if a preservative is needed?
Preserve w/ HCl or toluene
What specimen should be used for a electrolyte testing?
First morning or random
What technology is used to test for electrolytes?
What specimen is used for glucose (urine chemistries) testing?
An enzyme that catalyzes the breakdown of starch and glycogen
Elevated amylase in urine can be seen due to:
Semen analysis is usually requested by the provider for: (3)
post-vasectomy cases, infertility studies, medico-legal cases
Semen is composed of fluid from four different areas of the body including what? what percentage?
Bulbourethral glands (5%)
Testis and Epididymus
Seminal Vesicles (60%)
Collection methods for semen analysis include:
Use of condom that has been washed (Not for fertility studies)
Before collection of semen for analysis, the patient must abstain from sexual contact for at least how many days?
Specimens should be collected in a sterile, labled container for semen analysis. True or False
Semen samples must be delivered to the lab w/ in _____ of collection and kept @ _____
30 min, 35-37C
When recording time for semen samples it is important to record:
The time the specimen was collected, not received
Fresh semen is usually collected clotted and should liquify w/in:
Liquification of longer than 60 minutes is ______ for semen
Macroscopic semen analysis is to include:
volume, viscosity, appearance, and pH
A normal viscosity is shown as semen is poured:
poured in droplets, not clumpy or stringy
Increased viscosity or incomplete liquification can interfere w/ what?
Normal volume for semen is:
Normal pH for semen is:
Which enzyme causes semen to liquefy?
All semen sample must _______ before determining viscosity.
Normal values for sperm counts are:
The dilution factor for semen analysis is _____ using a diluting fluid that consists of:
1:20, sodium bicarbonate, formalin, DI water
How long is a semen sample shook to mix the semen and diluent?
How long is the charged hemacytometer let sit in a moist petri dish to allow the spermatozoa to settle?
How many and which squares are counted on the hemacytometer for a sperm count?
4 corner squares
What is the calculation for a sperm count?
avg # sperm counted x dilution factor x 1000 = million sperm/mL
Sperm motility is performed before or after liquification of semen?
Which microscope objective is used to read a sperm count and motility?
Sperm motility observation is recorded by the percent of sperm demonstrating __________
Directional motility is the percent of sperm moving in a ___________
How many HPFs are observed when determining sperm motility?
A minimum motility of _____ and a quality of _____is considered normal w/ in ______ of collection
50-60%, fair, 3 hours
Semen analysis is determined by:
macroscopic, sperm count, sperm motility, sperm morphology and other additional tests
When observing sperm morphology @ least how many sperm should be evaluated?
If abnormal sperm morphology exceeds 10% following a sperm count:
a semen smear is prepared and stained
Sperm morphology should be reported from a _____ specimen under which objective?
stained, oil immersion
Stains that can be used for sperm morphology stains include:
Wright's, Giemsa, or Papanicolaou
The most common additonal tests that may need to be performed on abnormal semen analysis are?
sperm viability, seminal fluid fructose level, and sperm agglutinins
Explain post vasectomy semen analysis.
Looking for presence or absence of sperm. Tested until 2 consecutive specimens have no sperm seen. Results reported as 'no spermatozoa seen' OR 'spermatozoa seen'
What is the purpose of a Nasal Eosinophil Smear?
to diagnose allergic rhinitis
an infection of the nasal mucous membranes due to allergies characterized by increased percent of eosinophils in nasal secretions
Collection methods that are acceptable for a nasal eosinophil smear include:
Sneezing/Blowing Nose into waxed paper, cellophane, parafilm; Cotton tipped applicator; Aspiration of nasal secretions w/ a bulb
The three stains that are acceptable for nasal eosinophil smears are:
Wright's, Hansel's, and Eosin w/ methylene blue
Explain the evaluation of the smear of a nasal eosinophil.
-Low power first- EOs and WBCs
- Oil immersion next- scan @ least 10 fields, counting all EOs and WBCs
What is the formula to find the percentage of nasal eosinophils?
total # eosinophils counted x 100/total WBCs counted = % eosinophils
Normal eosinophils range from: _____ and a percentage greater than ____ is indicative of _____
3-10%, 10%, allergic rhinitis
Does the absence of eosinophils in a nasal smear rule out allergic rhinitis?
No, there may be a secondary sinus infection or there may have been no recent exposure to the causative agent
a clear, colorless ultra-filtrate of blood that fills the space w/in and around the CNS
What aer the functions of the CSF?
-Supplies nutrients to nervous tissue
-Removes metabolic waste
-Cushions the brain and spinal cord against trauma
How many mls of CSF are produced ever hour? total volume of adults? neonates?
20 mls, 140-170 mls, 10-60 mls
a vascular fringe-like fold of the pia mater located in the third, fourth, and lateral ventricles of the brain; where CSF is formed; has membranes that are semipermeable selective filters; acts as a blood brain barrier
Small cavities w/ in the brain
How is CSF collected? by whom?
Collected by lumbar puncture between the 3rd and 4th, or the 4th and 5th lumbar vertebrae by the physician
Three connective tissue membranes that line the brain and spinal cord
Meninge: outer layer that ines the skull and vertebral canal
Meninge: Middle layer that forms a loose brain covereing
The arachnoid and the dura mater is seperated by:
the subdural space
The arachnoid and the pia mater are seperated by the:
Meninge: delicate connective tissue w/ tiny blood vessels and is the only meninge attached to the brain
Where is the CSF contained in the brain?
What are the functions of the meninges?
-Protect blood vessels and close venous sinuses
-Form paritions w/ in the skull
How long does it take to replace the total volume of CSF?
In adults, how much spinal fluid will be obtained from the lumbar puncture? infants?
5-10 mL, 0.5-1 mL
Any leftover fluid obtained by a lumbar puncture is stored. How?
In a refigerator or freezer for 7-10 days
How many tubes of CSF are drawn and where do they get sent?
3; Tube1-Chem and Sero, Tube 2- Micro, Tube 3- Hematology
The most frequently performed chemical test on CSF is
After centrifugation, which part of the CSF is used to perform chemistry studies?
What is the only chemical found in great concentrations in CSF than in blood?
What is the most common method of protein fractions in CSF?
In protein fraction CSF, electrophoresis method uses _____ as its medium of choice followed by staining w/ ______
agarose gel, Coomassie blue
This can be seen on agarose gel in _____ of patients w/ multiple sclerosis when evaluating CSF protein fractions
95%, Oligoclonal banding
Elevated CSF protein can be cause by:
Low CSF protein can be caused by:
Meningitis and hemorrhage
Leaking from the CNS
CSF glucose should be approximately _______ of the patient's plasma glucose level.
A blood glucose should be tested how long before collecting CSF glucose?
Why should CSF glucose be processed immediately?
Glycolysis occurs rapidly in CSF
Increased CSF glucose is seen in:
plasma glucose values increased, diabetic coma
Bacterial meningitis, Insulin shock
An increase in CSF glucose is ALWAYS a result of what?
increased plasma glucose values
What is the purpose of microbiology when dealing w/ CSF?
Microbiology tests are performed on which part of the CSF?
How long must the CSF be centrifuged before staining?
15 min/ 1500 rpm
CSF culture is not an diagnostic test for meningitis, as much as it is a _________
Due to the small number of organisms that may be present in the CSF, this should be done to prevent false negatives
A false positive CSF Gram Stain may occur when:
precipitate and debris are confused for organisms
Acid Fast Stain is used to detect:
India Ink prep is used to detect:
Cryptococcus spp. (fungal meningitis)
Counter-immunoelectrophoresis is used to detect:
-Group B. Strep
Latex agglutination is used to detect:
-Group B strep
-H. influenzae type B
-E. coli k1 antigens
-Cryptococcus neoformans in serum and CSF, more sensitive than India Ink
--False pos- interference w/ rheumatoid factor
Which part of the CSF specimen is used for hematological testing?
a WELL MIXED specimen
For hematology, the appearance of CSF is examined for _____, _____, and ________. Normal spinal fluid should be _____, ______, and contain _______. Cell counts and diffs are also done.
color, appearance, clot formation
clear, colorless, no clots
Appearance of CSF in hematology:
Xanthochromic (pink, yellow, orange):
clear, colorless, like water
release of Hgb from hemolyzed RBCs; must be tested w/in one hour
Should be noted, could indicate traumatic tap or meningitis
Most blood is in tube 1, decreasing in tubes 2 and 3 indicates:
Blood will be evenly distributed in all 3 tubes will indicate:
Xanthochromic supernatant indicates:
blood was not caused by traumatic tap