AUBF LECCC Flashcards
references to the study of urine.
Edwin Smith Surgical Papyrus
Basic Observations of urine
color
turbidity
odor
volume
viscosity
sweetness
Color charts had been developed
1140 CE
Thomas Bryant published a book about
Pisse prophets
Urinalysis began to disappear.
1930
TWO UNIQUE CHARACTERISTICS OF URINE SPECIMENS
- Readily available
- Contains information on body’s metabolic function
Approximately ______ of filtered plasma is converted.
170,000 mL
FACTORS AFFECTING THE CONCENTRATION OF SOLUTES:
- Dietary intake
- Physical activity
- Body metabolism
- Endocrine function
Primary organic component
Urea
Product of creatine metabolism
Creatinine
Product of breakdown of nucleic acid
Uric acid
Primary inorganic component
Chloride
Primarily from salts
Sodium
Combined with chloride and other salts
Phosphate
Combined with sodium to buffer the blood
Phospate
Regulates blood and tissue fluid acidity
Ammonium
Normal daily urine output
1200 - 1500ml
Combines with chloride, sulfate, and phosphate
Calcium
Decreased urine output
Oliguria
Reference range for oliguria
- Infants: less than 1mL/kg/hour
- Children: less than 0.5mL/kg/hour
- Adults: less than 400 mL/day
Cessation of urine flow
Anuria
Increased urine excretion during the night
Nocturia
Increased daily urine volume
Polyuria
Reference range for polyuria
- Adults: greater than 2.5L/day
- Children: 2.5 – 3mL/kg/day
Changes in Unpreserved Urine
Breakdown of urea to ammonia/Loss of CO2
pH
Multiplication
Bacteria
Bacterial multiplication
Odor
Multiplication of nitrate-reducing bacteria
Nitrite
IDEAL URINE PRESERVATIVE:
- Bactericidal
- Preserve formed elements
- Inhibits urease
- Most commonly receive specimen
- Collected at any time
- Purpose: Routine screening
Random
- Ideal screening specimen
- Concentrated specimen
First morning
Quantitative chemical test results
24-HOUR OR TIMED SPECIMEN
Begin and end the collection period with an empty bladder.
24-HOUR OR TIMED SPECIMEN
Solutes with diurnal variations:
- Catecholamines
- 17-hydroxysteroids
- Electrolytes
Alternative to catheterized specimen
Routine screening and bacterial culture
Midstream clean-catch
Collected by the external introduction of needle
SUPRAPUBIC ASPIRATION
- 1st specimen:
First passed urine
2nd specimen
Midstream portion
3rd specimen
prostate fluid and remaining urine
Examined microscopically
1st and 3rd
Control for bladder and kidney infection
2nd specimen
Volume needed for drug testing
30-45ml
CONSIDERATIONS FOR TAMPERED SPECIMENS
- Temperature within 4 minutes of voiding: not within 32.5 - 37.7 °C
- Color: signs of contaminants
- pH: greater than 9
- Specific gravity: less than 1.005
vital bean-shaped organs located on either side of the spine, just below the ribcage.
kidney
The kidneys are composed of two main regions
- Cortex
- Medulla
is the outer layer of the kidney, containing the majority of the glomeruli, which are essential for filtering blood.
Cortex
located deeper within the kidney, consists of renal pyramids and is primarily involved in concentrating urine.
Medulla
Each kidney houses approximately (nephrons)
1 - 1.5 million nephrons
are microscopic structures that filter blood, remove waste products, and balance the body’s fluids and electrolytes.
nephrons
Comprising about 85% of the total nephrons
cortical nephrons
essential for filtering waste products from the blood and reabsorbing necessary nutrients and water back into the bloodstream.
Cortical nephrons
These nephrons are situated near the junction of the cortex and medulla, with their loops of Henle extending deep into the medulla.
Juxtamedullary
primarily responsible for the concentration of urine
Juxtamedullary
The process of filtration occurs
glomerulus
The process of reabsorption occurs in
PCT, loop of henle, DCT, collecting duct
The process of secretion occurs in
DCT, collecting duct
The process of Excretion occurs in
collecting duct, renal pelvis, ureters, bladder
Water reabsorption is regulated by
antidiuretic hormone
Water reabsorption is particularly significant
loop of Henle and collecting duct
the pigment responsible for the
yellow hue, typically ranges from pale yellow to deep amber.
urochrome
is a byproduct of endogenous metabolism and is produced at a
relatively constant rate under normal conditions.
urochrome
The journey of urochrome starts with the
breakdown of hemoglobin
hemoglobin is degraded primarily in the liver and spleen. During this
process, hemoglobin is converted into a substance called
bilirubin
is a precursor to several important substances and can be
absorbed into the bloodstream or continue its journey through the intestines.
urobilinogen
the final product of this metabolic pathway, is what gives urine its characteristic yellow color
urobilin
A pink pigment that becomes more apparent when urine is refrigerated, causing amorphous urates to precipitate.
uroerythin
An oxidation product of urobilinogen, this pigment imparts an orange-brown color to urine that is not fresh
urobilin
it can be suspected if a yellow
foam appears when the urine is shaken
presence of bilirubin
Conditions like ______ can lead to elevated bilirubin levels
hepatitis
cirrhosis,
bile duct obstruction
Medications such as used for urinary tract infections can impart a bright orange hue to the urine.
phenazopyridine (Pyridium) or azo-gantrisin
The most common cause of red, pink, or brown urine is the presence of
blood
Red or brown urine with blood may indicate bleeding in the urinary tract, such as from the
kidney, bladder, urethra
Presence of hemoglobin in the urine, often due to hemolysis or severe bleeding. Urine is red and typically cloudy
hemoglobinuria
Presence of myoglobin in the urine, often due to muscle injury or rhabdomyolysis. Urine is red but remains clear.
Myoglobinuria
Urine containing ______ may appear red, resembling the color of port wine.
porphyrins
Urine containing porphyrins can appear red due to the oxidation of
porphobilinogen
Brown or black urine that turns color upon standing may contain melanin, an oxidation product of melanogen associated with
malignant melanoma
the presence of melanin in urine
melaninuria
metabolic byproduct resulting from the breakdown of tyrosine and phenylalanine
Hemogentisic acid
an inherited metabolic disorder, homogentisic acid accumulates in the body and can cause urine to turn black, particularly when it is alkaline
alkaptonuria
The presence of homogentisic acid in urine is a key indicator of
alkaptonuria
Pathogenic causes of blue or green urine are often linked to
bacterial infections
can lead to green urine due to the production of pigments like pyocyanin and pyoverdin.
pseudomonas aeruginosa
A muscle relaxant that can cause urine discoloration.
methocarbamol
An antidepressant that can cause green urine due to its metabolites
Amitriptyline
refers to the transparency or turbidity of a urine specimen and is an essential aspect of the physical examination in urinalysis
turbidity
(COLOR)
This is typically considered normal and indicates that the urine is free from significant suspended particles.
Clear
The urine is slightly opaque, with some particles that make it difficult to see through. This may suggest the presence of small amounts of cells, crystals, or other substances
hazy
The urine is very opaque and has a muddy or murky appearance
Turbid
The urine has a thick, opaque appearance with a milky or creamy consistency. This may be due to a high concentration of lipids or other suspended substances.
milky
In acidic urine, amorphous urates precipitate and can create a pinkish appearance often described as _____ due to the
presence of uroerythrin
brick dust
Lymph fluid in the urine, known as
Chyluria
is a key parameter in urine analysis, reflecting the kidney’s ability to concentrate or dilute urine based on hydration status and renal function
Specific gravity
In a healthy individual, the specific gravity of urine can range from
approximately
1.002 - 1.035
Urine with a specific gravity below 1.010
Hyposthenuric urine
Urine with a specific gravity above 1.010
Hyperthenuric urine
is a technique used to measure the concentration of dissolved particles in a urine specimen by evaluating its refractive index.
Refractometry
Two major types of reagent strips are
Multistix, Chemstrip
Strips should be checked at least once every
24 hours
is not recommended as a negative control due to its low ionic concentration, which differs from urine.
Distilled water
in urine may mask color reactions, leading to false results.
Phenazopyridine
Care of Reagent Strips
- Store with a desiccant in an opaque, tightly closed container.
- Keep below 30°C; avoid freezing.
- Prevent exposure to volatile fumes.
- Do not use past the expiration date.
- Discard strips if the chemical pads become discolored.
- Remove strips from the container only just before use.
urine pH ranges from
4.5 - 8.0
cause the body to excrete more hydrogen ions, leading to more
acidic urine.
acidosis
Metabolic or respiratory alkalosis, where there’s an excess of base in the body
alkalosis
Methyl Red:
PH RANGE
4 - 6
This color change helps in detecting more acidic pH levels.
Methyl red (red to yellow)
Bromthymol Blue:
pH Range:
6 - 9
the pH increases, allowing the detection of more alkaline conditions.
Bromthymol blue (yellow to blue)
the presence of excess protein in
urine, is often associated with early renal disease, making the urinary protein test a crucial component of any comprehensive physical examination.
Proteinuria
The major serum protein found in urine
albumin
These are low-molecular-weight proteins found in the blood and produced by renal tubular cells.
Serum and Tubular Microglobulins
Produced by the renal tubular epithelial cells in the distal convoluted tubule
Tamm-Horsfall Protein (Uromodulin)
Clinical proteinuria is generally considered significant when protein levels reach
30 mg/dL (300 mg/L)
arises from conditions that affect the plasma before it reaches the kidneys.
Prerenal Proteinuria
This protein is typically found in patients with multiple myeloma, a type of cancer characterized by the abnormal proliferation of plasma cells, which produce excessive amounts of monoclonal immunoglobulin light chains
Bence Jones Protein
refers to the presence of excess protein in the urine due to damage within the kidneys.
Renal Proteinuria
is the presence of small amounts of albumin in the urine and is often an early sign of diabetic nephropathy, a condition where diabetes damages the kidneys.
Microalbuminuria
It occurs when protein levels in the urine increase due to prolonged standing, but levels normalize when lying down.
Orthostatic proteinuria (postural proteinuria)
the kidneys’ tubules are unable to
reabsorb proteins that were filtered through the glomeruli.
Tubular proteinuria
occurs when protein is introduced into the urine after it has left the kidneys
Postrenal proteinuria
It is useful as a secondary test when protein interference or other
issues are suspected.
SSA test
