Exam 2: Review Flashcards
pH will _________ in the presence of bacteria.
increase
If the Urine is left at room temperature too long, it will give an ammonia smell produced by the bacteria which will decompose the _____.
urea
Urine creatinine concentrations are _____ times higher than plasma.
50
What three things are higher in urine that in other body fluids?
Urea, sodium, chloride
What is the physiologic SG urine range?
pH?
1.002 to 1.035
4.0 to 8.0
Urine from a healthy person contains no _______ or ________, where other body fluids do.
protein, glucose
Unpreserved urine color darkens due to _________.
oxidation
What causes decreased clarity of unpreserved urine?
Bacterial growth and precipitation of amorphous material.
What causes increased odor in unpreserved urine?
Bacterial multiplication causing breakdown of urea to ammonia
What causes increased pH in unpreserved urine?
Breakdown of urea to ammonia by urease-producing bacteria/loss of CO2
What causes decreased glucose in unpreserved urine?
Glycolysis
What are the normal pigments found in urine?
Uroerythrin and Urobilin
When is uroerythrin most evident?
when deposited on amorphous crystals in a stored urine specimen, causing a pink color or “brick dust” sediment
What are two possible causes of abnormally dark yellow urine?
-May be dehydrated
-May have high conversion of urobilinogen → urobilin
What are possible causes of amber/orange urine?
-RBC breakdown in alkaline urine
-May have bilirubin (shake and look at foam)
-Formation of urobilinogen - normal component to urine but photo oxidized and turns yellow orange. No yellow foam
-Patient maybe taking phenazopyridine to relieve symptoms of urinary tract infection
What can the foam of a urine sample indicate?
-yellow foam = may be bilirubin
-white foam = formation of urobilinogen (normal component of urine but photo oxidizes and turns yellow/orange)
What drug that is used to relieve symptoms of urinary tract infection can cause an abnormal amber/orange urine color?
phenazopyridine
What are two possible causes of pink colored urine?
-Oxidized porphobilinogen in patient with porphyria if specimen has set out too long
-Amorphous crystal formation causes a light pink color to form
What can cause a red color of urine?
RBCs, hemoglobin, beets
Three possible causes of brown/black urine?
-Myoglobin; muscle breakdown, too much is damaging to the kidney
-Oxidized melanogen in patient with malignant melanoma if specimen is set out too long
-Could also be blood or Hgb
Three possible causes of blue/green urine?
-Biliverdin
-Pseudomonas
-Propofol
What is common cause of urine color changes?
numerous drugs
What is the clinical significance of foam in urine?
-Not normally included on report forms
-Normal urine when shaken will produce white foam then rapidly dissipate
-Stable white foam indicated large amounts of albumin in urine
-Yellow foam caused by increased bilirubin
What genetic disorder can caue a Mousy odor?
PKU
What can cause a rancid odor?
Tyrosinemia
What can cause a sweaty feet odor?
isovaleric acidemia
What can cause a cabbage odor?
Methionine malabsorption
What can cause a bleach odor?
contamination
The density of a solution compared with the density of an equal volume of distilled water at the same temperature
Specific gravity
The GREATER the urine density, the _________ the specific gravity
larger
How is SG different from osmolarity?
Osmolality depends on the number of particles in the solution, while specific gravity depends on the number and weight of the solutes. Osmolality is a better indicator of concentrating and diluting abilities of the kidney
What value is isosthenuric?
1.010 (SG of plasma ultrafiltrate)
What value is hypothenuric?
hepersthenuric?
lower than 1.010
higher than 1.010
Normal random SG range?
1.003- 1.035: most common is 1.015- 1.025
What is a more representative measure of renal concentrating ability?
Osmolarity
Osmolarity is ONLY effected by…
the number of particles present
What does SG depend on?
-number of particles present AND the density (size) of the particles
Osmolarity can be determined by measuring a property that is mathematically related to the number of particles in a solution known as __________ property.
colligative
What can cause changes in colligative properties?
-Lower freezing pt
-Higher boiling pt
-Increased osmotic pressure
-Lower vapor pressure
What instrument is used to measure osmolarity?
osmometer
Automated osmometer utilizes ______________ to measure osmolarity.
freezing point depression
What are the most common causes of end stage renal disease?
-Diabetes mellitus and related diabetic nephropathy (Kimmelstiel-Wilson disease) -high blood pressure
What are 3 diseases that may produce renal tubular epithelial cells?
-Alport’s syndrome
-Acute tubular Necrosis
-Acute interstitial nephritis
Protein is present in most renal diseases due to __________ malfunction
glomerular
High levels of protein: glomerular impairment especially __________ syndrome.
nephrotic
Lower levels of protein are seen with…
tubular disorders and pyelonephritis
Chronic inability to vary the urine specific gravity and sloughed off renal tubular cells → _________ disorders
tubular
White blood cell casts usually indicate the infection is where?
in the kidneys rather than in the lower UT
What should be suspected with there is acute onset of proteinuria and hematuria with suddenly decreased GFR?
One of the acute glomerulonephritis disorders
Likely renal disease with Red blood cell casts?
Acute glomerulonephritis
Likely renal disease with White blood cell cast?
Pyelonephritis
Likely renal disease with Hyaline cast?
Strenuous activity, fever, diuretics, concentrated urine-dehydration
Likely renal disease with Renal tubular cast?
Acute tubular necrosis, interstitial nephritis
Likely renal disease with fatty casts?
Nephrotic syndrome, minimal change disease
Likely renal disease with Broad, Waxy casts?
Chronic renal disease, chronic renal failure
Likely renal disease with granular casts?
Nonspecific, often contains cells that have broken down/degenerated or contains aggregates of plasma proteins, seen more often in chronic conditions, but not exclusively
3 causes of chronic kidney disease?
-hypertension (damages vessels)
-diabetes (blood vessel damage and edema)
-obesity (increases intraglomerular pressure)
Infection of the kidney caused by the same bacteria that cause cystitis but the bacteria have ascended through the ureter to the kidney
Pyelonephritis
Pyelonephritis can be differentiated from cystitis by the presence of…
WBC casts and renal epithelial cells
-both will have many WBCs
What is seen in pyelonephritis as the disease progresses?
-granular and waxy casts
-high protein
What may be absent in chronic pyelonephritis?
bacteria and casts
Treatment of acute renal failure often leads to…
resolution
Chronic renal failure almost always goes to…
End Stage Renal Disease (ESRD)
Mortality rates are high in acute renal failure, but it is not a __________ disease like the chronic form.
progressive
What are the four stages of renal failure?
- Diminished renal reserve
- Renal insufficiency
- Renal failure
- End stage renal disease
stages of Chronic Renal Failure:
GFR drops to about 50% of normal
- Diminished renal reserve
stages of Chronic Renal Failure:
-further GFR decrease
-BUN and serum creatinine -increase (azotemia)
-Anemia
-Hypertension
- Renal insufficiency
stages of Chronic Renal Failure:
GFR <20%
Loss of urine volume and solute regulation
Acidosis
Edema
- Renal failure
stages of Chronic Renal Failure:
GFR <5%
Scarring
Tubular fibrosis
Loss of kidney mass
Dialysis and/or kidney transplant required for survival
- End stage renal disease
