Urinalysis Flashcards
What does anuria mean?
no urine output
What does oliguria mean?
less than 500 mL/day
What does nocturia mean?
greater than 500 mL/night (not to be confused with nocturnal frequency)
What does polyuria mean?
greater than 2L/day (not necessarily abnormal if someone is really hydrating themselves)
How often do children urinate compared to adults?
3-4x the volume of an adult per kg of body weight
What are the 3 descriptors of abnormal urination?
frequency
urgency
dysuria
Is urine odor part of urinalysis?
No
How is urine order normally described?
Faintly aromatic- due to presence of volatile acids
What could caused abnormal urine aroma?
Vitamins Drugs Foods (ex: asparagus) Metabolic disorders (diabetes) Bacterial contamination
What does CCMS stand for?
Clean Catch Midstream Specimen
What is the reason for CCMS
To avoid contamination of the voided specimen by organisms in areas adjacent to the urethral meatus and harbored in the distal urethra
For a urine sample collection are males or females instructed to cleanse the area 3x with separate towelettes?
Females
When is the best time to collect urine? Why?
First morning urination
- most concentrated
- bladder incubated
- best for specific gravity, nitrite, protein, and microscopic examination of the urine sediment
What is the most convenient and commonly used timing of urine collection?
Random specimen
Why would you do a 24hr specimen collection?
This is necessary for quantification of various analytes
- protein, calcium, hormones & their metabolites
When should the urine be analyzed after the collection?
Within one hour
Why should the urinalysis be done within an hour of the collection?
To avoid deterioration of:
- formed elements (casts & WBCs)
- bilirubin & urobilinogen (will decompose when exposed to light)
- glucose (metabolized by bacteria & blood cells)
- ketones (evaporate)
What do you do if you can’t do the urinalysis directly after the collection?
Refrigerate or use a preservative to prevent bacterial overgrowth
When doing an urinalysis, do you document the color and appearance of the urine?
Yes
_____ reagent strip results exceed the quantities which are normally present in urine
Positive
What are the 10 factors that are tested during the chemical examination of a urnialysis?
pH specific gravity protein glucose ketones urobilinogen bilirubin leukocyte esterase nitrite blood (hemoglobin)
What are the 7 factors that are tested during the microscopic examination of a urinalysis?
RBCs WBCs Epithelial cells Crystals Casts Micro-organisms Amorphous sediment
What is considered normal for color of urine?
Colorless to amber yellow
What could cause colorless urine?
- random specimen
- decreased renal function
What could cause dark yellow urine?
- concentrated urine- due to dehydration
- bilirubin- hepatobiliary
What could cause red urine?
- blood- urinary tract bleeding
- hemoglobin- intravascular hemolysis
- food dyes- strawberry twizzler overdose
- beets- healthy diet
What could cause brown urine?
- acid hematin- blood/hgb
- bilirubin- hepatobiliary
What are the 3 words used to describe appearance of urine?
Hazy
Cloudy
Milky
What are the formed element that cause a hazy/cloudy/or milky urine? (8)
Amorphous sediment Epithelial cells RBCs & WBCs Micro-organisms Crystals Spermatozoa WBC casts & WBC clumps Fat (chyluria)
What is a normal urine pH?
4-8
ideally 6
What causes acidic urine?
normal “western” diet
ketosis
systemic acidosis
What causes alkaline urine?
Vegetarian/vegan diet/ high level of citrus fruit
Postprandial specimen (“alkaline tide”)
Stale/unrefrigerated specimen
Urinary tract infection
What is normal for specific gravity of urine?
1.005-1.035
What is specific gravity used to evaluate?
The concentrating and excretory power of the kidneys
How would a true kidney function test be standardized?
Water deprivation for 16 hours prior to test
Why is first morning specimen more ideal than random specimen?
Because first morning specimen will be concentrated, where as random specimens will tend to be more dilute
What could cause the urine to be more concentrated?
- decreased fluid intake
- first morning specimen
- solutes in the urine such as glucose & ketones
What types of protein can show up in urine? (6)
- Albumin
- Globulins
- Hemoglobin
- Fibrinogen
- Nucleoproteins
- Bence Jones protein (paraproteins)
Which type of protein is the most common & significant health concern?
Albumin
If albumin is found in urine, what could this indicate?
Kidney pathology
- especially glomerular damage, results in albumin escaping from the plasma into filtrate
What does functional proteinuria mean?
This is proteinuria associated with fever, exposure to extreme temps, excessive exercise, or emotional stress. Tends to be minimal amounts (less than 500mg/day) of protein lost.
What is organic proteinuria?
Proteinuria associated with demonstrable systemic disease or renal damage & often results in greater than 500mg/day of protein loss.
Is there more protein lost with organic or functional proteinuria?
Organic
What are the 3 categories of proteinuria sites of origin?
- pre-renal
- renal
- post-renal
What are the 3 categories of proteinuria according to quantity lost per day?
- minimal (less than 0.5)
- moderate (0.5- 4.0)
- marked (greater than 4.0 gm)
What are some cause of minimal proteinuria?
- vigorous exercise in healthy people
- severe emotional or thermal stress
- postural/orthostatic proteinuria
- pregnancy
- early affects of kidney dysfunction
- lower UTI
What are some causes of moderate proteinuria?
- chronic glomerulonephritis
- pyelonephritis
- diabetic nephropathy
- multiple myeloma]
- pre-eclampsia
what are some causes of marked proteinuria?
- acute & chronic glomerulonephritis
- diabetic nephropathy
- nephrotic syndrome & nephrosis
- lupus nephritis
What conditions might you suspect when finding glucosuria with hyperglycemia?
- endocrine disorders
- -> diabetes mellitus
- -> cushing’s syndrome
- -> thyrotoxicosis
- exocrine pancreatic disease
- drug associated (steroids)
What conditions might you suspect when finding glucosuria without hyperglycemia?
- renal tubular disease
- late (normal) pregnancy
If ketones in urine are reported normal what does that mean?
This means that there are no ketones detected in urine= normal
What might cause ketones to be detected in urine?
- inadequate carbs in diet
- -> successful weight loss diet
- -> malnutrition
- -> defect in carb metabolism
- -> diabetes mellitus
- defect in carb absorption
Is it normal to find bilirubin in urine?
NO
Bilirubin is a catabolite of _____, and urobilinogen is a catabolite of _________.
- heme
- bilirubin
What are some causes of bilirubinuria?
- intrahepatic obstruction (ex: hepatitis)
- extrahepatic obstruction (ex: stone in common duct)
What type of bilirubin is excreted by the kidney?
ONLY CONJUGATED bilirubin
What is observed when someone has bilirubinuria? What is this associated with?
Conjugated hyperbiliruinemia
associated with hepatobiliary pathologies
What could lead to increased urinary urobilinogen?
- hemolytic diseases
- hepatic diseases
What could lead to decreased urinary urobilinogen?
- biliary obstruction
What is leukocyte esterase?
Cytoplasmic enzyme of neutrophils.
For leukocyte esterase what would cause the reagent strip to turn positive?
- significant numbers of WBCs, either lysed or intact
What can leukocyte esterase detected indicate?
UTI (very sensitive for this)
Vaginal contamination
Conditions causing heavy mucus discharge & irritation as with Trichomonas infestation
What are 3 causes of pyuria?
- inflammation within urinary tract
- infection within the urinary tract
- sterile pyuria (WBCs with negative bacteriologic evaluation)
What are some infective causes of sterile pyuria?
- viruses
- fungi
- atypical or fastidious organisms (ex: chlamydia)
What are some non-infective causes of sterile pyuria?
- systemic & localized diseases (ex: malignant hypertension, systemic inflammatory disease)
- structural & physiological abnormalities of GU tract (ex: stones, polycystic kidneys)
- certain drug treatments
- recent antibiotic treatment
What could nitrite in urine indicate?
UTI- very specific indicator of this, but lacks sensitivity
Will RBCs or hemoglobin turn a reagent strip positive?
Yes
What is hemoglobin uria?
the presence of hemoglobin in the urine with the origin being from the circulation (ie. intravascular hemolysis)
With hemoglobinuria would RBCs be seen in the urinalysis?
No
What is hematuria?
the presence of RBCs in the urine (exceeding normal) which are leaking into the urinary tract (ex: kidney through urethra)
What does isolated hematuria refer to?
Hematuria without casts or proteinuria
What does nephronal hematuria refer to?
Hematuria with casts and proteinuria
What are examples of conditions in which you might see isolated hematuria?
- normal individuals (menstrual contamination, following vigrorous exercise)
- trauma to urinary tract
- lower urinary tract infections (cystitis)
- hypertension
- bleeding disorders
- kidney pathology (stones, tumors)
What are examples of conditions in which you might see nephronal hematuria?
- acute glomerulonephritis
- chronic glomerulonephritis
- rheumatoid diseases
How might ascorbic acid affect urinalysis?
- adequate amounts may cause reduced positives or false negatives for blood, leukocyte esterase, glucose, nitirite, urobilinogen, and bilirubin
During microscopic examination of urine, what does the low power field allow you to visualize?
- amorphous sediment
- epithelial cells
- casts
- crystals
During microscopic examination of urine, what does high power field allow you to visualize?
- bacteria
- blood cells (RBCs & WBCs)
What could clumps of WBCs mean when seen in the urine?
- could indicate kidney or bladder infection- but symptoms must guide you
On high power field what is the normal number of blood cells visualized?
RBCs= 0-4/hpf WBCs= 0-4/hpf
If squamous epithelial cells are found in urine sample, what may this indicate?
- urine not collected via CCMS technique- especially in women
- could be from distal urethra &/or female vulva
Where are transitional epithelial cells found within the urinary tract?
- renal pelvis to proximal urethra
What are increased number of transitional epithelial cells found in urine indicative of?
Conditions of the bladder, such as infection or malignancy
What might be an indicator of bladder cancer?
Morphologically abnormal urothelium= large number of transitional epithelia exhibition unusual morphology
Where are renal tubule epithelial cells derived from?
- nephron to collecting tubules
What do increased numbers of renal tubule epithelia indicate?
Tubular necrosis
Tubular damage in variety of renal tubular disorders
For both transitional epithelia & renal tubule epithelia could be considered normal for these cells to be found in urine?
Yes- but it’s when there are increased numbers of either that there is an indication of pathology.
What are the most common crystals found in urine?
calcium oxalate, uric acid, and triple phosphate
When is the finding of crystals in urine clinically significant?
When the crystals appear in acidic or (occasionally) neutral pH urine
What is the finding of calcium oxalate crystals in acidic urine associated with?
- diet rich in oxalic acid
- may be calcium urinary stones
- may be hypercalcemia (could be from hyperparathyroidism)
- ingestion of high doses of ascorbic acid in certain individuals
- may be in neutral pH; rarely in slightly alkaline
What is the finding of uric acid crystals in acidic urine associated with?
- from dietary origin from foods rich in purine
- acute febrile episodes
- patients with hyperuricemia
( gout, leukemia, cancer patients with chemotherapy)
Which types of crystals are more likely to be found in acidic urine? (low pH)
Calcium oxalate crystals
Uric acid crystals
What crystals are more likely to be found in neutral or alkaline urine?
Triple phosphate crystals
What are triple phosphate crystals found in urine indicative of?
- this is considered clinically normal
What are 2 types of amorphous sediment, and what is the clinical significance of this sediment in urine?
- Urates
- Phosphates
- No clinical significance
When are urates observed in urine?
- acid pH urine
When are phosphates observed in urine?
- alkaline pH urine
What is the most commonly observed urinary cast?
Hyaline cast
What does a hyaline cast consist of?
- Tamm-Horsfall protein (a normal secretion within the tubules)
- IgA
When found alone, what does the finding of a hyaline cast indicate?
Nothing- clinically significant when found without other casts
With what types of conditions might you see hyaline casts?
- glomerulonephritis
- pyelonephritis
- chronic renal disease
What might cause someone to have an increased number of hyaline casts?
- following strenuous exercise
- dehydration
- heat exposure
- emotional stress
True or False. Finding just one RBC cast in a urinalysis is nothing to worry about.
False- this is very significant
What is an RBC cast indicative of?
- associated with glomerulonephritis
an acute inflammatory process within the kidney
What happens to an RBC cast if there is a significant delay between formation and appearance in the urine?
It breaks down into a hemoglobin cast
If an RBC cast breaks down into a hemoglobin cast, what can this indicate?
- significant stasis of filtrate flow
- this would look like a homogenous appearing red colored cast without distinct cells observed within the protein matrix
What is the presence of a WBC cast in urine indicative of?
- most often associated with pyelonephritis
- even just one is very important clinically
What type of cast will form when tubular epithelium is damaged due to a variety of glomerular and tubular conditions?
- epithelial cast
What type of cast is a disintegrated white cell cast or epithelial cast?
Granular cast- either coarsely or finely granular
- could also be a waxy cast- more advanced stages of disintegration
Which type of cast requires significant urine stasis within the tubules in order to form?
Granular cast
Which type of cast is the most advanced stage of disintegrating cellular cast?
Waxy cast
What type of cast signals existing or impending renal failure?
Waxy cast
With what condition will there be very wide (broad) casts?
Chronic Kidney disease
A broad cast is a form of what other type of cast?
Waxy
Where do broad casts form?
Collecting tubules
Where are all types of urinary casts formed?
ONLY IN THE KIDNEYS
What 3 types of microorganisms can be found in urine?
- bacteria
- yeast
- protozoa
What might increased numbers of bacteria (in the absence of squamous epithelium) indicate?
Urinary tract infection
- especially if accompanied by pyuria
If bacteria is found in urine and you suspect a UTI, what are the next necessary steps to take?
a urine culture & sensitivity
- identify to bug
- colony count
- sensitivity
What conditions might cause yeast to be found in urine?
- diabetics
- patients taking prolonged antibiotics
- estrogens for ERT or OCA
- NOT a UTI
- mainly women with vaginal yeast infection
What is the most common protozoa observed in urinalysis?
Trichomonas vaginalis
What is the certain consideration to diagnose trichomonas vaginalis via urinalysis?
Requires freshly voided warm urine sample
What is the clinical significance to finding spermatozoa in either a male or females urine?
None
What might increased amount of mucus found in a females urine indicate?
vaginal contamination
- may be some inflammation within the urinary tract
What does mucus in urine appear like?
thread-like material- may be reported as mucus threads
