Urinalysis Flashcards
What are the types of analysis?
Types of Analysis
- Macroscopic Examination
- Chemical Analysis (Urine Dipstick)
- Microscopic Examination
- Culture (not covered in this lecture)
Components of macroscopic examination
Macroscopic Examination
- Odor/Smell
- Color
If odor is ammonia-like what does that potentially indicate?
Ammonia-like: (Urea-splitting bacteria)
If odor is foul, offensive what does that potentially indicate?
Foul, offensive: Old specimen, pus or inflammation
If odor is sweet what does that potentially indicate?
Sweet: Glucose
If odor is fruity what does that potentially indicate?
Fruity= Ketones
If odor is sulfur what does that potentially indicate?
Sulfer= Asparagus
If color is colorless what does potentially that indicate?
Colorless= Diluted urine
If color is deep yellow what does potentially that indicate?
Deep Yellow= Concentrated Urine
If color is yellow-green what does that potentially indicate?
Yellow-Green= Bilirubin / Biliverdin
If color is red what does that potentially indicate?
Red= Blood / Hemoglobin
What does a chemical analysis consist of?
Urine Dipstick
What is the range for normal specific gavity?
Normal range of specific gravity: 1.001-1.030
What is the cause of low specfic gravity (< 1.001)?
Diabetes insipidus (low SG)
What is the cause of high specific gravity (> 1.030)?
Dehydration (high SG)
What are some limitations of the urine dipstick?
Limitations of Urine Dipstick Specific Gravity
- Interference: alkaline urine
- Does not measure non-ionized solutes (e.g. glucose)
What is the normal pH for urine?
Normal pH 6
What causes urine to be acidic?
Acidic (less than 4.5):
- metabolic acidosis
- high-protein diet
What would cause urine to be basic?
Alkaline (greater than 8.0)
- renal tubular acidosis (>5.5)
What are the limitations of the urine dipstick for pH?
Limitations
- Interference: bacterial overgrowth (alkaline or acidic)
- “run over effect” effect of protein pad on pH indicator pad
- Buffers from the protein area of the strip (pH 3.0) spill over to the pH area of the strip and make the pH of the sample appear more acidic than it really is.
What are some pathological reasons for protein in the urine?
Pathological Reasons for Protein in Urine
- Glomerulonephritis
- Renal tumor
What are some causes of glucose in the urine?
Glucose
- Diabetes mellitus
- Renal glycosuria
What are some limitations of testing glucose on a urine dipstick?
Limitations
- Only measures glucose and not other sugars.
- Renal threshold must be passed in order for glucose to spill into the urine.
What are the non-pathological reasons why protein would be in urine?
Non-Pathological Reasons for Protein in Urine
- Severe muscular exertion
- Pregnancy
What are some causes of ketones in the urine?
Causes
- Diabetic ketoacidosis
- Prolonged fasting
What are the limitations of testing for ketones in urine with a urine dipstick?
Limitations
- Interference: expired reagents (degradation with exposure to moisture in air)
What are some causes for blood in the urine?
Causes
- Hematuria (nephritis, trauma, etc)
- Hemoglobinuria (hemolysis, etc)
- Myoglobinuria (rhabdomyolysis, etc)
What is the cause for nitrite in the urine?
Cause
- Gram negative bacteriuria
What are some causes for bilirubin in the urine?
Causes
- Increased direct bilirubin (correlates with urobilinogen and serum bilirubin)
- Bile or Hepatic obstructions
What are some causes for leukocyte esterase in the urine?
Causes
- Pyuria
- Acute inflammation
- Renal calculus
What are some key guidelines for urine preservation for the microscopic examination?
Preservation
- Cells and casts begin to disintegrate in 1 - 3 hrs. at room temp.
- Refrigeration for up to 48 hours (little loss of cells).
What are some general aspects for specimen concentration for microscopic examination?
Specimen concentration
- Ten to twenty-fold concentration by centrifugation.
What does the presence of erythrocyte casts indicate?
Erythrocyte Casts: Glomerular diseases
What does the presence of leukocyte casts indicate?
Leukocyte Casts: Pyuria, glomerular disease
What is the Significance of Cellular Casts?
What is a renal calcului?
Renal calcului = kidney stone
What is the diagnosis?
- Diluted urine, request a voided urine in the morning
- If persisting low SG, possible diabetes insipida
- A microscopic may give negative results
What is the diagnosis?
- Possible gallbladder or hepatic disease.
- No hemolytic anemia. Perform bilirubins in serum
- Microscopic unlikely to provide additional info
What is the diagnosis?
- Possible UTI, request culture and antibiotic sensitivity
- Negative Nitrite test: Gram positive bacteria
- Lower SG may show less number of cells and bacteria
- Un-common diagnosis in this type of patient
What is the diagnosis?
- Diabetes Mellitus
- May be decompensated and with ketoacidosis
- Ketones should become negative after treatment
What is the diagnosis?
- Glomerulonephritis
- RBC casts reveals renal cortex involvement
- RBC cast are not always present in GN
What is the diagnosis?
Acute pyelonephritis
What is the diagnosis?
Diabetes mellitus, type I
What is the diagnosis?
Nephrotic syndrome
What is the diagnosis?
Renal calculus
What is the diagnosis?
Systemic lupus erythematosus (SLE) with lupus nephritis
What is the diagnosis?
Rhabdomyolysis
What is the diagnosis?
Adult polycystic kidney disease with chronic renal failure
What is the diagnosis?
Transitional cell carcinoma of bladder
What is the diagnosis?
Factitious specimen
