Urinalysis Flashcards
Q: What is the importance of urinalysis in urological patients?
A: Urinalysis is a fundamental test that should be performed on all urologic patients as it helps assess various conditions and detect abnormalities.
Q: How should urinary specimens be collected in male patients?
A: In male patients, a midstream urine sample is typically obtained for urinalysis.
Q: How should urinary specimens be collected in female patients?
A: In female patients, a clean-catch midstream urine sample is harder to obtain. If an infection is suspected, a catheterized urine sample should be used.
Q: What is the preferred method of urine collection in neonates and infants?
A: A sterile plastic bag with an adhesive collar can be used, but the best method is percutaneous suprapubic aspiration of urine.
Q: What physical characteristics of urine are examined in urinalysis?
A:
1. Color
2. Turbidity
3. Specific gravity
4. Osmolality
5. pH
Q: What causes the pale yellow color of normal urine?
A: The normal pale yellow color of urine is due to the presence of the pigment urochrome.
Q: What is the normal appearance of freshly voided urine?
A: Freshly voided urine is usually clear.
Q: What is the normal range for specific gravity in urine?
A: The specific gravity of normal urine ranges from 1.001 to 1.035.
Q: What is the normal osmolality of urine?
A: The osmolality of urine usually varies between 50 and 1200 mOsm/L.
Q: What is the normal pH range of urine?
A: The normal urinary pH varies from 4.5 to 8.
Q: What substances are commonly tested for using urine dipsticks?
A:
1. Blood
2. Protein
3. Glucose
4. Ketones
5. Urobilinogen and bilirubin
6. White blood cells (WBCs)
Q: What is considered a normal level of red blood cells (RBCs) in urine?
A: Normal urine contains fewer than three red blood cells per high-power field (HPF).
Q: What conditions can a positive dipstick for blood in urine indicate?
A: A positive dipstick for blood in the urine can indicate hematuria, hemoglobinuria, or myoglobinuria.
Q: What is proteinuria, and how much protein is normally excreted in urine?
A: Proteinuria is the presence of excess protein in urine. Healthy adults normally excrete 80 to 150 mg of protein daily.
Q: What types of proteins are found in normal urine?
A: Normal urine protein consists of:
- 30% albumin
- 30% serum globulins
- 40% tissue proteins (mostly Tamm-Horsfall protein)
Q: What are the three types of proteinuria?
A:
1. Glomerular proteinuria: Caused by increased glomerular capillary permeability.
2. Tubular proteinuria: Due to failure to reabsorb normally filtered proteins.
3. Overflow proteinuria: Caused by an increased plasma concentration of low-molecular-weight proteins (e.g., multiple myeloma).
Q: How is abnormal proteinuria detected and confirmed?
A: Abnormal proteinuria is first detected with a dipstick test impregnated with tetrabromophenol blue dye. If positive, it is confirmed by a 24-hour urinary collection.
Q: At what blood glucose level does glucose start appearing in urine?
A: Glucose appears in urine when the serum glucose level exceeds 180 mg/dL, also known as the renal threshold.
Q: What do leukocyte esterase and nitrite tests indicate in urine?
A:
- Leukocyte esterase indicates the presence of white blood cells, suggesting infection or inflammation.
- Nitrite in urine is strongly suggestive of bacteriuria.
Q: How is urine sediment prepared for microscopic examination?
A:
1. A midstream urine specimen is obtained.
2. 10-15 mL of urine is centrifuged for 5 minutes at 3000 rpm.
3. The supernatant is poured off, and the sediment is resuspended.
4. The sediment is placed on a microscope slide for examination.
Q: What are the main elements examined in urinary sediment?
A:
1. Cells
2. Casts
3. Crystals
4. Bacteria
5. Yeast
6. Parasites
Q: What types of cells are commonly found in urine sediment?
A:
1. Erythrocytes (RBCs)
2. Leukocytes (WBCs)
3. Epithelial cells (transitional and squamous)
Q: What are the different types of casts found in urine?
A:
1. Hyaline casts: Contain only mucoproteins, may not have pathological significance.
2. RBC casts: Indicate glomerular bleeding (e.g., glomerulonephritis).
3. WBC casts: Seen in glomerulonephritis, pyelonephritis, and tubulointerstitial nephritis.
4. Granular and waxy casts: Result from degeneration of cellular elements.
5. Fatty casts: Found in nephrotic syndrome and lipiduria.
Q: What types of crystals are found in urine?
A:
- Acidic urine: Calcium oxalate, uric acid, and cystine crystals.
- Alkaline urine: Calcium phosphate and triple-phosphate (struvite) crystals.
Q: What are some important types of bacteria, yeast, and parasites found in urine?
A:
- Bacteria: Gram-negative rods (e.g., E. coli), streptococci, and staphylococci.
- Yeast: Candida albicans is the most common yeast in urine.
- Parasites: Trichomonas vaginalis and Schistosoma haematobium.
Q: What does the presence of Trichomonas vaginalis in urine indicate?
A: Trichomonas vaginalis is a frequent cause of vaginitis in women and can occasionally cause urethritis in men.
Q: What is the significance of Schistosoma haematobium in urine?
A: Schistosoma haematobium is a parasite that causes urinary schistosomiasis, and its ova can be identified in urine by their characteristic terminal spine.
