Urinalysis Flashcards
(60 cards)
1
Q
Main component of Urine
A
Water
2
Q
Organic substances in urine
A
Urea, creatinine, uric acid, glucose, protein, hormones, vitamins, metabolized medications
3
Q
Non-organic substances in urine
A
Chloride
Sodium
potassium
4
Q
The steps of urinalysis
A
- Direct Visual observation: color, clarity,
quantity - Chemical Testing: Dipstick
- Microscopic anaylsis: automated or manual
5
Q
Red/brown urine indications
A
- food coloring, drugs, hemoglobin or myoglobin
6
Q
Black/borwn urine indications
A
malignant melanoma or alkaptonuria
7
Q
Turbidity causes
A
cellular material, protein, crystals
8
Q
Normal urine specific gravity value
A
1.002-1.035
9
Q
When is renal concentrating ability considered compromised?
A
If the sp gravity is NOT >1.022 after a 12 hr period without food or water, renal concentrating ability is considered compromised and the patient either has generalized renal impairment or nephrogenic diabetes insipidus. In ESRD the urine specific gravity tends toward staying at 1.010.
10
Q
Factors that affect urine volume
A
- Fluid intake
- Fluid loss from non-renal sources
- Variations in secretions of ADH
- The need to excrete increased amount of dissolved solid (ex. glucose or salts)
11
Q
Normal daily urine volume
A
1200 -1500 ml
12
Q
What is polyuria and what causes it?
A
- Polyuria: >2000ml/day
2. DM, DI, diuretics, caffeine, alcohol due to suppression of ADH
13
Q
What is oliguria and what causes it?
A
- <500 ml/day
2. Dehydration (vomiting, diarrhea, perspiration, severe burns)
14
Q
What does a urine dipstick analyze?
A
pH, protein, glucose, ketones, blood, bilirubin, urobilinogen, nitrite, leukocyte esterase, specific gravity
15
Q
Dipstick must be tested within how many hours of collection?
A
2 hours. Otherwise:
Increased: color, turbidity, pH, nitrite, bacteria, odor
Decreased: glucose, ketones, bilirubin, urobilinogen, RBCs, WBCs, casts (false negative results)
16
Q
What parameters suggest renal function problems?
A
- Specific gravity
- protein
- pH
- blood
17
Q
What parameters suggest UTI?
A
- Nitrite
2. Leukocyte esterase
18
Q
What parameters suggest problems with carbohydrate metabolism?
A
- GLucose
2. Ketones
19
Q
What parameters suggest liver function problems?
A
- Bilirubin
2. Urobilinogen
20
Q
Leukocyte Esterase: Normal result
A
- Negative. Not a quantitative test
21
Q
Leukocyte Esterase abnormal result indicates
A
- Bacterial and nonbacterial UTIs
- inflammation of the UT
- Better than nitrate bc detects presence of lysed cells
22
Q
Nitrites: Normal result
A
Negative
23
Q
Nitrites: abnormal results indicate
A
- Presence of nitrate reducing bacteria
- False negatives: nonreductase-containing bacteria, high concentrations of vitamin C, high specific gravity
- False positives: old specimens or non-clear catch, highly pigmented urine
24
Q
Urobilinogen: Normal results
A
- 0.01 to 1.0
25
Urobilinogen: clinical significance
1. Helps in early detection of liver disease, liver disorders, hepatitis, cirrhosis, carcinoma
2. Hemolytic disorders: excess bilirubin being converted to urobilinogen and increased urobilinogen recirculated to the liver
26
Test values that indicate hemolytic disorders
1. Negative bilirubin
| 2. Strong positive urobilinogen
27
Protein: normal results
Normal = <10 mg/dL or 100 mg/24 hr
28
What is the most important indicator of early renal disease?
Protienuria, usually seen in dipstick tests. Albumin is the most indicative of renal problems bc it is the smallest
29
Prerenal proteinuria
1. Conditions affecting the plasma, not the kidneys
| 2. Transient increasd levels of lmw plasma proteins, acute phase reactants, exceed reabsorptive capacity
30
Prerenal Tubular disorders
1. Intravascular hemolysis
2. Muscle injury
3. Acute phase reactants
4. Multiple myeloma
31
Glomerular proteinuria causes and effects
1. Damage to the glomerular membrane: SLE: streptococcal glomerulonephritis
2. Increased pressure on the filtration mechanism: hypertension, strenuous exercise, dehydration, pregnancy (preeclampsia)
3. Up to 4 g of protein lost/day
32
Tubular proteinuria: causes and effects
1. Tubular damage
| 2. much lower levels of glomerular proteinuria
33
What causes benign glomerular proteinuria?
1. exposure to cold, exercise, dehydration, high fever
34
What causes orthostatic proteinuria?
Benign (increased pressure on renal vein)
Occurs in vertical position, disappears in horizontal position
Frequently picked up on random specimen
Empty bladder before bed
Collect specimen immediately on arising
Specimen will be negative for protein
35
What causes tubular proteinuria?
1. Tubular damage affecting reabsorptive ability: Acute tubular necrosis: Toxic substances, shock, trauma, crushing injury, heavy metals, viral infections, Fanconi syndrome (generalized proximal convoluted tubule defect)
2. AMount of protein exreteds in urine: lower than the amount of protein lost in glomerular proteinuria
36
What causes postrenal proteinuria?
1. Protein added in the lower urinary and genitourinary tract
2. Microbial infections causing inflammations and release of interstitial fluid protein
3. Menstrual contamination
4. Semen / Prostatic fluid
5. Vaginal secretions
6. Traumatic injury
37
Normal Urine pH results
Normal: 4.6-8.0 (avg. 6.0)
38
How does diet and medication affect urine pH?
1. Meat = acid pH
2. Vegetables = alkaline pH
Exception = cranberry juice
3. Medications for urinary tract infection maintain an acid pH
39
Normal blood results
1. Normal: Negative
2. False positive: menstrual contamination, oxidizing detergents
3. False negative: high levels of vitamin C
40
Hematuria clinical signs and causes
1. intact RBCs, cloudy red urine
| 2. Causes: Infectious disease, renal disorders, trauma to renal system
41
Hemoglobinuria clinical signs and causes
1. clear, red urine. Red plasma
2. Transfusion rxs, severe burns, hemolytic anemias, paroxysmal hemoglobinuria
3. Toxic to renal tubules
42
Myoglobinuria clinical signs and causes
1. Clear, red/brown urine
2. protein in muscle containing heme
3. toxic to renal tubules
4. Increased CK enzymes
43
Normal ketone results
negative
44
Causes of ketonuria
1. Primary causes: diabetes mellitus, vomiting (loss of carbs), starvation, malabsorption, dieting
45
Normal Bilirubin results
Negative
46
Abnormal bilirubin results
1. Early indicator of liver disease bc conjugated bilirubin leaks back into circulation from damaged liver
2. BIle duct obstruction: bilirubin backs up into circulation and is excreted in urine. no urobilinogen is formed
3. Hemolytic disease: increased unconjugated bilirubin = jaundice, no urine bilirubin, increased urobilinogen
47
Normal glucose results
1. Normal: <0.5
2. False positive: oxidizing detergents
3. False negative: high levels of vitamin C
48
Renal threshold for glucose
160-180 mg/dl
49
What is the major screening test for diabetes mellitus?
Urine glucose
50
Describe gestational diabetes
Placental hormones block action of insulin
High fetal glucose stresses baby’s pancreas
Result is fat baby
Mother prone to type 2 diabetes
51
What are some non-diabetic causes of glycosuria?
1. Hormonal disorders: pancreatitis, pancreatic cancer, acromegaly, Cushing’s syndrome, hyperthyroidism, pheochromocytoma
2. Tubular reabsorption disorder
3. End-stage renal disease
4. Fanconi syndrome
5. Temporary lowering of renal threshold in pregnancy
6. CNS disorders
7. Stress
8. Gestational diabetes
52
What substances are identified in a microscopic examination of urine?
```
Red blood cells (RBCs)
White blood cells (WBCs)
Epithelial cells
Casts
Bacteria
Yeast ; parasites
Mucus
Spermatozoa
Crystals
Artifacts
```
53
Clinical significance of RBCs
1. Damage to glomerular membrane or vascular injury to GI tract
2. Number of cells = extent of damage
54
Macroscopic Hematuria
Cloudy, red urine, advanced disease, trauma, acute infection, coagulation disorders
55
Microscopic Hematuria
Clear urine, early glomerular disease, malignancy, strenuous exercise, RENAL CALCULI confirmation
56
Clinical significance of WBCs
1. infections: cystitis, pyelonephritis, prostatitis, urethritis
2. Glomerulonephritis, SLE, interstitial nephritis, tumors
57
What are the most important urien epithelial cells and why
1. RTE cells are the most clinically significant urine epithelial cells; indicate tubular necrosis; fragments indicate severe destruction
2. Heavy metals, drug toxicity, hemoglobin, myoglobin, viral infections, pyelonephritis, transplant rejection, salicylate poisoning
58
What causes presence of casts in urine?
1. Incresed concentration of solutes, diminished urinary flow, acid pH
2. Hyaline casts: Protein in nature; common in athletes (1-2 nl), fever, lomerulo/pyelonephritis
3. Granular: renal disease
4. Waxy: renal failure
59
What causes crystals in urine?
1. Precipitation of urine solutes: salts, organic compounds, and medications
2. Formation based on temperature, solute concentration, and pH
3. Calcium oxalate:
Calcium most common component of renal calculi
4. Liver Disease Crystals:
Leucine, tyrosine, bilirubin
60
What microorganisms may be seen in urine?
Bacteria, yeast, trichomonas (parasite)
