Urinalysis: Specimen Preservation

Question 1

What should you do to get the most accurate test results? (4)

Answer 1

1. Examine ASAP to eliminate effects of chemical and cellular changes
2. If not examined within one hour, refrigerate or chemically preserve
3. May be refrigerated up to 6 hours without affecting results
4. Must be warmed up to room temp for SG (specific gravity)

Question 2

What are the changes that occur as urine samples stand at room temp? (7)

Answer 2

1. RBC ↓
2. pH ↑
3. Bacterial ↑
4. Sample turbidity ↑
5. Crystals ↑
6. Casts ↓
7. Glucose ↓

Question 3

What causes an increase in pH?

Answer 3

due to bacterial breakdown of urea to ammonia