Collection and Physical Examination of Urine

Urine Specimen Collection

 Use dry, leak-proof, clear, colorless container with a wide mouth

 Must be properly labeled to accept for analysis

 Patient’s name

 ID number (i.e. medical record number)

 Other identifying information (i.e. sex, date of birth, location)

 Date and time of collection

 Test order must accompany specimen to accept for analysis

 Wear gloves when handling

 Must be examined within one hours of collection (or preserved for analysis)

 Refrigeration (up to 4 hours)

Types of Urine Specimens

Midstream clean-catch

(minimizes contamination)

Routine screening, when UTI is suspected

Bacteria culture

Random

Routine Screening

No UTI suspected

Catheterized

When patient cannot void on their own;

Bacterial culture

24-hour (or timed) Quantitative chemical tests

Suprapubic aspiration

Patients with a urinary obstruction or to

obtain a sterile sample from a pediatric

patient

Changes that Occur to Unpreserved Urine:

Color Oxidation of substances

Clarity Increased turbidity due to proliferation of bacteria or precipitation of chemical

substances

Odor Increased strength due to proliferation of bacteria

pH Increases as bacteria convert urea to ammonia

Bilirubin Decreases due to photo-oxidation

Glucose Decreases due to metabolism by microorganisms

Ketones Decreases due to volatilization

Nitrite Increases due to proliferation of bacteria

Urobilinogen Decreases due to oxidation

Crystals Appears due to the cooling of the specimen

Cells and Casts Decreases due to cellular degeneration

Microorganisms Increases due to proliferation

Urine Preservatives

Refrigeration Most common; can cause crystals to

precipitate

Boric acid Preserves formed elements; interferes with

pH reading; usually used for urine culture

(gray capped tube)

Chlorhexidine Prevents bacterial growth and preserves

glucose (red/yellow capped tube)

Routine Urinalysis

1. Samples should be 15mL in volume.

2. Cultures should be performed by microbiology prior to the urinalysis.

Urine Color: Normal

 Light to dark yellow

 Due primarily to urochrome

 Uroerythrin and urobilin also contribute to color

 Uroerythrin = pink pigment

 Urobilin

◼ Oxidation product of urobilinogen

◼ Orange-brown color

Urine Color: Abnormal

Dark yellow Dehydration Strenuous exercise, first morning specimen

Amber Large amounts of urobilin Food color, medications

Orange Bilirubin Pyridium

Vitamin B complex

Foods (carrots, rhubarb)

White Pyruia, lipids, chyle Vaginal creams, phosphates

Brown/Black Bilirubin

Homogentisic acid

(alkaptonuria)

Melanin

Methemoglobin

Myoglobin

Porphyrins

Iron compounds

Medications (Chloroquine, levodopa)

Yellow-green/

Yellow-brown

Bilirubin oxidized to

biliverdin

Vitamins

Green/Blue-green Pseudomonas infection Medications: amitriptyline, methylene

blue.

Pink/Red Red blood cells

Hemoglobin

Myoglobin

Porphyrins

Beets

Medications (e.g., pyridium, methyldopa)

Menstrual Contamination