Urinalysis

What is urinalysis?

A screening test that provides valuable information quickly and economically through a physical, chemical, and microscopic analysis of urine.

What types of analyses are included in a urinalysis?

Macroscopic, chemical, and microscopic analysis of urine.

What is the primary reason for performing urinalysis?

To aid in the diagnosis of disease.

What should a urine specimen be labeled with?

Patient's name, another identifier, date, and time collected.

What is MSU in the context of urine collection?

Midstream urine, collected for urinalysis.

What is the preferred specimen for routine urinalysis?

Freshly voided first morning urine.

Why is first morning urine preferred for urinalysis?

It is more concentrated due to overnight retention.

What should be done to the urine specimen before analysis?

It should be examined ideally within two hours of collection.

What type of container is used for collecting urine specimens?

Clean, dry, and disposable containers with leak-resistant lids.

What minimum urine volume is generally required for routine analysis?

Approximately 12 mL.

What should be done if urine cannot be analyzed within 2 hours?

Preservatives may be used to reduce bacterial action and chemical decomposition.

What are some examples of urine preservatives?

HCl, boric acid, acetic acid, toluene, formaldehyde.

What is the normal color of urine?

Shades of yellow, including pale yellow, straw, or amber.

What does darker urine indicate?

Concentration of urine.

What is the significance of urine clarity in urinalysis?

Cloudiness may indicate something abnormal.

What can cause cloudy urine?

Amorphous sediment, crystals, bacteria, mucus, yeast, or casts.

What does a faintly aromatic odor in urine signify?

The presence of volatile acids.

What is specific gravity in relation to urine?

A measure of the amount of dissolved substances in urine.

What is the normal range for urine specific gravity?

Between 1.003 and 1.035.

What does an increased specific gravity indicate?

Increased concentration or reduced fluid intake.

What is the osmolality of urine?

A measure of the concentrating ability of the kidneys.

What is the normal urinary osmolality range?

About 500-800 mOsm/kg.

What test is commonly used for measuring urine pH?

Reagent strip tests that use indicators like methyl red and bromthymol blue.

What condition is suggested by protein presence in urine?

Renal disease or proteinuria.

What is hematuria?

The presence of red blood cells in urine.

What are common causes of hematuria?

Kidney lesions, urinary tract bleeding, kidney stones.

What is a common indicator of kidney damage in urine tests?

The presence of free hemoglobin or myoglobin.

What does nitrite in urine indicate?

A possible urinary tract infection, particularly from certain bacteria.

What does a positive leukocyte esterase test suggest?

Infection or inflammation in the urinary tract.

What is glucosuria?

The presence of glucose in the urine, commonly associated with diabetes mellitus.

What is the renal threshold?

The blood glucose level at which glucose appears in the urine.

What metabolic condition can elevated ketones in urine indicate?

Diabetes or starvation.

What is bilirubin, and why is it significant in urine tests?

A breakdown product of RBCs, increased levels indicate liver dysfunction.

What is the normal urobilinogen level in urine?

Small amounts are typically present; excessive levels may indicate liver issues.

What does a high specific gravity indicate regarding kidney function?

It suggests the kidneys are concentrating urine effectively.

How can urine samples be affected by time and temperature?

If left at room temperature too long, urine changes composition rapidly.

What is the purpose of quality control in urinalysis?

To ensure accuracy by running normal and abnormal levels before patient samples.

What do azurophilic granules indicate in a leukocyte test?

The presence of leukocyte esterase, indicating infection.

Why might false positives occur in urine glucose tests?

Presence of bleach or strong oxidizers.

What could result in a false negative in urine ketone tests?

Improperly stored specimens—fresh voided urine should be used.

When is a pediatric specimen required for urinalysis?

When urine samples need to be collected from infants or small children.

What condition is associated with the presence of casts in urine?

Kidney disorders or damage.

What is the typical urine volume for a normal healthy adult in a 24-hour period?

1200-1500 mL.

What should urine specimens always be transported in?

Clean, dry, and properly labeled containers.

What can cause a sweet or fruity odor in urine?

The presence of ketones, commonly seen in diabetes.