Chp. 3 Intro to Urine

What is urine?

Ultrafiltrate of plasma

How many plasma does kidney convert to filtered plasma?

170,000mL

Averge daily urine output

1200mL

Urine composition

95% water and 5% solutes

Solute variation (4)

• Diet

• Activity

• metabolism

• Endocrine functions

What is the major organic solute?

Urea

What are the major inorfanic solute (3)

• Chloride

• Sodium

• Potassium

What determines urine volume? (2)

• Hydration status

• ADH, excretion of large amounts of solids

What is the normal range of urine discharge per day?

600 - 2000mL

What is oliguria? (definition, criteria, cause)

• Decrease in urine output

• <400mL/day in adults

• Vomiting, diarrhea, severe burns

What is nocturia? (definition, criteria, cause)

• Increased urine excretion at night

• 2-3 times more excretion at night

• Hormones (cortisol)

What is polyuria? (definition, criteria, cause)

• Increased urine excretion overall

• >2.5L/day in adults

• Diabetes, psychological

Diabetes mellitus (urine volume, cause, psychological, SG)

• Increase volume

• excrete excess glucose (no reabsroption form the filtrate)

• Polydipsia

• High SG

Diabetes insipidus (urine volume, cause, psychological, SG)

• Decrease in volume

• ADH decreased

• Polydipsia

• Low SG

Urine specimen collection requirement (container, volume)

• Clean, leak-proof containers

• minimum 12 mL for anlaysis

What information needs to be on specimen labeling? (5)

• Name

• ID number

• Date

• Time

• Requisiton form

Is it okay if the sample label is placed on the lid?

No, only on the container

Specimen rejection criteria (4)

• No label or unmatched labels and req. form

• Contamination

• QNS

• Improper transportation or preservation

Specimen handling criteria (2)

• test within 2 hours

• Refrigerate or chemically preserve if needed

What is the cause of the color being modified or darkened?

Oxidation or reduction of metabolites

What is the cause of the clarity being decreased? (2)

• Bacterial growth

• Ppt of amorphous material

What is the cause of the odor being increased

Bacterial multiplication causing breakdown of urea to ammonia

What is the cause of the pH being increased?

Breakdown of urea to ammonia by bacteria

What is the cause of the glucose being decreased? (2)

• Glycolysis

• Bacterial use

What is the cause of the ketone being decreased? (2)

• Volatilization

• Bacterial metabolism

What is the cause of the bilirubin being decreased?

Exposure to light or photooxidation

What is the cause of the urobilinogen being decreased?

Oxidation to urobilin

What is the cause of the nitrite being increased?

Multiplication of nitrate-reducing bacteria

What is the cause of the cells or casts being decreased?

Disintegration in dilute alkaline urine

What is the cause of the bacteria being increased?

Multiplciation

What is the cause of the trichomonas being decreased?

Loss of motility leading to death

How to preserve urine in routine and why? (2)

• Refrigeration at 2 to 8 degrees Celsius

• Decreases bacterial growth and metabolism

Can we perform chemical test when urine is cold?

No, urine must return to RT

What chemical preservative to use and why? (2)

• Gray top for culture (sodium fluoride)

• Inhibits urease and preserves formed elements