Urine

• Analyzing urine has references in the drawings of cavemen and in Egyptian hieroglyphics, such as the Edwin Smith Surgical Papyrus
• Basic observations of urine

  • Color
  • Turbidity
  • Odor
  • Volume
  • Viscosity
  • Sweetness
• Hippocrates wrote a book on uroscopy in 5th BCE
• In the Middle Ages, physicians concentrated their efforts very intensively on the art of uroscopy, receiving instruction in urine examination as part of their training
• In 1140 CE, color charts had been developed that described the significance of 20 different colors
• In 1964, Frederick Dekkers discovered albuminuria by boiling urine
• In 1627, Thomas Bryant wrote a book on "pisse prophets"
• In the 17th century, the invention of the microscope led to the examination of urine sediment and development by Thomas Addis of methods for quantitating urine sediments (Addis count)

  
• In 1827, Richard Bright included urinalysis as part of the doctor's routine patient examination
• Urine composition


  95% water and 5% solutes (concentration of solutes influenced by: dietary intake, physical activity, body metabolism, endocrine functions)
• Hormones in urine


  • Aldosterone (Adrenal Cortex)
  • Antidiuretic Hormone (Posterior Pituitary Gland)
  • Erythropoietin (Kidney)
• Urine analysis


  • Monitoring wellness
  • Determination and treatment of urinary tract infections
  • Detection and monitoring progress of treatment in metabolic diseases
  • Determines the effectiveness of an administered therapy as well as checking if the patients exhibited any therapy-related complications
• Factors affecting accuracy of urine analysis results

  • Collection method
  • Container use
  • Transportation and handling of specimen
  • Timeliness of the testing

  
• Urine collection containers


  • Clear, clean, dry, leak-proof disposable containers with wide mouth and wide, flat bottom
  • Individually packaged sterile containers with secure closures for microbiologic urine studies
  • Bags with adhesive for the collection of pediatric specimens
  • Large containers for 24-hour specimens
• Transfer straw


  Has a needle and an evacuated tube holder. Urine can be sterilely transferred to tubes containing preservatives for microbiology testing and tubes with conical bottoms for sediment analysis or round bottoms for automated reagent strip testing.
• Urine is considered a biohazard substance that requires the observance of Standard precautions
• Urine collection containers


  • Disposable, non-sterile, plastic containers (capacity: 50 mL)
  • Pliable polyethylene bags with adhesive for infants
  • Large, wide-mouthed plastic containers for 24-hour urine collection
  • Sterile plastic containers for urine for bacterial culture
• Urine specimen label information

  • Patient's name
  • Identification number
  • Date and time of collection
  • Patient's age
  • Location
  • Healthcare provider's name
• Requisition form


  • Must match the information on the specimen label
  • Includes method of collection or type of specimen, possible interfering medications, and the patient's clinical information
  • The time the specimen is received in the laboratory should be recorded on the form
• Reasons for specimen rejection

  • Improperly labeled containers
  • Nonmatching labels and requisition forms
  • Specimens contaminated with feces or toilet paper
  • Containers with contaminated exteriors
  • Specimens of insufficient quantity
  • Specimens that have been improperly transported
• Specimen handling


  • Tested within 2 hours
  • Delayed testing: refrigerated or have an appropriate chemical preservative added
• Specimen preservation


  • Refrigeration at 2°C to 8°C decreases bacterial growth and metabolism
  • If urine is to be cultured, it should be refrigerated during transit and kept refrigerated until cultured up to 24 hours
  • Chemical preservatives may be added when refrigeration is impossible
• Types of urine specimens

  • Random specimen
  • First morning specimen
  • Glucose tolerance specimens
  • 24-hour (or timed) specimen
  • Catheterized specimen
  • Midstream clean-catch specimen
  • Suprapubic aspiration
  • Prostatitis specimen (three-glass collection, pre- and post-massage test, Stamey-Mears test)
  • Pediatric specimens
  • Drug specimen
• Random specimen


  Most commonly received specimen, collected at any time, but the actual time of voiding should be recorded on the container. May show erroneous results from dietary intake or physical activity just before collection.
• First morning specimen


  The ideal screening specimen, preventing false-negative pregnancy tests and for evaluating orthostatic proteinuria. A concentrated specimen, thereby assuring detection of chemicals and formed elements that may not be present in a dilute random specimen.
• Glucose tolerance specimens


  Collected to correspond with the blood samples drawn during a glucose tolerance test (GTT). Urine is tested for glucose and ketones, and the results are reported along with the blood test results as an aid to interpreting the patient's ability to metabolize a measured amount of glucose and are correlated with the renal threshold for glucose.
• 24-hour (or timed) specimen


  Measuring the exact amount of a urine chemical to produce accurate quantitative results. Many solutes exhibit diurnal variations, so 24-hour collection is required. The entire 24-hour specimen must be thoroughly mixed, and the volume accurately measured and recorded.

  
• 24-hour urine collection procedure


  1. Empty the bladder upon waking up

  2. Affix the label and write down the time and date

  3. Collect all the urine passed for the next 24 hours

  4. Refrigerate the specimen if instructed

  5. Take one last void at the end of the 24 hour collection period

  6. Seal the container and transport to the laboratory
• Catheterized specimen


  Collected under sterile conditions by passing a hollow tube (catheter) through the urethra into the bladder. The most commonly requested test is a bacterial culture.
• Midstream clean-catch specimen

  An alternative to the catheterized specimen, providing a safer, less traumatic method for obtaining urine for bacterial culture and routine urinalysis. Less contaminated by epithelial cells and bacteria.

  
• Suprapubic aspiration


  Urine may be collected by external introduction of a needle through the abdomen into the bladder. Provides a sample for bacterial culture that is completely free of extraneous contamination. Can also be used for cytologic examination.
• Prostatitis specimen collection methods

  • Three-glass collection
  • Pre- and post-massage test
  • Stamey-Mears test
• Pediatric urine specimen collection

  • Soft, clear plastic bags with hypoallergenic skin adhesive to attach to the genital area
  • Sterile specimens may be obtained by catheterization or by suprapubic aspiration
• Drug specimen collection


  • Chain of custody (COC) process to document proper sample identification from collection to receipt of results
  • Witnessed or unwitnessed collection, with temperature and color inspection to identify contaminants
• Common urine tests include routine urinalysis (UA) which screens the patient for any urinary or systematic disorders
• Dilution


  No unauthorized access to the specimen was possible
• Urine specimen collections


  May be "witnessed" or "unwitnessed"
• Witnessed specimen collection


  A same-gender collector will observe the collection of 30 to 45 mL of urine
• Urine temperature measurement


  1. Must be taken within 4 minutes from the time of collection to confirm the specimen has not been adulterated

  2. The temperature should read within the range of 32.5°C to 37.7°C
• Urine temperatures outside of the recommended range may indicate specimen contamination