Urinalysis

• Hippocrates wrote a book on uroscopy

  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
• Color charts had been developed that described the significance of 20 different colors


  1140 CE
• Frederick Dekkers discovered albuminuria by boiling urine


  1964
• Thomas Bryant wrote a book on "pisse prophets"


  1627
• 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 cells in the urine)

  
• Richard Bright included urinalysis as part of the doctor's routine patient examination

  1827
• Urine composition


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


  • Aldosterone (Adrenal Cortex)
  • Antidiuretic Hormone (Posterior Pituitary Gland)
  • Erythropoietin (Kidney)
• Purposes of urine analysis

  • Monitoring wellness
  • Determination and treatment of urinary tract infections
  • Detection and monitoring progress of treatment in metabolic diseases
  • Determination of 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 to prevent overturning
  • 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 from infants is collected using pliable polyethylene bags with adhesive
• 24-hour urine collection uses large, wide-mouthed plastic containers
• Urine for bacterial culture is collected in sterile plastic containers
• Specimen label information


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

  • Method of collection or type of specimen
  • Possible interfering medications
  • Patient's clinical information
  • Time the specimen is received in the laboratory

  
• Reasons for specimen rejection

  • Specimens in unlabeled 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 preservation


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


  Bactericidal, inhibits urease, and preserves formed elements in the sediment
• Random specimen


  Most commonly received specimen, used for routine screening tests but may show erroneous results from dietary intake or physical activity just before collection
• First morning specimen


  Ideal screening specimen, concentrated to assure detection of chemicals and formed elements that may not be present in a dilute random specimen
• Glucose tolerance specimens


  Include fasting, half-hour, 1-hour, 2-hour, and 3-hour specimens, and possibly 4-hour, 5-hour, and 6-hour specimens, tested for glucose and ketones
• 24-hour (or timed) specimen


  Measures the exact amount of a urine chemical substance, required due to diurnal variations and daily activities

  
• Sample 24-hour (timed) specimen collection procedure


  1. Provide patient with written instructions and proper collection container and preservative

  2. Patient voids and discards specimen on Day 1 at 7 a.m., collects all urine for the next 24 hours, refrigerating the specimen

  3. On Day 2 at 7 a.m., patient voids and adds this urine to previously collected urine

  4. On arrival at laboratory, the entire 24-hour specimen is thoroughly mixed, and the volume is measured and recorded
• Catheterized specimen


  Collected under sterile conditions by passing a hollow tube (catheter) through the urethra into the bladder, commonly requested for bacterial culture
• Midstream clean-catch specimen


  Provides a safer, less traumatic method for obtaining urine for bacterial culture and routine urinalysis, using mild antiseptic towelettes for cleansing
• Suprapubic aspiration


  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
• Three-glass collection for prostatitis specimen


  1. Prior to collection, the area is cleansed using the male midstream clean-catch procedure

  2. First urine passed is collected in a sterile container, then the midstream portion in another sterile container

  3. The prostate is then massaged so that prostate fluid will be passed with the remaining urine into a third sterile container

  4. Quantitative cultures are performed on all specimens, and the first and third specimens are examined microscopically
• Pre- and post-massage test for prostatitis


  A clean-catch midstream urine specimen is collected, then a second urine sample is collected after the prostate is massaged. A positive result is significant bacteruria in the post-massage specimen of greater than 10 times the pre-massage count.
• Stamey-Mears test for prostatitis


  The four-glass method consists of bacterial cultures of the initial voided urine (VB1), midstream urine (VB2), expressed prostatic secretions (EPS), and a post-prostatic massage urine specimen (VB3). Urethral infection or inflammation is tested for by the VB1, and the VB2 tests for urinary bladder infection. The prostatic secretions are cultured and examined for white blood cells.

  
• Pediatric specimen collection

  Use of soft, clear plastic bags with hypoallergenic skin adhesive. Sterile specimens may be obtained by catheterization or by suprapubic aspiration. For routine specimen analysis, ensure the area is free of contamination. For microbiology specimens, clean the area with soap and water, sterilely dry, and firmly apply a sterile bag.
• Drug specimen collection


  The chain of custody (COC) is the process that provides documentation of proper sample identification from collection to receipt of laboratory results. Proper identification of the individual is required. Urine specimen collections may be "witnessed" or "unwitnessed". If witnessed, a same-gender collector will observe the collection of 30 to 45 mL of urine, and the urine temperature must be taken within 4 minutes to confirm it has not been adulterated.

  
• Routine urinalysis (UA)


  Frequently ordered urine test that screens the patient for any urinary or systematic disorders, covering physical, chemical, and microscopic analysis
• Culture & sensitivity (C&S) urine test

  Requested if the patient has symptoms of a urinary tract infection (UTI), using a midstream clean-catch specimen placed in a sterile container. A measured portion is cultured to identify any microorganisms present and determine the most effective antibiotic for treatment.
• Urine cytology studies


  Requested to detect cancer, cytomegalovirus, and other viral and inflammatory diseases in the urinary system, using a fresh clean-catch specimen for a smear that is stained and examined under a microscope for abnormal cells.

  
• Urine drug testing


  Performed using urine to detect illicit use of recreational drugs, use of anabolic steroids, and unwarranted use of prescription drugs, as well as to monitor therapeutic drug use and confirm drug overdose.
• Urine glucose and ketone testing


  Performed to detect and monitor conditions like diabetes mellitus.