urinalysis

• 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


  5th BCE
• 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


  1694
• Thomas Bryant wrote a book on "pisse prophets"


  1627
• 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)


  17th century
• 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)
• Specimen collection procedure

  1. Explain to patient

  2. Depends on type of test ordered

  3. Helps in monitoring wellness

  4. Helps in determination and treatment of urinary tract infections

  5. Helps in detection and monitoring progress of treatment in metabolic diseases

  6. Determines the effectiveness of an administered therapy and checks for therapy-related complications
• Factors affecting accuracy of urine analysis results

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

  
• Urine containers


  • Clear, clean, dry, leak-proof
  • Disposable
  • Wide mouth to facilitate collections from female patients
  • Wide, flat bottom to prevent overturning
  • Individually packaged sterile for microbiologic urine studies
  • Bags with adhesive for 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
• Disposable, non-sterile, plastic containers are most commonly used (capacity: 50 mL)
• Urine from infants

  Pliable polyethylene bags with adhesive
• 24-hour urine collection

  Large, wide-mouthed plastic containers are used
• Urine for bacterial culture

  Sterile plastic containers
• Labels on urine containers

  • Patient's name
  • Identification number
  • Date and time of collection
  • Additional information such as the patient's age, location and the healthcare provider's name
• 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 integrity

  • Tested within 2 hours
  • If 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
  • When refrigeration is impossible, chemical preservatives may be added
• Ideal preservative


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


  • Most commonly received
  • Collected at any time, but the actual time of voiding should be recorded
  • Used for routine screening tests
  • May show erroneous results from dietary intake or physical activity just before collection
• First morning specimen


  • Ideal screening specimen
  • Prevents 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
  • Patient should collect immediately on arising and deliver to lab within 2 hours or keep refrigerated
• Glucose tolerance specimens


  • Collected to correspond with the blood samples drawn during a glucose tolerance test
  • Urine tested for glucose and ketones, and the results are reported along with the blood test results
• 24-hour (or timed) specimen


  • Measures the exact amount of a urine chemical
  • Produces accurate quantitative results
  • Many solutes exhibit diurnal variations
  • Thoroughly mixed and the volume accurately measured and recorded
  • Refrigerated or kept on ice during the collection period and may also require addition of a chemical preservative

  
• 24-hour (timed) specimen collection procedure


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

  2. Day 1: 7 a.m. - patient voids and discards specimen, collects all urine for the next 24 hours

  3. Day 2: 7 a.m. - patient voids and adds this urine to previously collected urine

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

  
• 24-hour urine collection procedure

  1. Empty bladder upon waking up

  2. Affix label and write down time and date

  3. Collect all urine passed for next 24 hours

  4. Refrigerate specimen if instructed

  5. Avoid dehydration

  6. Take last void at end of 24 hour period

  7. Seal container and transport to lab
• Catheterized specimen


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


  • Alternative to catheterized specimen
  • Less contaminated by epithelial cells and bacteria
  • Mild antiseptic towelettes recommended for cleansing, not strong agents like hexachlorophene or povidone-iodine
• Suprapubic aspiration


  • Urine 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

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

  2. First urine passed is collected in sterile container

  3. Midstream portion collected in another sterile container

  4. Prostate is massaged so that prostate fluid will be passed with remaining urine into a third sterile container

  5. Quantitative cultures performed on all specimens, and first and third specimens examined microscopically

  
• Positive result for prostatitis

  • Third specimen will have a white blood cell/high-power field count and a bacterial count 10 times that of the first specimen
  • Macrophages containing lipids may also be present
• Pre- and post-massage test (PPMT) for prostatitis

  • Clean-catch midstream urine specimen collected before and after prostate massage
  • Positive result is significant bacteriuria in the post-massage specimen of greater than 10 times the premassage count
• Stamey-Mears test for prostatitis

  • Four-glass method consisting of bacterial cultures of initial voided urine (VB1), midstream urine (VB2), expressed prostatic secretions (EPS), and post-prostatic massage urine specimen (VB3)
  • VB1 tests for urethral infection or inflammation, VB2 tests for urinary bladder infection, and prostatic secretions are cultured and examined for white blood cells

  
• Pediatric specimen collection


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

  • Chain of custody (COC) process documents proper sample identification from collection to receipt of results
  • COC form must accompany every step of drug testing
  • Proper identification of individual is required
  • Urine specimen collections may be "witnessed" or "unwitnessed"
  • If witnessed, a same-gender collector will observe the collection and take the urine temperature within 4 minutes to confirm it has not been adulterated