urinalysis

• urinalysis is the testing of urine with procedure s commonly performed in an expiditious, reliable, accurate, safe, and cost effective manner.
• parts of routine urinalysis:

  • physical
  • chemical
  • microscopical
• edwin smith surgical papyrus contributed egyptian hieroglyphics
• hippocrates wrote uroscopy
• in 1140 CE, 20 different colors of urine color chart
• thomas bryant wrote about charlatans who compromised urinalysis without medical credentials
• richard bright introduced urinalysis as part of doctor's routine patient exam
• frederick Dekkers discovered albuminuria by boiling urine
• thomas addis quantitated urine sediments
• average urine output is 1200mL
• urine is approximately 170,000 mL filtered by plasma
• urine is the ultrafitrate of plasma
• total renal blood flow is 1200mL/min
• total renal plasma flow/filtered plasma is 120 mL/min
• every minute approximately 2-3 million glomeruli filter approximately 120 mL of water containing low molecular weight substances
• urine is 95% water and 5% solutes
• urine is composed of organic and inorganic components and is normally acidic
• all substances of the urine are all water soluble
• urea is the principal organic substance of urine
• urea is nearly half of the total dissolved solids in urine
• organic substances of urine:

  • urea
  • creatinine
  • uric acid
• chloride is the primary inorganic substances in the urine
• sodium is primarily from salt, and varies by intake
• potassium is combined with chloride and other salt
• sulfate is derived from amino acids
• ammonium regulates the blood and tissue fluid acidity
• calcium combines with chloride, sulfate, and phosphate
• dietary intake greatly influences the concentrations of these inorganic ocmpounds, making it difficult to establish normal levels
• urea and creatinine are the constituents that indicate that a fluid is urine
• cells, casts, crystals, mucus, bacteria are the formed elements of urine
• factors that influence urine concentrations:

  • physical activity
  • water intake
  • diet
  • disease
  • endocrine function
  • body metabolism/position
• urine volume is determined by the body's states of hydration
• water is the major body constituent of urine
• 1200-1500mL/day is the normal daily urine output, but 600-2000 is also considered normal.
• oliguria <400mL/day

  <1 mL/kg/hr in infants

  <0.5 mL/kg/hr in children
• anuria is the cessation of urine
• nocturia is increase urine at night
• urine excretion in nocturia: 2-3x during the day than the night
• polyuria greater than 2.5L/day
• polyuria = chronic glomerulonephritis

  oliguria = acute glomerulonephritis