Lab

Urine Nitrite

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Urine Nitrite

  • Mechanism
  1. Some Bacteria reduce nitrates to nitrites
  2. Nitrite production typically requires urine standing (in Bladder) for at least 4 hours
    1. Infants do not hold their urine, and do not typically demonstrate nitrite on the urine sample
  • Efficacy
  • Interpretation
  1. Normal: Negative
  2. Positive
    1. Urinary Tract Infection
    2. Gross Hematuria
  1. Vaginal contaminant
  2. Phenazopyridine
  3. Dipstick exposed to air
    1. Close test strip containers immediately
    2. Strip exposed to air for 1 week: 33% false positive
    3. Strip exposed to air for 2 weeks: 75% false positive
  1. Increased Urine Specific Gravity
  2. Increased Urobilinogen
  3. Bacteria lacking nitrate reductase enzyme
  4. Urine pH <6.0
  5. Vitamin C supplementation
  6. Low nitrate diet