What is the recommended management for hematuria in an outpatient setting?

Management of Hematuria in the Outpatient Setting

The recommended management for hematuria in an outpatient setting involves confirming true hematuria with microscopic examination, determining whether the source is glomerular or non-glomerular, and following a risk-stratified approach to further evaluation and referral. 1

Initial Evaluation

• Confirm the presence of true hematuria with microscopic examination (≥3 red blood cells per high-power field) rather than relying solely on dipstick results 1
• Rule out benign causes of hematuria, including:
  • Viral illness 1
  • Menstruation 2
  • Vigorous exercise 2
  • Sexual activity 3
  • Trauma 3
• For suspected urinary tract infection, obtain urine culture; if positive, treat appropriately and repeat urinalysis 6 weeks after treatment to confirm resolution 1
• If a benign cause is suspected, repeat urinalysis 48 hours after cessation of the potential cause 1, 2
• In women, obtain a catheterized specimen if a clean-catch specimen cannot be reliably obtained due to vaginal contamination 2, 3

Source Determination (Glomerular vs. Non-Glomerular)

• Examine urinary sediment for dysmorphic red blood cells and red cell casts (suggesting glomerular origin) 1, 3
• Assess for proteinuria and measure serum creatinine 1, 3
• Indicators of glomerular source include:
  • Significant proteinuria (>500 mg/24 hours) 1, 3
  • Dysmorphic RBCs (>80%) 1, 3
  • Red cell casts 1, 3
  • Elevated serum creatinine 1, 3
• Indicators of non-glomerular (urologic) source include:
  • Normal-shaped RBCs (>80%) 3
  • Minimal proteinuria (<500 mg/24 hours) 3
  • Normal serum creatinine 3

Risk Stratification

• Risk factors for significant urologic disease include:
  • Age >40 years 1, 3
  • Smoking history 1, 3
  • Occupational exposure to chemicals or dyes (benzenes or aromatic amines) 1, 3
  • Irritative voiding symptoms 1, 3
  • History of urinary tract infection 1, 3
  • Analgesic abuse 1
  • History of pelvic irradiation 1
  • Previous urologic disorder 3
  • History of gross hematuria 3, 4

Management Algorithm

For Glomerular Source:

• Refer to nephrology if:
  • Proteinuria >1,000 mg/24 hours 3
  • Proteinuria >500 mg/24 hours that is persistent or increasing 3
  • Red cell casts 3
  • Predominantly dysmorphic RBCs 3
  • Hematuria persists with development of hypertension 1

For Non-Glomerular (Urologic) Source:

• Complete urologic evaluation, including:
  • History and physical examination 3, 4
  • Radiologic imaging of upper urinary tract (CT urography recommended) 3, 5
  • Cystoscopic examination of urinary bladder 3, 5
• Refer to urology if:
  • Age >40 years 3
  • Smoking history 3
  • History of gross hematuria (risk of malignancy >10%) 3, 4
  • Occupational exposure to chemicals or dyes 3
  • Previous urologic disorder 3
  • Irritative voiding symptoms 3
  • Recurrent urinary tract infections 3

Follow-up Recommendations

• For patients with persistent hematuria after negative initial evaluation:
  • Repeat urinalysis at 6,12,24, and 36 months 1, 3
  • Monitor blood pressure 1, 3
  • Consider nephrology referral if hematuria persists with development of hypertension, proteinuria, or evidence of glomerular bleeding 1, 3
• For patients with isolated hematuria (no proteinuria or other abnormalities):
  • Follow for development of hypertension, renal insufficiency, or proteinuria 3

Important Caveats and Pitfalls

• Do not assume that menstruation is the cause of hematuria without proper verification through repeat testing after menstruation 2
• Do not neglect evaluation of persistent hematuria even if there is a potential benign cause 2
• Be aware that contamination from vaginal bleeding during menstruation can produce false-positive results for hematuria 2
• Patients with microscopic hematuria, negative urologic evaluation, and no evidence of glomerular bleeding have low risk for progressive renal disease but should still be monitored 3
• Microscopic hematuria has a lower risk of malignancy (2.6% to 4%) compared to gross hematuria (30% to 40%), but still requires thorough evaluation 2, 4
• Acute urinary retention is a common acute presentation of macroscopic hematuria and may require continuous irrigation 6