What is the evaluation and management of hematuria?

Evaluation and Management of Hematuria

All patients with gross hematuria require urgent urologic referral due to >10% risk of malignancy, while microscopic hematuria requires a systematic evaluation with appropriate referrals based on risk factors and initial findings. 1

Initial Assessment and Risk Stratification

Confirmation of Hematuria

• Perform urinalysis with microscopic examination to confirm hematuria and assess for:
  • RBC morphology (dysmorphic RBCs suggest glomerular source)
  • Presence of casts (RBC casts suggest glomerulonephritis)
  • Pyuria (suggests infection)
  • Crystals (suggests stone disease)
  • Proteinuria (suggests glomerular disease) 1

Laboratory Evaluation

• Complete urinalysis
• Complete metabolic panel (including serum creatinine and BUN)
• Urine culture (to rule out infection)
• Urine cytology (to evaluate for malignant cells) 1

Risk Factors for Genitourinary Malignancy

• Age >40 years (higher risk if >60 years)
• Smoking history
• Male gender
• Occupational exposure to chemicals or dyes
• Previous urologic disorders
• Hypertension
• Diabetes 1

Management Algorithm

For Gross Hematuria (Visible Blood)

1. Immediate urologic referral is mandatory (risk of malignancy >10%) 1, 2
2. Immediate imaging for patients with trauma 1
3. Consider concurrent nephrology referral if:
   • eGFR <60 ml/min/1.73m²
   • Significant proteinuria
   • Dysmorphic RBCs or red cell casts 1

For Microscopic Hematuria

1. Rule out benign causes:

   • Urinary tract infection
   • Menstruation
   • Vigorous exercise
   • Trauma
   • Recent urologic procedures 1

2. If no benign cause identified:

   • Imaging of the urinary tract:

     • CT urography (preferred for most patients - 92% sensitivity, 93% specificity)
     • MR urography or ultrasound (for patients with renal insufficiency or contrast allergy)
     • Renal ultrasound (for younger patients, though only 50% sensitivity) 1

   • Referrals:

     • Urology referral if risk factors present or no benign cause identified
     • Nephrology referral if signs of glomerular disease present 1

Surveillance and Follow-up

For Negative Initial Evaluation

• Repeat urinalysis, urine cytology, and blood pressure at 6,12,24, and 36 months 1
• Immediate urologic reevaluation if:
  • Gross hematuria develops
  • Abnormal urinary cytology appears
  • Irritative voiding symptoms develop without infection 1

For Persistent Microscopic Hematuria

• Continue surveillance with repeat urinalysis within 12 months 1
• Consider additional evaluation if hematuria worsens 1

Common Pitfalls and Caveats

1. Inadequate referral rates: Research shows only 36% of primary care physicians refer patients with microscopic hematuria to urology, and only 69-77% refer those with gross hematuria 3. This represents a significant gap in recommended care that could delay diagnosis of serious conditions.

2. Age-based considerations: Patients ≤40 years have lower risk of malignancy but should still receive appropriate evaluation. In one study, only 1 malignancy was found in younger patients compared to 31 in older patients 4.

3. Interstitial cystitis and hematuria: Up to 41% of interstitial cystitis patients may have hematuria, but comprehensive evaluation rarely reveals malignancy 5. Nevertheless, standard evaluation is still warranted.

4. Imaging selection: CT urography offers superior sensitivity (92%) compared to ultrasound (50%) for detecting urinary tract pathology, though ultrasound may be appropriate for younger, lower-risk patients 1, 4.

5. Intensity of hematuria matters: Patients with <5 RBCs/HPF on three consecutive urinalyses are unlikely to have significant pathology and might be candidates for conservative follow-up 4.

The primary care provider's prompt referral and facilitation of the hematuria evaluation is critical for achieving the best possible outcome and avoiding complications of genitourinary disorders 6.