What is the management approach for a patient with hematuria (blood in urine) without bacterial growth?

Management of Hematuria Without Bacterial Growth

For patients with hematuria without bacterial growth, a comprehensive risk-stratified evaluation is mandatory, including cystoscopy and upper tract imaging for high-risk patients, to rule out serious underlying conditions such as urinary tract malignancy. 1

Risk Stratification

Hematuria requires proper risk stratification to guide management:

Risk Categories (per AUA/SUFU guidelines):

• Low/Negligible risk (0-0.4%): 3-10 RBC/HPF + Age <60y (women) or <40y (men) + Never smoker or <10 pack-years
• Intermediate risk (0.2-3.1%): 11-25 RBC/HPF or Age 60+ (women)/40-59 (men) or 10-30 pack-years smoking
• High risk (1.3-6.3%): >25 RBC/HPF or Age 60+ (men) or >30 pack-years smoking 1

Initial Evaluation

1. Confirm hematuria: ≥3 red blood cells per high-power field (HPF) on properly collected specimens (2 of 3 specimens) 1

2. Laboratory assessment:

   • Serum creatinine and BUN
   • Complete blood count
   • Urinary sediment examination
   • 24-hour urine collection for protein quantification 1

3. Differentiate glomerular vs. non-glomerular source:

   • Glomerular indicators: dysmorphic RBCs, RBC casts, significant proteinuria (>500-1000mg/24hr)
   • Non-glomerular: normal-shaped RBCs, absence of casts 1

Imaging and Diagnostic Procedures

Imaging selection based on risk stratification:

1. Low-risk patients:

   • Renal ultrasound 1

2. Intermediate-risk patients:

   • Cystoscopy
   • Renal ultrasound 1

3. High-risk patients:

   • Cystoscopy (mandatory for all patients with gross hematuria)
   • Multi-phasic CT urography (preferred imaging)
   • MR urography if contrast allergy or renal insufficiency 1

Special Considerations

1. Anticoagulation status:

   • Does not change evaluation protocol
   • Patients on antiplatelet agents or anticoagulants require the same evaluation 1

2. Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS):

   • Consider if patient has bladder/pelvic pain and pressure/discomfort with urinary frequency
   • Symptoms should be present for at least six weeks with negative urine cultures
   • Cystoscopy should be performed if Hunner lesions are suspected 2

3. Cell wall deficient bacteria:

   • In rare cases, cell wall deficient bacteria may cause hematuria without showing growth on standard cultures
   • Consider specialized culture techniques if other evaluations are negative 3

Follow-up

• Repeat urinalysis at 6,12,24, and 36 months
• Immediate re-evaluation if recurrent gross hematuria, abnormal urinary cytology, or new irritative voiding symptoms occur 1
• If a non-malignant cause is identified, treat the underlying condition and confirm resolution with follow-up urinalysis 1

Common Pitfalls to Avoid

1. Attributing hematuria to anticoagulation without evaluating for underlying pathology 1

2. Neglecting to evaluate leukocyturia without bacteriuria, which may miss non-infectious causes 1

3. Using urinary cytology or urine-based molecular markers for initial bladder cancer detection is not recommended 1

4. Assuming "idiopathic" cause without thorough evaluation - approximately 80% of asymptomatic hematuria cases are idiopathic, but this is a diagnosis of exclusion 4

5. Missing glomerular causes - nephrology referral should be considered for possible renal biopsy if glomerular disease is suspected 1