What is the initial workup for a patient presenting with hematuria?

Initial Workup for Hematuria

The initial workup for a patient presenting with hematuria should include a thorough history, physical examination, urinalysis with microscopic confirmation, and risk stratification to guide subsequent imaging and specialist referral. 1

Classification and Definition

Hematuria is classified into two main categories:

• Gross hematuria: Visible blood in urine (30-40% risk of malignancy)
• Microscopic hematuria: Defined as ≥3 red blood cells per high-power field on microscopic evaluation of urinary sediment from two of three properly collected specimens 1

Initial Evaluation Algorithm

Step 1: History and Risk Factor Assessment

Look specifically for:

• Risk factors for urologic malignancy:

  • Age >35 years
  • Male gender
  • Smoking history
  • Occupational exposure to chemicals or dyes (benzenes, aromatic amines)
  • History of gross hematuria
  • Previous urologic disorder or disease
  • Irritative voiding symptoms
  • History of pelvic irradiation
  • Chronic urinary tract infection
  • Exposure to carcinogens or chemotherapy
  • Chronic indwelling foreign body 1

• Potential benign causes:

  • Vigorous exercise
  • Menstruation
  • Sexual activity
  • Trauma
  • Recent urologic procedures
  • Infection 1

Step 2: Urinalysis and Laboratory Testing

• Confirm hematuria with microscopic examination (dipstick alone has limited specificity of 65-99%) 1
• Urine culture to rule out infection
• Assess for glomerular source by checking for:
  • Significant proteinuria (>1g/24hr)
  • Red cell casts
  • Dysmorphic red blood cells (requires phase contrast microscopy)
  • Elevated serum creatinine 1

Step 3: Risk-Based Pathway Selection

Pathway A: If signs of renal parenchymal disease are present:

• Significant proteinuria
• Dysmorphic RBCs or RBC casts
• Elevated serum creatinine
• → Nephrology referral 1

Pathway B: If no signs of renal disease but urologic evaluation indicated:

• Gross hematuria (all cases)
• Microscopic hematuria with risk factors
• → Complete urologic workup 1

Urologic Evaluation Components

1. Imaging of the upper urinary tract:

   • CT urography (CTU) is the preferred modality for adults with hematuria 1
   • Includes unenhanced images followed by contrast-enhanced nephrographic and excretory phases
   • Superior for detecting urinary stones, renal masses, and urothelial lesions 1

2. Cystoscopy:

   • Recommended for all patients with gross hematuria
   • Recommended for patients >40 years with microscopic hematuria
   • May be deferred in low-risk patients <40 years without risk factors 1

3. Urine cytology:

   • Particularly useful for detecting high-grade tumors and carcinoma in situ 1

Special Considerations

• Gross hematuria: Requires urgent and complete evaluation due to high malignancy risk (30-40%) 1
• Anticoagulant therapy: Does not alter the need for urologic evaluation 1
• Persistent hematuria: Warrants continued surveillance even after initial negative evaluation 1
• Age consideration: Patients ≤40 years with microscopic hematuria and no risk factors may undergo less extensive initial evaluation 2

Follow-up Recommendations

For patients with negative initial evaluation:

• Repeat urinalysis, urine cytology, and blood pressure at 6,12,24, and 36 months
• Immediate re-evaluation if gross hematuria, abnormal cytology, or irritative voiding symptoms develop 1

Common Pitfalls to Avoid

1. Relying solely on dipstick testing without microscopic confirmation
2. Failing to evaluate for renal parenchymal disease when proteinuria or dysmorphic RBCs are present
3. Assuming UTI as the cause without confirming with culture and follow-up urinalysis after treatment
4. Neglecting follow-up in patients with persistent hematuria despite negative initial evaluation
5. Underestimating the significance of gross hematuria, which requires urgent and complete evaluation regardless of age or risk factors

Remember that gross hematuria carries a significantly higher risk of malignancy and demands prompt, thorough evaluation in all cases.