How to manage a patient with a normal Urinalysis (UA) but with 1+ hematuria?

Management of Normal Urinalysis with 1+ Blood

Patients with isolated 1+ hematuria on urinalysis and no other abnormal findings should be referred for urologic evaluation, particularly if they are over 40 years old or have risk factors for urologic malignancy.

Understanding Microscopic Hematuria

Microscopic hematuria is defined as ≥3 red blood cells per high-power field on microscopic evaluation of at least two properly collected urine specimens. The finding of 1+ blood on dipstick urinalysis indicates microscopic hematuria that requires further evaluation to rule out significant underlying pathology.

Initial Assessment

When evaluating a patient with 1+ blood on urinalysis:

1. Exclude benign causes:

   • Menstruation
   • Vigorous exercise
   • Sexual activity
   • Viral illness
   • Recent trauma
   • Urinary tract infection

2. Assess for signs of primary renal disease:

   • Presence of significant proteinuria
   • Dysmorphic red blood cells or red cell casts
   • Elevated serum creatinine level

Management Algorithm

Step 1: Determine if renal or urologic evaluation is needed

If any of these are present, pursue renal evaluation:

• Significant proteinuria (>500 mg/24 hours)
• Dysmorphic red blood cells or red cell casts
• Elevated serum creatinine

If none of the above are present, proceed with urologic evaluation, especially if any risk factors exist:

• Age >40 years
• Smoking history
• Occupational exposure to chemicals or dyes
• History of gross hematuria
• Previous urologic disorder
• Irritative voiding symptoms
• Recurrent UTIs despite appropriate antibiotics

Step 2: Urologic Evaluation

According to the AUA guidelines, the urologic evaluation should include 1, 2:

1. Imaging:

   • CT urography is the preferred imaging modality (sensitivity 92%, specificity 93%)
   • MR urography for patients with contrast allergy or renal insufficiency
   • Renal ultrasound as an alternative, particularly in younger patients

2. Cystoscopy:

   • Recommended for all patients over 40 years with microscopic hematuria
   • Flexible cystoscopy is preferred due to equivalent diagnostic accuracy with less discomfort

Special Considerations

Patients with Hunner Lesions

For patients with symptoms suggesting interstitial cystitis/bladder pain syndrome and microscopic hematuria, cystoscopy should be performed to evaluate for Hunner lesions 1.

Anticoagulation

• Anticoagulation may exacerbate bleeding but rarely causes it without underlying pathology
• Anticoagulant therapy does not eliminate the need for complete hematuria evaluation 2

Follow-up Recommendations

For patients with negative initial evaluation:

• Repeat urinalysis at 6,12,24, and 36 months
• Monitor blood pressure
• Immediate re-evaluation if recurrent gross hematuria, abnormal urinary cytology, or new irritative voiding symptoms occur 2

For patients with persistent asymptomatic microhematuria:

• Annual urinalysis
• Consider repeat evaluation within 3-5 years for persistent or recurrent hematuria 2

Common Pitfalls to Avoid

1. Dismissing isolated microscopic hematuria - Even without other symptoms, 1+ blood requires evaluation, as it may be the only sign of serious underlying pathology including malignancy.

2. Incomplete evaluation - Failing to perform both imaging and cystoscopy can miss significant pathology.

3. Assuming anticoagulation is the cause - Anticoagulation rarely causes hematuria without underlying pathology.

4. Inadequate follow-up - Patients with negative initial evaluations still require monitoring as pathology may develop or become detectable later.

5. Missing glomerular causes - Failing to check for dysmorphic RBCs, casts, or proteinuria may lead to missed diagnosis of renal parenchymal disease.

By following this systematic approach to evaluating 1+ blood on urinalysis, clinicians can ensure appropriate detection and management of potentially serious underlying conditions while avoiding unnecessary testing in low-risk patients.