Management of Urinalysis Showing Large Blood and Leukocytes
The next step depends entirely on whether the patient has symptoms: if asymptomatic, no urine culture or antibiotics are needed; if symptomatic with dysuria, frequency, urgency, or fever, obtain a urine culture before starting antibiotics. 1
Asymptomatic Patients
For patients without urinary symptoms, the presence of blood and leukocytes on urinalysis does not warrant immediate intervention. 1
- No urine culture should be obtained in asymptomatic individuals, as the absence of pyuria has excellent negative predictive value for ruling out UTI 1
- Leukocyte esterase alone has moderate sensitivity (83%) but limited specificity (78%) for UTI, making it a poor standalone diagnostic marker 1
- When both leukocyte esterase and nitrite are negative, the negative predictive value is excellent for excluding UTI 1
- Asymptomatic bacteriuria with pyuria is common (15-50% in older adults) and does not require treatment 1
Critical Pitfall to Avoid
Treating leukocytes in asymptomatic patients leads to unnecessary antibiotic use and contributes to antimicrobial resistance. 1 The Infectious Diseases Society of America explicitly states that urinalysis and urine cultures should not be performed for asymptomatic individuals 1
Symptomatic Patients
If the patient has acute onset of dysuria, frequency, urgency, costovertebral angle tenderness, fever, rigors, or delirium, obtain a properly collected urine culture before starting antibiotics. 2
- A clean-catch midstream specimen is appropriate for adults 1
- Consider catheterization if contamination is suspected 1
- Prescribe antibiotics unless urinalysis shows negative nitrite AND negative leukocyte esterase 2
Addressing the Hematuria Component
The blood on urinalysis requires microscopic confirmation with ≥3 red blood cells per high-power field before initiating further evaluation. 2, 3
Rule Out Benign Causes First
- If menstruation, viral illness, vigorous exercise, recent sexual activity, or trauma is suspected, repeat urinalysis 48 hours after cessation of the potential cause 3
- If infection is suspected based on symptoms, obtain urine culture; if positive, treat appropriately and repeat urinalysis 6 weeks after treatment to confirm resolution 2, 3
When to Pursue Urologic Evaluation
All patients with gross (visible) hematuria should be referred for urologic evaluation due to high risk of underlying urinary tract malignancy. 3 Specifically inquire about visible blood in urine during routine review of systems, as it is often underreported but significantly increases cancer risk (odds ratio 7.2) 3
For microscopic hematuria that persists after excluding benign causes and treating infection:
- High-risk patients (age ≥60 years, >30 pack-years smoking, >25 RBC/HPF, history of gross hematuria, occupational chemical exposure) require cystoscopy and upper tract imaging 3
- Intermediate-risk patients (women age 50-59 or men age 40-59,10-30 pack-years smoking, 11-25 RBC/HPF) may undergo cystoscopy with imaging through shared decision-making 3
- Low-risk patients may undergo repeat urinalysis in 6 months or proceed with evaluation based on patient preference 3
Evaluate for Glomerular Source
Examine urinary sediment for dysmorphic red blood cells (>80%), red cell casts, and assess for proteinuria (>500 mg/24 hours) and elevated serum creatinine. 3 These findings indicate glomerular disease and warrant nephrology referral 3
Special Population Considerations
Older Adults and Frail Patients
In older adults, evaluation is indicated only with acute onset of specific urinary symptoms 2, 1. The prevalence of asymptomatic bacteriuria is 15-50% in non-catheterized residents of long-term care facilities and does not require treatment 1
Febrile Infants and Children (2 months to 2 years)
If UTI is clinically suspected, obtain a urine culture with catheterization preferred over bag specimens due to high contamination rates 2, 1