What is the appropriate diagnostic workup for a 79-year-old man on warfarin presenting with painless gross hematuria?

Workup for 79-Year-Old Man on Coumadin with Painless Hematuria

This patient requires urgent and complete urologic evaluation with cystoscopy and multiphasic CT urography, regardless of anticoagulation status. Anticoagulation does not cause hematuria—it only unmasks underlying pathology that demands investigation. 1

Immediate Diagnostic Steps

Confirm true hematuria before proceeding with extensive workup:

• Obtain microscopic urinalysis showing ≥3 red blood cells per high-power field (RBC/HPF) on a properly collected clean-catch midstream specimen 1
• Dipstick testing alone has only 65-99% specificity and can yield false positives from myoglobin, hemoglobin, or contaminants 1
• For gross (visible) hematuria, microscopic confirmation is still required to document the degree of bleeding 2

Obtain baseline laboratory studies:

• Serum creatinine, BUN, and complete metabolic panel to assess renal function 1, 2
• Complete blood count with platelets to evaluate for anemia and coagulopathy 2
• Urine culture (preferably before antibiotics) if infection is suspected 1, 3

Risk Stratification

This patient is automatically high-risk based on multiple factors:

• Age 79 years (males ≥60 years are high-risk) 1
• Painless gross hematuria carries a 30-40% risk of malignancy 1, 2
• Anticoagulation status does not reduce cancer risk—warfarin may unmask underlying urologic pathology 1, 4, 5

Additional high-risk features to document:

• Smoking history (>30 pack-years is high-risk for urothelial carcinoma) 1, 2
• Occupational exposure to chemicals/dyes (benzenes, aromatic amines) 1, 2
• Irritative voiding symptoms without infection 1
• History of pelvic irradiation or cyclophosphamide exposure 3

Mandatory Urologic Evaluation

Upper Tract Imaging

Multiphasic CT urography is the imaging procedure of choice:

• Includes unenhanced phase (detects calculi), nephrographic phase (evaluates renal parenchyma for masses), and excretory phase (assesses urothelium of upper tracts, ureters, and bladder) 1, 2, 3
• Demonstrates 96% sensitivity and 99% specificity for detecting renal cell carcinoma, transitional cell carcinoma, and urolithiasis 1, 2
• If CT is contraindicated due to severe renal insufficiency or contrast allergy, use MR urography or renal ultrasound with retrograde pyelography 1

Lower Tract Evaluation

Cystoscopy is mandatory for all patients with gross hematuria:

• Flexible cystoscopy is preferred over rigid cystoscopy—causes less pain with equivalent or superior diagnostic accuracy 1, 2
• Provides direct visualization of bladder mucosa, urethra, and ureteral orifices 1
• Bladder cancer accounts for 30-40% of gross hematuria cases and cannot be excluded by imaging alone 1, 2
• Should be performed urgently (within 24-48 hours) even if bleeding appears self-limited 2, 3

Adjunctive Testing

Voided urine cytology should be obtained:

• Particularly important in high-risk patients (age >60, smoking history, occupational exposures) 1, 2
• Helps detect high-grade urothelial carcinomas and carcinoma in situ 1
• Should not replace cystoscopy but serves as an adjunct 1, 2

Distinguishing Glomerular from Urologic Sources

Examine urinary sediment for glomerular indicators:

• >80% dysmorphic RBCs or presence of red cell casts indicates glomerular disease 1, 2
• Tea-colored or cola-colored urine suggests glomerular source 1, 2
• Significant proteinuria (protein-to-creatinine ratio >0.5 g/g) strongly suggests renal parenchymal disease 1

If glomerular features are present:

• Refer to nephrology in addition to completing the urologic evaluation 1, 2
• Glomerular disease does not eliminate the need for urologic assessment—malignancy can coexist with medical renal disease 1, 2

Management of Anticoagulation

Do not discontinue warfarin without consulting the prescribing clinician:

• The 2003 American Heart Association/American College of Cardiology guidelines state that bleeding at an INR of 3.0 is frequently associated with an underlying lesion in the gastrointestinal or urinary tract 1
• If bleeding is severe and life-threatening, consider vitamin K 10 mg by slow intravenous infusion supplemented with fresh plasma or prothrombin complex concentrate 1
• For non-life-threatening bleeding with INR in therapeutic range, warfarin can be resumed once bleeding stops and the underlying cause is corrected 1

The American Geriatrics Society recommends:

• More frequent INR monitoring may be required in older adults during illness or medication changes 1
• Evaluation of the cause of bleeding is required before adjusting warfarin dosage 1

Critical Pitfalls to Avoid

Never attribute hematuria solely to anticoagulation:

• Prospective studies show that 30% of anticoagulated patients with hematuria have significant genitourinary pathology including malignancy 5, 6
• Warfarin does not cause hematuria—it unmasks underlying disease 1, 4, 5
• Evaluation must proceed regardless of INR level or type of anticoagulation therapy 1

Never dismiss self-limited gross hematuria:

• Even single episodes carry 30-40% malignancy risk and require complete evaluation 1, 2
• Hematuria can precede bladder cancer diagnosis by many years 1

Never delay evaluation while "optimizing" anticoagulation:

• Diagnostic delays beyond 9 months are associated with worse cancer-specific survival 2
• Early identification of malignancy allows for aggressive surgical intervention 4

Follow-Up Protocol

If initial workup is negative but hematuria persists:

• Repeat urinalysis at 6,12,24, and 36 months with blood pressure monitoring at each visit 1, 2
• Consider repeat complete evaluation within 3-5 years for persistent hematuria in high-risk patients 1, 2
• After two consecutive negative annual urinalyses, further testing is unnecessary 1, 2

Immediate re-evaluation is warranted if:

• Recurrent gross hematuria develops 1, 2
• Significant increase in degree of microscopic hematuria occurs 1, 2
• New urologic symptoms appear 1, 2
• Development of hypertension, proteinuria, or evidence of glomerular bleeding 1, 2