What is the initial evaluation and treatment approach for a patient presenting to the ER with urinary sediment?

Management of Urinary Sediment from the Emergency Department

Initial Confirmation and Characterization

Microscopic examination of urinary sediment is essential and must be performed on a freshly voided, clean-catch, midstream specimen to confirm true hematuria (≥3 RBCs/HPF) before initiating any workup. 1

• Dipstick positivity alone has limited specificity (65-99%) and requires microscopic confirmation 1
• Examine the sediment for dysmorphic RBCs, red cell casts, white cell casts, crystals, and other formed elements 1, 2
• Document the percentage of dysmorphic RBCs: >80% suggests glomerular origin, while >80% normal RBCs suggests lower urinary tract bleeding 1
• Look specifically for red cell casts, which are pathognomonic for glomerular disease 1

Distinguish Glomerular from Non-Glomerular Sources

Features Suggesting Glomerular Disease (Nephrology Referral Indicated)

• Tea-colored or cola-colored urine (not bright red) 1, 3
• Significant proteinuria: >500-1000 mg/24 hours or protein-to-creatinine ratio >0.5 g/g 1, 3
• Dysmorphic RBCs >50-80% or acanthocytes >5% 1
• Red cell casts present 1
• Elevated serum creatinine or declining renal function 1, 3
• Hypertension accompanying hematuria 1, 3

Features Suggesting Urologic Source (Urology Referral Indicated)

• Bright red blood in urine 3
• Monomorphic (normal-appearing) RBCs >80% 1
• Absence of casts and minimal or no proteinuria 1, 3
• Flank pain, suprapubic pain, or dysuria 3
• Irritative voiding symptoms (urgency, frequency, nocturia) 3

Risk Stratification for Malignancy

All patients with gross hematuria require urgent urologic evaluation regardless of whether bleeding is self-limited, as gross hematuria carries a 30-40% risk of malignancy. 1, 3

High-Risk Features Requiring Complete Urologic Evaluation

• Age ≥60 years (males) or ≥60 years (females) 1, 3, 4
• Smoking history >30 pack-years 1, 3
• History of gross hematuria (even if currently microscopic) 1, 3
• Occupational exposure to benzenes, aromatic amines, or other chemicals/dyes 1, 3
• Irritative voiding symptoms without infection 1, 3
• >25 RBCs/HPF on microscopy 3

Intermediate-Risk Features (Shared Decision-Making)

• Age 40-59 years (males) or similar age range (females) 1, 3
• Smoking history 10-30 pack-years 3
• 10-25 RBCs/HPF on microscopy 3

Exclude Transient Benign Causes

Before proceeding with extensive workup, exclude:

• Recent vigorous exercise (can cause transient hematuria) 1, 3
• Menstruation (contamination in women) 1, 3
• Recent sexual activity 3
• Viral illness 3
• Trauma 3
• Active urinary tract infection: Obtain urine culture if infection suspected, preferably before antibiotics 1, 3

Critical caveat: Anticoagulation or antiplatelet therapy does NOT cause hematuria and should never defer evaluation—these medications may only unmask underlying pathology. 1, 3

Complete Urologic Evaluation (for Non-Glomerular Hematuria)

Upper Tract Imaging

Multiphasic CT urography is the preferred imaging modality for detecting renal cell carcinoma, transitional cell carcinoma, and urolithiasis 1, 3, 4

• Includes unenhanced, nephrographic phase, and excretory phase images 3
• If CT contraindicated: MR urography or renal ultrasound with retrograde pyelography 3
• Renal ultrasound alone is insufficient for comprehensive upper tract evaluation 1, 3

Lower Tract Evaluation

Cystoscopy is mandatory for all patients with gross hematuria and for microscopic hematuria patients with risk factors 1, 3

• Flexible cystoscopy is preferred over rigid cystoscopy (less pain, equivalent or superior diagnostic accuracy) 3
• Visualizes bladder mucosa, urethra, and ureteral orifices 3

Laboratory Testing

• Serum creatinine, BUN, complete metabolic panel to assess renal function 3
• Complete blood count with platelets to evaluate for coagulopathy 3
• Voided urine cytology in high-risk patients (age >60, smoking history, irritative symptoms) 3
• Urine culture if infection suspected 3

Nephrology Evaluation (for Glomerular Hematuria)

When glomerular features are present:

• Quantify proteinuria: 24-hour urine collection or spot protein-to-creatinine ratio 1, 3
• Complement levels (C3, C4) to evaluate for post-infectious GN or lupus nephritis 3
• ANA and ANCA testing if vasculitis suspected 3
• Renal ultrasound to evaluate kidney size, echogenicity, and structural abnormalities 3
• Consider renal biopsy for definitive diagnosis if significant proteinuria (>1000 mg/24h), red cell casts, or progressive renal dysfunction 1, 3

Important: The presence of glomerular features does NOT eliminate the need for urologic evaluation—malignancy can coexist with medical renal disease, so both evaluations should be completed. 3

Follow-Up Protocol for Negative Initial Evaluation

If complete workup is negative but hematuria persists:

• Repeat urinalysis at 6,12,24, and 36 months with blood pressure monitoring at each visit 1, 3
• After two consecutive negative annual urinalyses, no further testing for asymptomatic microhematuria is necessary 3

Immediate Re-Evaluation Warranted If:

• Gross hematuria develops 1, 3
• Significant increase in degree of microscopic hematuria 1, 3
• New urologic symptoms appear (flank pain, dysuria, irritative voiding) 1, 3
• Development of hypertension, proteinuria, or evidence of glomerular bleeding 1, 3

Common Pitfalls to Avoid

• Never ignore gross hematuria, even if self-limited—30-40% malignancy risk mandates urgent urologic referral 1, 3
• Do not attribute hematuria to anticoagulation/antiplatelet therapy without full investigation 1, 3
• Do not rely solely on dipstick testing—confirm with microscopic urinalysis showing ≥3 RBCs/HPF 1
• Do not prescribe empiric antibiotics for hematuria without documented infection—this delays cancer diagnosis 3
• Do not defer evaluation in women—women have higher case-fatality rates for bladder cancer despite lower evaluation rates 3
• Examination of urinary sediment is an essential skill that should not be delegated solely to central laboratories 1, 2