What are the next steps for someone experiencing decreased eGFR (Estimated Glomerular Filtration Rate), hematuria, and dysuria?

Evaluation and Management of Decreased eGFR with Hematuria and Dysuria

Repeat testing immediately to confirm chronicity, then urgently investigate for urinary tract infection, glomerulonephritis, or other acute kidney pathology—this presentation demands prompt evaluation to distinguish between acute kidney injury and chronic kidney disease, as the combination of decreased eGFR with hematuria and dysuria suggests either active infection or glomerular disease requiring specific treatment. 1

Immediate Diagnostic Steps

Confirm the Findings

• Repeat eGFR and urinalysis within days to weeks to distinguish acute kidney injury (AKI) from chronic kidney disease (CKD), as a single abnormal measurement should never be assumed to represent chronicity 1
• Obtain urinary albumin-to-creatinine ratio (UACR) on a spot urine sample to quantify proteinuria 1
• Perform urine microscopy to characterize the hematuria—look specifically for red blood cell casts, dysmorphic RBCs, or white blood cells which indicate different pathologies 1

Rule Out Infection First

• Obtain urine culture immediately before any other workup, as dysuria with hematuria strongly suggests urinary tract infection (UTI), which is the most common and treatable cause 2
• If UTI is confirmed, treat appropriately and recheck urinalysis 2-4 weeks after treatment to determine if hematuria persists 3

Establishing Chronicity and Cause

If Initial Tests Suggest CKD (Not AKI)

Proof of chronicity requires evidence of kidney abnormalities present for ≥3 months, established through: 1

• Review of past eGFR measurements
• Review of past urinalysis results
• Imaging showing reduced kidney size or cortical thinning
• Medical history of conditions causing CKD (diabetes, hypertension)
• Repeat measurements at and beyond 3 months

Determine the Underlying Cause

Establish etiology using: 1

• Clinical context: Duration of symptoms, presence of diabetes or hypertension
• Medication review: NSAIDs, ACE inhibitors, ARBs can cause both decreased eGFR and hematuria 1
• Laboratory tests:
  • Complete blood count
  • Serum creatinine and cystatin C (use eGFRcr-cys for more accurate staging) 1
  • Blood glucose and HbA1c
  • Lipid panel
  • Serum potassium 1
• Imaging: Renal ultrasound to assess kidney size, cortical thickness, and structural abnormalities 1, 4

Red Flags Requiring Urgent Nephrology Referral

Refer immediately to nephrology if any of the following are present: 1

• Active urinary sediment with red or white blood cell casts (suggests glomerulonephritis)
• Rapidly increasing albuminuria or development of nephrotic-range proteinuria
• Rapidly decreasing eGFR (>5 mL/min/1.73 m²/year) 1
• Gross hematuria without infection
• eGFR <30 mL/min/1.73 m² 1
• Uncertainty about etiology of kidney disease 1
• Hematuria with proteinuria in the absence of infection (suggests glomerular disease) 5

Consider Kidney Biopsy

Kidney biopsy should be performed when: 1

• The cause remains unclear after initial workup
• Glomerulonephritis is suspected (hematuria with proteinuria, active sediment)
• Results would guide specific treatment decisions

Common Pitfalls to Avoid

Don't Assume Diabetic Kidney Disease

• While diabetic kidney disease typically presents with albuminuria and gradually progressive eGFR loss, the presence of dysuria and hematuria is atypical and suggests alternative or superimposed causes 1
• In type 1 diabetes, kidney disease without retinopathy is rare and should prompt investigation for other causes 1
• Active urinary sediment or rapidly changing kidney function mandates nephrology evaluation even in diabetic patients 1

Don't Overlook Medication Effects

• ACE inhibitors and ARBs can cause acute decreases in eGFR through hemodynamic effects, particularly with volume depletion 1
• NSAIDs are nephrotoxic and can cause both decreased eGFR and hematuria 1, 3
• Review and potentially hold nephrotoxic medications while investigating 1

Don't Dismiss Hematuria as Benign

• Persistent or recurrent hematuria over multiple measurements increases the likelihood of underlying glomerular disease, even without immediate eGFR decline 5
• Hematuria associated with anticoagulation still requires full evaluation, as it frequently reveals significant urologic pathology 3

Initial Management While Awaiting Workup

Blood Pressure Control

• Target blood pressure <130/80 mmHg if CKD is confirmed 1
• Use ACE inhibitor or ARB if hypertension is present with UACR ≥30 mg/g, but monitor creatinine and potassium closely 1

Monitor for Complications

• Check serum potassium within 1-2 weeks if starting or continuing ACE inhibitor/ARB 1
• Assess for volume depletion which can worsen kidney function 1
• Screen for and treat urinary tract infections promptly, as patients with decreased eGFR have increased infection risk 2

Avoid Further Kidney Injury

• Minimize exposure to nephrotoxins including NSAIDs and iodinated contrast 1
• Ensure appropriate medication dosing for the level of kidney function 1