What is the management approach for patients with impaired renal function, specifically those with a glomerular filtration rate (GFR) less than 15?

Management of Patients with GFR Less Than 15 mL/min/1.73 m²

Conservative management should continue until GFR falls below 15 mL/min/1.73 m², at which point preparation for renal replacement therapy becomes urgent, but dialysis initiation must be driven by clinical symptoms—not by GFR alone—as early dialysis provides no survival benefit and may cause harm. 1, 2

Immediate Nephrology Referral

• Refer immediately to nephrology if not already established, as consultation at eGFR <30 reduces costs, improves quality of care, and delays dialysis. 3
• At GFR 15, the patient is approaching Stage 5 CKD (GFR <15), making preparation for renal replacement therapy urgent. 3

Verify True Renal Function Before Major Decisions

• Obtain measured GFR using 24-hour urine collection for creatinine and urea clearances rather than relying solely on estimated GFR, particularly in patients with unusual creatinine generation (malnutrition, amputation, extreme muscle mass) or altered tubular secretion (liver disease, certain medications). 1, 4
• Creatinine-based estimates may be inaccurate in these populations, leading to premature or delayed interventions. 1

Monitoring Frequency

• Check creatinine, eGFR, and potassium at least monthly, increasing to weekly or more frequently if rapid progression or clinical instability occurs. 2
• Monitor blood pressure at every clinic visit (minimum every 3 months). 2
• Monitor nutritional status (body weight and serum albumin) every 3 months. 2

Clinical Indications for Dialysis Initiation (NOT GFR-Based)

Dialysis should be initiated based on clinical symptoms, NOT GFR alone. 1, 2, 4

Absolute Indications:

• Uremic symptoms: pericarditis, encephalopathy, intractable nausea/vomiting, bleeding diathesis 2, 4
• Volume overload refractory to diuretic therapy 2, 4
• Uncontrolled hypertension despite maximal medical management 2, 4
• Severe metabolic derangements: hyperkalemia unresponsive to medical therapy, severe metabolic acidosis 2, 4
• Protein-energy malnutrition that develops or persists despite vigorous nutritional intervention with no apparent cause other than low nutrient intake 1, 4

Evidence Against Early Dialysis:

• When corrections are made for lead-time bias, there is no clear survival advantage to starting dialysis earlier at higher GFRs versus lower GFRs. 1
• Patients with comorbidities tend to initiate dialysis at higher GFRs, but this reflects their frailty—not a benefit from early initiation. 1
• Dialysis is not innocuous: it imposes significant burden on patients and families, and hemodialysis-related hypotension may accelerate loss of residual kidney function. 1, 4

Conservative Management Until Dialysis Indicated

Blood Pressure Management:

• Target systolic BP <130 mmHg and diastolic BP <80 mmHg. 3, 2
• Use ACE inhibitor or ARB as first-line agent for blood pressure control and kidney protection. 3, 2
• Do NOT routinely discontinue ACE-I/ARB at GFR <30, as they remain nephroprotective. 2
• Monitor GFR and potassium within 1 week of starting or dose escalation. 2

Critical Medication Adjustments:

• Metformin: CONTRAINDICATED at eGFR <30—discontinue immediately. 3
• Insulin: Reduce total daily dose by 35-50% due to decreased renal clearance and reduced gluconeogenesis. 3
• Canagliflozin: Maximum 100 mg daily; may continue for kidney and cardiovascular benefit until dialysis. 3
• Avoid NSAIDs entirely. 2
• Reduce doses of opioids and beta-blockers. 2

Screening for CKD Complications:

• Screen for and manage secondary hyperparathyroidism as part of CKD-mineral bone disease management. 3
• Evaluate and correct metabolic acidosis, which commonly develops at this level of kidney function. 3

Fluid Management:

• Consult nephrology before administering IV fluids, as patients at GFR 15 are at significantly increased risk of fluid overload. 3
• Monitor daily for signs of fluid overload when IV fluids are necessary. 3

Preparation for Renal Replacement Therapy

Patient Education:

• Provide structured education regarding the progressive nature of kidney disease and potential need for dialysis or transplantation. 3, 2
• Discuss modality options: hemodialysis (in-center vs. home), peritoneal dialysis, and kidney transplantation. 2
• Encourage maintenance of employment and normal activities as long as possible. 2

Vascular Access Planning (if hemodialysis anticipated):

• Preserve veins suitable for vascular access—avoid venipuncture and IV catheters in non-dominant arm. 2
• Refer for surgery to attempt construction of primary AV fistula if hemodialysis is planned, ideally when GFR approaches 15-20. 2

Consider Preemptive Options:

• It may be optimal to perform kidney transplantation or begin home dialysis before patients reach CKD stage 5 (GFR <15). 1, 3

If Dialysis Is Indicated: Initiation Protocol

"Low and Slow" Approach:

• The first dialysis treatment should use a "low and slow" approach to minimize dialysis disequilibrium syndrome and hemodynamic instability. 4
• Initial session duration: 2-2.5 hours with reduced blood flow rates of 200-250 mL/min. 4
• Minimal ultrafiltration during the first session. 4
• Frequent vital sign monitoring every 15-30 minutes during the first session, with close observation for neurological symptoms. 4
• Gradual dose escalation over subsequent sessions as tolerated. 4

Critical Pitfalls to Avoid

• DO NOT initiate dialysis based on GFR alone—early dialysis in asymptomatic patients provides no survival benefit and may cause harm. 1, 2, 4
• DO NOT use aggressive first dialysis sessions—rapid removal of uremic toxins can cause cerebral edema, seizures, and cardiovascular instability. 4
• DO NOT cause hemodialysis-related hypotension, which may accelerate loss of residual kidney function. 1, 4
• DO NOT routinely discontinue ACE-I/ARB at this GFR level, as they remain nephroprotective. 2

Nuances in Special Populations

• Patients with diabetes generally initiate dialysis at higher levels of residual kidney function than non-diabetic patients, though this is a consensus practice rather than evidence-based. 1
• Elderly patients may have higher average GFR at initiation (10-10.5 mL/min/1.73 m²) compared to young and middle-aged adults (7-9 mL/min/1.73 m²). 1
• Children and adolescents: Higher eGFR at dialysis initiation is associated with higher mortality risk, suggesting benefit from conservative management until lower GFR thresholds. 5