What are the indications for dialysis in patients with impaired renal function, particularly older adults with a history of diabetes, hypertension, or other kidney diseases?

Indications for Dialysis in Patients with Impaired Renal Function

Dialysis should be initiated based on clinical symptoms and life-threatening complications of kidney failure—not solely on GFR thresholds—with absolute indications including uremic complications (pericarditis, encephalopathy, seizures, neuropathy), refractory hyperkalemia >6.0 mmol/L, severe metabolic acidosis unresponsive to medical therapy, and volume overload refractory to diuretics. 1, 2

Absolute (Emergent) Indications

These require immediate dialysis initiation regardless of GFR:

• Uremic complications: Pericarditis, encephalopathy, seizures, or uremic neuropathy mandate urgent dialytic intervention 1, 2
• Life-threatening hyperkalemia: Potassium >6.0 mmol/L or persistent hyperkalemia unresponsive to medical therapy, particularly with ECG changes 2
• Refractory volume overload: Fluid overload unresponsive to aggressive diuretic therapy 1, 2
• Severe metabolic acidosis: Acidosis that cannot be controlled with medical management 1, 2
• Serositis: Including uremic pericarditis or pleuritis 1

Relative (Urgent) Indications

These typically warrant dialysis initiation within days:

• Progressive deterioration in nutritional status despite dietary intervention 1
• Refractory pruritus unresponsive to medical management 1
• Cognitive impairment attributable to uremia 1
• Inability to control blood pressure despite optimal medical therapy 1
• Progressive hyperphosphatemia (>6 mg/dL) with risk of calcium-phosphate precipitation 1, 2

GFR Thresholds: Context Matters

Do not initiate dialysis based on GFR alone—symptom burden should drive the decision:

• GFR 5-10 mL/min/1.73 m²: This range typically correlates with uremic symptom development, but timing must be individualized based on clinical presentation 1, 3
• GFR <15 mL/min/1.73 m²: Defined as kidney failure, with 98% of US patients beginning dialysis below this threshold 1
• Early initiation (GFR >10 mL/min/1.73 m²): Not associated with morbidity or mortality benefit and should be avoided in asymptomatic patients 3
• Asymptomatic patients: Dialysis may be safely delayed until GFR reaches 5-7 mL/min/1.73 m² with careful monitoring and patient education 3

Critical Caveat on GFR

Creatinine-based eGFR formulas are inaccurate in ESRD patients, so never base the dialysis decision solely on calculated GFR 3

Special Considerations for Older Adults with Diabetes and Hypertension

For older adults with multiple comorbidities, dialysis initiation requires careful risk-benefit assessment:

• Higher competing mortality risks: Older adults with diabetes and hypertension face significant non-renal mortality that may outweigh dialysis benefits 1
• Quality of life considerations: Dialysis may worsen outcomes and quality of life in frail elderly patients with multiple comorbidities 3
• Conservative management alternative: Comprehensive palliative care is a reasonable option for those with limited life expectancy or who wish to avoid medical interventions 1, 4
• Shared decision-making: The decision must involve physician, patient, and family members, tailored to individual needs and goals 3

Pre-Dialysis Preparation (When Dialysis is Anticipated)

Begin preparation when GFR <20 mL/min/1.73 m² with progressive, irreversible CKD:

• Multidisciplinary management: Access to dietary counseling, education about renal replacement therapy modalities, and psychological/social support 1
• Vascular access planning: Preserve peripheral veins in stage III-V CKD patients to facilitate future hemodialysis access 1, 4
• Transplant evaluation: Consider preemptive living donor kidney transplantation for appropriate candidates with GFR <20 mL/min/1.73 m² 1
• Timely nephrology referral: Essential to optimize disease management and allow adequate pre-dialysis planning 4, 3

Dialysis Modality Selection

Intermittent hemodialysis (IHD) should be the initial modality for most patients requiring rapid solute and electrolyte removal 2:

• IHD advantages: Superior efficiency for removing urea, potassium, phosphate, and uric acid compared to peritoneal dialysis 2
• Continuous renal replacement therapy (CRRT): Reserved for hemodynamically unstable patients, though it provides better azotemia control and allows improved nutritional support 2
• Frequent (daily) dialysis: Recommended when there is continuous metabolite release, such as in tumor lysis syndrome 2

Common Pitfalls to Avoid

• Do not treat asymptomatic hypocalcemia: Calcium supplementation in the setting of hyperphosphatemia worsens calcium-phosphate precipitation in tissues; only symptomatic hypocalcemia (tetany, seizures) requires cautious calcium gluconate 2
• Do not delay dialysis for "borderline" hyperkalemia with symptoms: Even moderate hyperkalemia (5.3-6.0 mmol/L) requires dialysis when accompanied by uremic symptoms or ECG changes 2
• Do not initiate early dialysis in asymptomatic patients: Early initiation (eGFR >10 mL/min/1.73 m²) provides no survival benefit and may cause harm 3, 5
• Do not ignore baseline renal function and prior AKI history: These are strong predictors of dialysis dependence and long-term outcomes 6, 7