When should a patient be considered for hemodialysis due to impaired renal function?

When to Initiate Hemodialysis

Dialysis should be initiated based on clinical symptoms and complications—not GFR alone—typically when GFR falls between 5-10 mL/min/1.73 m² and one or more specific indications are present. 1

Primary Decision Framework: Symptoms Over Numbers

The most critical principle is that dialysis initiation must be driven by clinical indications rather than estimated GFR thresholds alone. 1, 2 Early initiation at higher GFR levels (>10 mL/min/1.73 m²) in asymptomatic patients provides no survival benefit and may cause harm. 2

Target GFR Range

• Conservative management should continue until GFR <15 mL/min/1.73 m² unless specific clinical indications mandate earlier initiation. 1, 2
• The optimal initiation window is typically GFR 5-10 mL/min/1.73 m² when clinical symptoms develop. 1
• Approximately 98% of U.S. patients begin dialysis when GFR <15 mL/min/1.73 m². 1

Absolute Clinical Indications for Dialysis (Override GFR)

Initiate hemodialysis when any one or more of the following are present, regardless of GFR level:

Uremic Symptoms

• Pericarditis (uremic pericardial friction rub or effusion) 1, 3
• Encephalopathy (altered mental status, asterixis, seizures) 1, 3
• Intractable nausea/vomiting refractory to antiemetics 1, 3
• Bleeding diathesis (uremic platelet dysfunction) 1, 3
• Pruritus unresponsive to medical management 1

Volume and Hemodynamic Complications

• Volume overload refractory to diuretic therapy (pulmonary edema, severe peripheral edema) 1, 3, 2
• Uncontrolled hypertension despite maximal medical management 1, 3, 2

Metabolic Derangements

• Severe metabolic acidosis (typically pH <7.2 or bicarbonate <10 mEq/L) unresponsive to oral alkali therapy 1, 3, 2
• Hyperkalemia (typically >6.5 mEq/L) unresponsive to medical therapy 1, 3, 2

Nutritional Deterioration

• Progressive deterioration in nutritional status refractory to dietary intervention 1, 2
• Protein-energy malnutrition that develops or persists despite vigorous nutritional optimization 1, 3, 2
• Declining edema-free body weight, falling serum albumin, or lean body mass <63% 2

Cognitive Impairment

• Cognitive impairment attributable to uremia 1

When Dialysis Can Be Safely Deferred

Dialysis may be deferred even when GFR <10 mL/min/1.73 m² if ALL of the following criteria are met: 2

• Stable or increased edema-free body weight 2
• Adequate nutritional parameters (stable albumin, adequate protein intake) 2
• Complete absence of clinical signs or symptoms attributable to uremia 2
• No metabolic derangements requiring urgent correction 2

Critical Measurement Considerations

Verify True Renal Function

• In patients with unusual creatinine generation or altered tubular secretion, obtain measured GFR using 24-hour urine collection for creatinine and urea clearance rather than relying on estimated GFR. 3, 2
• The MDRD equation may overestimate GFR at very low levels; when MDRD shows 15 mL/min/1.73 m², true GFR may be closer to 19.7 mL/min/1.73 m². 4
• For pediatric patients, GFR can be estimated using either timed urine collection or the Schwartz formula. 1

Initial Dialysis Prescription: "Low and Slow" Approach

When dialysis is indicated, the first treatment must use a cautious approach to minimize dialysis disequilibrium syndrome and hemodynamic instability: 3, 2

• Initial session duration: 2-2.5 hours (not full 4 hours) 3, 2
• Reduced blood flow rates: 200-250 mL/min 3, 2
• Minimal ultrafiltration during first session, focusing on clearance rather than fluid removal 3, 2
• Frequent vital sign monitoring every 15-30 minutes during the first session 3
• Close observation for neurological symptoms indicating dialysis disequilibrium 3
• Gradual dose escalation over subsequent sessions as tolerated 3, 2

Critical Pitfalls to Avoid

Do Not Initiate Based on GFR Alone

• Early dialysis initiation in asymptomatic patients provides no survival benefit and may cause harm. 2
• When corrected for lead-time bias, there is no survival advantage to starting dialysis at higher GFR levels. 2
• Observational data showing earlier initiation at higher GFR reflects patient selection bias (sicker patients start earlier) rather than benefit. 2

Recognize Dialysis-Related Risks

• Hemodialysis-related hypotension may accelerate loss of residual kidney function, which is particularly problematic in patients who may recover renal function. 3, 2, 5
• Dialysis does not replace all kidney functions and imposes significant burden on patients. 3, 2, 6
• Vascular access complications, dialysate-related complications, and cardiovascular disease remain major concerns. 2, 6

Avoid Aggressive First Sessions

• Rapid removal of uremic toxins can cause cerebral edema, seizures, and cardiovascular instability. 3
• Dialysis disequilibrium syndrome is preventable with appropriate initial prescription. 3

Special Populations

Pediatric Patients

• Dialysis initiation should follow adult guidelines of GFR <15 mL/min/1.73 m² 1
• Additional pediatric-specific indication: malnutrition or growth failure refractory to medication and dietary management 1
• Children should receive at least the delivered dialysis dose recommended for adults, with younger children requiring higher doses (150% protein intake). 1

Multidisciplinary Care

• Patients with progressive CKD should be managed in a multidisciplinary care setting that includes dietary counseling, education about RRT modalities, transplant options, vascular access surgery, and psychological/social care. 1