What are the indications for initiating hemodialysis and what is the standard procedure for performing it?

Hemodialysis Indications and Procedure

When to Initiate Hemodialysis

Initiate hemodialysis based on clinical symptoms and signs of uremia rather than GFR alone, typically when GFR falls between 5-10 mL/min/1.73 m² AND uremic manifestations are present. 1, 2

Absolute Indications for Dialysis Initiation

Start hemodialysis immediately when any of these life-threatening conditions are present:

• Uremic symptoms/signs: Pericarditis (serositis), seizures, altered mental status, intractable nausea/vomiting, uremic encephalopathy 1, 2
• Refractory volume overload: Pulmonary edema unresponsive to diuretics 1, 2
• Refractory hyperkalemia: Despite medical management 1
• Severe metabolic acidosis: Uncontrolled by bicarbonate therapy 1, 2
• Progressive malnutrition: Deteriorating nutritional status despite dietary intervention 1, 2

GFR Considerations

While GFR provides context, do not use GFR as the sole criterion for dialysis initiation 3:

• Conservative management is appropriate until GFR <15 mL/min/1.73 m² unless specific indications exist 3
• Theoretical optimal initiation occurs around GFR 10 mL/min/1.73 m² 3, 4, 3
• No survival advantage exists for early dialysis initiation (starting at higher GFR) when corrected for lead-time bias 3
• Patients with significant comorbidities often start at higher GFR due to earlier symptom development 3

Critical caveat: Research shows patients initiating dialysis for volume overload have 1.69 times higher mortality risk compared to those starting for laboratory decline alone 5. This underscores the importance of aggressive pre-dialysis management of volume status.

Uremic Signs and Symptoms to Monitor

Watch for these manifestations indicating need for dialysis 1:

Neurological: Seizures, cognitive impairment, somnolence, altered seizure threshold
Cardiovascular: Pericarditis, refractory hypertension
Gastrointestinal: Intractable nausea/vomiting, anorexia
Metabolic: Protein-energy wasting, heightened catabolism
Other: Intractable pruritus, platelet dysfunction, hiccups

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Standard Hemodialysis Procedure

Frequency and Duration

Prescribe hemodialysis three times per week as the standard regimen 6:

• Twice-weekly dialysis is inadequate unless residual kidney function (GFR) ≥5 mL/min with close monitoring 6
• If starting twice-weekly due to preserved residual function, monitor serially and transition to thrice-weekly as kidney function declines 6

Dialysis Dose Prescription

Prescribe a target Kt/V of 1.3 (corresponding to URR ~70%) to ensure delivered dose meets the minimum adequate level 6:

The prescribed dose must exceed the minimum because actual delivered dose frequently falls short due to:

Clearance compromises:

• Access recirculation reducing concentration gradient
• Inadequate blood flow from vascular access
• Dialyzer performance below manufacturer specifications
• Dialyzer clotting during treatment
• Blood pump/dialysate flow calibration errors 6

Treatment time reductions:

• Interruptions for clinical complications
• Equipment alarms and malfunctions
• Premature discontinuation (patient request or staff convenience)
• Patient tardiness 6

Sampling errors:

• Predialysis BUN diluted with saline
• Postdialysis sample drawn too early or too late (>5 minutes causes urea rebound)
• Laboratory calibration problems 6

Alternative Hemodialysis Regimens

In-center short frequent HD (>3 sessions/week): Consider as alternative to conventional thrice-weekly, but inform patients of increased vascular access complications and hypotension risk 1

Home long HD (6-8 hours, 3-6 nights/week): Offer for lifestyle considerations, with counseling about increased access complications, caregiver burden, and potential accelerated loss of residual kidney function 1

Pregnancy: Prescribe long frequent hemodialysis (in-center or home) for pregnant women with ESRD 1

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Critical Procedural Considerations

Beyond Kt/V Targets

Do not base dialysis adequacy solely on Kt/V or URR 6:

Even with adequate Kt/V, patients may be inadequately dialyzed regarding:

• Potassium removal
• Correction of acidosis
• Adequate nutrition/protein intake
• Volume removal to achieve euvolemia 6

Shared Decision-Making

Dialysis duration should involve shared decision-making with patients 6. After full disclosure of consequences of inadequate dialysis, respect patient wishes while maintaining non-confrontational dialogue. Address correctable barriers like cramps or hypotension 6.

Monitoring Requirements

Measure delivered dialysis dose regularly to ensure prescribed targets are met, as studies show only 50% of patients receive their prescribed dose 6.