What are the guidelines for initiating and managing effective hemodialysis?

Effective Hemodialysis: Initiation and Management Guidelines

Initiate hemodialysis when GFR falls below 10 mL/min/1.73 m² or when uremic symptoms develop, whichever comes first, using a permanent vascular access (preferably native AV fistula) and targeting a minimum delivered Kt/V of 1.2 with treatment time of at least 3-4 hours per session, three times weekly. 1

Timing of Hemodialysis Initiation

GFR-Based Thresholds

• Target GFR for initiation: approximately 10 mL/min/1.73 m² 1
• Conservative management should continue until GFR decreases to less than 15 mL/min/1.73 m², unless specific indications exist 1
• Young and middle-aged adults typically initiate at GFR 7-9 mL/min/1.73 m², while children and elderly patients initiate at 10-10.5 mL/min/1.73 m² 1
• Critical caveat: No clear survival advantage exists for starting dialysis earlier when correcting for lead-time bias 1

Clinical Indications That Override GFR Thresholds

Initiate dialysis earlier (GFR >10 mL/min/1.73 m²) when patients develop: 1

• Malnutrition or declining nutritional status
• Fluid overload refractory to diuretics
• Uremic bleeding or serositis
• Peripheral neuropathy
• Cognitive impairment from uremia
• Severe metabolic acidosis
• Hyperkalemia unresponsive to medical management

Pre-Dialysis Preparation (Stage 4 CKD)

Begin planning when patients reach CKD stage 4 (GFR 15-29 mL/min/1.73 m²) to allow: 1

• Patient education about treatment modalities (minimum 3-6 months before anticipated start)
• Vascular access creation with adequate maturation time (native AV fistula requires 2-4 months)
• Evaluation for preemptive kidney transplantation
• Training for home dialysis if selected

Vascular Access Strategy

Access Type Priority

Native AV fistulae are the mandatory first choice, demonstrating superior 4-5 year patency rates and requiring fewest interventions compared to synthetic grafts or catheters 2

• Synthetic AV grafts only when native fistulae are anatomically impossible 2
• Central venous catheters reserved for urgent dialysis initiation or bridge therapy only

Access Monitoring Requirements

Implement systematic surveillance at every dialysis session: 2

• Assess adequacy of blood flow rates
• Monitor for access recirculation (reduces dialyzer concentration gradient)
• Evaluate for hemodynamically significant stenosis
• Check for pseudoaneurysm development in grafts
• Document findings in quality database

Critical pitfall: Avoid needle insertion into pseudoaneurysm areas; surgical intervention required when rapid expansion occurs, size exceeds twice graft diameter, overlying skin threatened, or infection present 2

Dialysis Dose Prescription

Minimum Adequacy Targets

• Delivered Kt/V: minimum 1.2 per session (not target—this is the floor) 1
• URR (Urea Reduction Ratio): minimum 65% 1
• Treatment time: 3-4 hours per session, three times weekly 1
• Blood flow rate: 300-450 mL/min (patient-dependent)
• Dialysate flow rate: 500-800 mL/min 1

Warning: Deliberately targeting minimum values (Kt/V 1.2 or URR 65%) results in significant number of sessions falling below adequacy thresholds due to multiple variables that adversely affect delivered dose 1

Common Factors Compromising Delivered Dose

Access-Related Problems

• Access recirculation reduces concentration gradient in dialyzer 1, 2
• Inadequate blood flow from vascular access stenosis 1, 2
• High pre-pump extracorporeal negative pressure 1

Equipment and Technical Issues

• Dialyzer clotting reduces effective surface area 1, 2
• Blood pump or dialysate flow miscalibration 1
• Dialyzer leaks 1
• Dialysate flow rate set inappropriately low 1

Treatment Time Reductions

Effective treatment time must reflect exact duration of diffusion at prescribed flow rates: 1, 2

• Interruptions for clinical complications during session
• Equipment alarms requiring pump stoppage
• Fistula needle manipulation or replacement
• Premature discontinuation for staff convenience or patient request
• Patient tardiness delaying session initiation
• Incorrect time documentation (use synchronized dialysis unit clock, not wristwatches) 1

Laboratory Sampling Errors

Pre-dialysis BUN sampling errors: 1

• Dilution with saline (falsely lowers BUN, increases apparent V)
• Drawing sample after dialysis starts (BUN already lowered)
• Laboratory calibration problems

Post-dialysis BUN sampling errors: 1

• Drawing before dialysis ends (falsely elevates BUN)
• Drawing >5 minutes after dialysis (urea rebound increases BUN)

Dialysate Composition Optimization

Sodium Management

• Time-averaged dialysate sodium concentration (TACNa) should be 0.5-0.8 mmol/L lower than patient's pre-dialysis serum sodium to achieve sodium-neutral dialysis 3
• Optimal TACNa range: 137.8-143.5 mmol/L for most patients 3
• Hypernatric dialysis risks positive sodium balance, worsening thirst, and hypertension 4
• Hyponatric dialysis may cause negative sodium balance, cardiovascular instability, and disequilibrium symptoms 4

Bicarbonate Buffering

• Personalize bicarbonate concentration to achieve midweek pre-dialysis serum bicarbonate of 22 mmol/L 4

Potassium Profiling

• Implement potassium profiling with constant gradient between plasma and dialysate to minimize arrhythmogenic potential 4

Calcium Considerations

• Increase dialysate calcium concentration in cardiac-compromised, hypotension-prone patients (improves myocardial contractility and peripheral vascular resistance) 4

Prevention of Dialysis Disequilibrium Syndrome

High-Risk Patients

Patients with advanced uremia (BUN ≥200 mg/dL) or initiating dialysis after prolonged interval require structured protocol: 5

First dialysis session protocol: 5, 6

• Target URR 20-30% (not standard 65%)
• Shorter session duration (2-2.5 hours maximum)
• Linear dialysate sodium profiling with higher sodium concentration 5, 6
• Prophylactic mannitol administration 5
• Prophylactic 25% dextrose administration 5

Subsequent sessions: 5

• Second session: target URR ~35%
• Third session: target URR ~34%
• Gradually increase to standard adequacy targets by fourth session

This structured approach reduces DDS incidence to 4% with severe DDS only 2% 5

Intradialytic Hypotension Management

Systematic approach to prevent and treat hypotension: 2, 7

• Avoid excessive ultrafiltration rates (limit to <13 mL/kg/hour)
• Slow ultrafiltration rate when hypotension develops
• Perform isolated ultrafiltration if needed
• Increase dialysate sodium concentration (within safe range)
• Switch from acetate to bicarbonate-buffered dialysate
• Reduce dialysate temperature
• Administer midodrine pre-dialysis
• Correct anemia to recommended ranges
• Administer supplemental oxygen if indicated 2

Emergency Management: Loss of Consciousness During Dialysis

Immediate action sequence (0-2 minutes): 7

1. Stop dialysis immediately
2. Place patient in Trendelenburg position
3. Assess airway/breathing/circulation
4. Apply AED pads if pulseless
5. Initiate CPR if indicated

Systematic evaluation (2-5 minutes): 7

• Check fingerstick glucose immediately
• Obtain vital signs
• Perform focused neurological examination
• Consider cardiac arrhythmias from electrolyte shifts (potassium, calcium) 7
• Consider severe hypotension from excessive ultrafiltration 7
• Consider dialysis disequilibrium syndrome in new patients 7

Critical fact: Dialysis units experience cardiac arrest at 7 events per 100,000 sessions, with 61% of cardiac deaths attributed to arrhythmic mechanisms; bystander CPR combined with rapid defibrillation achieves 38% survival in ventricular fibrillation/ventricular tachycardia cases 7, 8

Quality Assurance Requirements

Mandatory Monitoring Programs

Every dialysis center must implement: 2

• Comprehensive database tracking access types, complication rates, and outcomes
• Regular clinical assessment to detect access dysfunction before thrombosis
• Documentation of all access-related hospitalizations
• Monitoring of access patency rates by type
• Documentation of all interventions required to maintain patency
• Staff and patient education programs on access care

Patient Re-evaluation

• Re-evaluate for possible native AV fistula construction after every dialysis access failure 2