What is the recommended duration of night dwell in peritoneal dialysis (PD) initiation?

Night Dwell Duration in Peritoneal Dialysis Initiation

For patients initiating peritoneal dialysis (PD), a 9-hour night dwell is recommended for continuous cycling peritoneal dialysis (CCPD), while continuous ambulatory peritoneal dialysis (CAPD) should include an overnight dwell as part of the standard prescription to optimize middle-molecule clearance and volume control. 1

Initial PD Prescription Guidelines

For Patients with GFR < 2 mL/min:

• CAPD Prescription:

  • BSA < 1.7 m²: 2.0 L exchanges × 4/day
  • BSA 1.7-2.0 m²: 2.5 L exchanges × 4/day
  • BSA > 2.0 m²: 3.0 L exchanges × 4/day
  • One exchange should be overnight (typically 8-10 hours)

• CCPD Prescription:

  • BSA < 1.7 m²: 2.0 L (9 hours/night) + 2.0 L/day
  • BSA 1.7-2.0 m²: 2.5 L (9 hours/night) + 2.0 L/day
  • BSA > 2.0 m²: 3.0 L (9 hours/night) + 3.0 L/day 2

For Patients with GFR ≥ 2 mL/min:

• CAPD Prescription:

  • BSA < 1.7 m²: 2.5 L/day × 4 exchanges
  • BSA 1.7-2.0 m²: 3.0 L/day × 4 exchanges
  • BSA > 2.0 m²: 3.0 L/day × 4 exchanges

• CCPD Prescription:

  • BSA < 1.7 m²: 2.5 L (9 hours/night) + 2.0 L/day
  • BSA 1.7-2.0 m²: 3.0 L (9 hours/night) + 2.5 L/day
  • BSA > 2.0 m²: 3.0 L (10 hours/night) + 3.0 L/day 2

Rationale for Night Dwell Duration

1. Middle-molecule clearance: Night dwells are essential for removing middle-sized molecules, which is time-dependent rather than volume-dependent 1

2. Optimized ultrafiltration: The drain volume from overnight dwells should be monitored monthly to ensure adequate ultrafiltration and solute removal 2

3. Volume control: For patients with hypertension or volume overload, ultrafiltration should be positive for all exchanges, including the night dwell 2

4. Mortality and morbidity impact: Proper volume control through appropriate dwell times directly impacts patient survival and cardiovascular outcomes 1

Special Considerations

For Urgent-Start PD:

When initiating PD urgently (within 48 hours of catheter placement), begin with lower volumes during overnight automated PD and gradually increase to target volume over 2-3 weeks 3

For Patients with Different Transport Characteristics:

• High transporters: May benefit from shorter dwells to prevent fluid reabsorption; consider icodextrin for the long dwell 4
• Low transporters: Will require longer dwell times to achieve adequate solute clearance 2

Volume Optimization:

• Increase exchange volume before increasing exchange frequency to optimize clearance 2
• Start with increasing supine exchange volumes (night dwell) as this position has the lowest intra-abdominal pressure 2
• For children, use BSA-normalized volumes (at least 1,100 mL/m²) 2

Common Pitfalls to Avoid

1. Inadequate dwell time: Too short a night dwell can compromise middle-molecule clearance even if small-molecule clearance targets are met 1

2. Excessive dwell time with glucose-based solutions: Beyond 10 hours with glucose-based solutions, ultrafiltration may not significantly increase and may even decrease due to glucose absorption 5

3. Ignoring transport characteristics: Not adjusting dwell time based on peritoneal membrane transport characteristics can lead to suboptimal clearance and ultrafiltration 2

4. Neglecting volume status: Failing to monitor drain volumes from overnight dwells can lead to undetected volume overload 2

5. Starting with full-volume exchanges: When initiating PD soon after catheter placement, full-volume exchanges may increase the risk of leakage; low-volume, supine dialysis is recommended initially 2

By following these guidelines for night dwell duration in PD initiation, clinicians can optimize solute clearance, ultrafiltration, and volume control, which are critical factors affecting patient morbidity and mortality.