Optimizing Peritoneal Dialysis Dwell Time

Core Principles

The American Journal of Kidney Diseases recommends that peritoneal dialysis should include dwells for the majority of the 24-hour day to maximize middle-molecule clearance, even when small-molecule clearance targets are already met, for optimal patient outcomes 1, 2
Overnight dwells require particular monitoring attention as these exchanges are critical for optimizing both solute clearance and ultrafiltration volume, according to the American Journal of Kidney Diseases 1, 2
Daytime dwell volumes must be monitored monthly as these are essential for maintaining adequate clearance and ultrafiltration, as stated by the American Journal of Kidney Diseases 1, 2

Nightly Intermittent Peritoneal Dialysis (NIPD) can be considered in pediatric patients who are clinically well and whose combined prescription plus residual kidney function exceeds target clearance without evidence of hyperphosphatemia, hyperkalemia, hypervolemia, or acidosis, as recommended by the American Journal of Kidney Diseases 3

Prescriptions should preferentially include dwells for the majority of the 24-hour day in patients with minimal residual kidney function to prioritize middle-molecule clearance, according to the American Journal of Kidney Diseases 1, 2
This recommendation applies even when small-molecule clearance is above target without the longer dwell, as stated by the American Journal of Kidney Diseases 1, 2
Middle-molecule clearance is time-dependent and not significantly influenced by dialysate flow rates or dwell volumes, as reported by the American Journal of Kidney Diseases 2
Increase instilled volume per exchange first (target 1,000-1,200 mL/m² BSA, maximum 1,400 mL/m²) before increasing the number of exchanges to optimize small-solute clearance, as recommended by the American Journal of Kidney Diseases 1, 3
Increase supine exchange volumes first as this position has the lowest intra-abdominal pressure to optimize small-solute clearance, according to the American Journal of Kidney Diseases 1, 2

Review PD effluent volume records monthly with particular attention to drain volumes from overnight dwells in CAPD and daytime dwells in APD, as recommended by the American Journal of Kidney Diseases 1, 2
Optimize drain volume during these key dwells to maximize both solute clearance and ultrafiltration, according to the American Journal of Kidney Diseases 1, 2
Obtain baseline peritoneal membrane transport study 4-8 weeks after starting dialysis to guide prescription management, as stated by the American Journal of Kidney Diseases 4
Repeat testing when clinically indicated, particularly if ultrafiltration failure is suspected, as recommended by the American Journal of Kidney Diseases 4

Patient schedule and quality of life must be considered as nonadherence is more common with demanding prescriptions like CAPD with 5 exchanges daily, according to the American Journal of Kidney Diseases 1, 2

The American Journal of Kidney Diseases recommends Continuous Ambulatory Peritoneal Dialysis (CAPD) which operates 24/7 with fluid continuously dwelling in the peritoneal cavity 5, 6
Automated Peritoneal Dialysis (APD) also runs 24 hours daily but concentrates exchanges during nighttime hours, with a cycling machine performing exchanges overnight, typically 9-10 hours per night 7, 8, 9, 10
Approximately 85% of APD patients require one or more daytime dwells in addition to nighttime cycling to achieve adequate clearance, as suggested by the American Journal of Kidney Diseases 5, 7, 9
Nightly Intermittent Peritoneal Dialysis (NIPD) is reserved for specific patient populations, such as high/rapid transporters with significant residual kidney function, and performs exchanges only during nighttime hours without daytime dwells 9, 10

Peritoneal dialysis provides continuous renal replacement therapy throughout the entire week, delivering dialysis 168 hours per week, as stated by Clinical Nutrition 11
The weekly clearance targets (Kt/V ≥2.0) account for this continuous treatment schedule, according to the American Journal of Kidney Diseases 5, 12