Optimization of Fill Volumes in Automated Peritoneal Dialysis

Abstract

Cyclers allow the prescription of fill volumes that vary between 50 mL and 3000 mL, in increments of 10 mL. The ability to customize the fill volume in automated peritoneal dialysis (APD) should optimize the treatment, provided that the correct volume is chosen. However, choosing the correct fill volume is not always easy. The prescription of large intraperitoneal volumes (IPVs) increases the efficiency of peritoneal mass transfer of solutes, but can reduce net ultrafiltration by increasing intraperitoneal hydrostatic pressure (IPP). In addition, a large IPV is not always well tolerated. This intolerance—in the supine position, which is characteristic of the treatment—is sometimes difficult to determine through simple questioning. The prescription of the IPV should then fulfill a double objective: permit efficient dialysis while avoiding the undesirable consequences of distention of the peritoneal cavity. Unlike continuous ambulatory peritoneal dialysis (CAPD), APD permits a greater number of nocturnal cycles without additional constraints for the patient. For the same total volume of dialysate, the possible advantage of modalities that use longer cycles with larger fill volumes should be compared to modalities that use shorter cycles with smaller fill volumes.