Questions About PD
Dwell time should be adapted to every patient to achieve adequate dialysis, taking into account several factors, including the type of osmotic agent (icodextrin-based dialysis solutions requiring dwell times of >6 hours, ideally 8-12 hours), catheter patency (which influences duration of drainage) and membrane function (mainly peritoneal solute transport rate, which is best evaluated using the dialysate-over-plasma creatinine ratio at the end of the 4h-PET).
Short dwell times are typically prescribed in patients with high PSTR (fast transport status), to optimize glucose-driven ultrafiltration using automated PD.
While there is no consensual definition of the minimal dwell time, decreasing dwell time below (60-) 80 minutes does not provide any additional benefit – as transport of water and solutes (incl. sodium) takes some time to occur, and as infusion and drainage times should also be considered. In addition, very short dwell times promote free-water transport rather than solute-coupled (ie sodium) water transport, therefore failing to restore euvolemia in fluid overloaded patients with a high PSTR.