Questions About PD
Thank you for your question.
If I understand correctly the situation of your patient (average fast PSTR), daily net UF is -200 to -500 ml – implying she/he reabsorbs this amount of fluid into the organism – yet he remains euvolemic thanks to significant residual kidney function.
The goals of PD are to achieve euvolemia and restore wellbeing, and having a negative UF is not a problem per se. It should therefore not motivate any change in prescription – provided the goals are achieved (incl. adequate volemic status, blood pressure control, electrolyte and acid-base control…).
That being said, it would be interesting to understand the reason for negative UF in your patient, i.e. as residual urine volume may decline over time on PD, and to minimize fluid/sodium absorption. First step is to rule out mechanical problems (catheter dysfunction/poor drainage or fluid sequestration): this can be suggested by a negative UF after icodextrin dwell, and/or insufficient drainage after in/out procedure with conventional PD fluid. Second, make sure there is no membrane dysfunction (low UF – fast transport status – low sodium sieving/sodium dip?). Lastly, you may consider to adapt PD prescription based on the average/fast PSTR of your patient – to shorten the duration of glucose-based dwells, and/or to use icodextrin for the long dwell, especially if your patient has overt fluid overload or if you suspect infraclinical fluid overload.
New, updated ISPD guidelines on membrane transport (incl. implications for peritoneal prescription) are currently under revision and will be released soon in Peritoneal Dialysis International. In the meantime, you can refer to:
- Mujais S, Nolph K, Gokal R, Blake P, Burkart J, Coles G, Kawaguchi Y, Kawanishi H, Korbet S, Krediet R, Lindholm B, Oreopoulos D, Rippe B, Selgas R. Evaluation and management of ultrafiltration problems in peritoneal dialysis. International Society for Peritoneal Dialysis Ad Hoc Committee on Ultrafiltration Management in Peritoneal Dialysis. Perit Dial Int. 2000;20 Suppl 4:S5-21. PMID: 11098926.
- van Biesen W, Heimburger O, Krediet R, Rippe B, La Milia V, Covic A, Vanholder R; ERBP working group on peritoneal dialysis. Evaluation of peritoneal membrane characteristics: clinical advice for prescription management by the ERBP working group. Nephrol Dial Transplant. 2010 Jul;25(7):2052-62. doi: 10.1093/ndt/gfq100. Epub 2010 Mar 4. PMID: 20203287.
Hope it helps! Best wishes