Intermittent peritoneal dialysis: urea kinetic modeling and implications of residual kidney function
Peritoneal dialysis international : journal of the International Society for Peritoneal Dialysis
BACKGROUND: Intermittent peritoneal dialysis (IPD) is an old strategy that has generally been eclipsed, in the home setting, by daily peritoneal therapies. However, for a select group of patients with exhausted vascular access or inability to receive PD at home, in-center IPD may remain an option or may serve as an incremental strategy before initiation of full-dose PD. We investigated the residual kidney clearance requirements necessary to allow thrice-weekly IPD regimens to meet current adequacy targets. METHODS: The 3-pore model of peritoneal transport was used to examine 2 thrice-weekly IPD dialysis modalities: 5 - 6 dwells with 10 - 12 L total volume (low-dose IPD), and 50% tidal with 20 - 24 L total volume (high-dose IPD). We assumed an 8-hour dialysis duration and 1.5% dextrose solution, with a 2-L fill volume, except in tidal mode. The PD Adequest application (version 2.0: Baxter Healthcare Corporation, Deerfield, IL, USA) and typical patient kinetic parameters derived from a large dataset [data on file from Treatment Adequacy Review for Gaining Enhanced Therapy (Baxter Healthcare Corporation)] were used to model urea clearances. The minimum glomerular filtration rate (GFR) required to achieve a total weekly urea Kt/V of 1.7 was calculated. RESULTS: In the absence of any dialysis, the minimum residual GFR necessary to achieve a weekly urea Kt/V of 1.7 was 9.7 mL/min/1.73 m(2). Depending on membrane transport type, the low-dose IPD modality met urea clearance targets for patients with a GFR between 6.0 mL/min/1.73 m(2) and 7.6 mL/min/1.73 m(2). Similarly, the high-dose IPD modality met the urea clearance target for patients with a GFR between 4.7 mL/min/1.73 m(2) and 6.5 mL/min/1.73 m(2). CONCLUSIONS: In patients with residual GFR of at least 7.6 mL/min/1.73 m(2), thrice-weekly low-dose IPD (10 L) achieved a Kt/V urea of 1.7 across all transport types. Increasing the IPD volume resulted in a decreased residual GFR requirement of 4.7 mL/min/1.73 m(2) (24 L, 50% tidal). In patients with residual kidney function and dietary compliance, IPD may be a viable strategy in certain clinical situations.
Guest, S., Akonur, A., Ghaffari, A., Sloand, J., & Leypoldt, J. K. (2012). Intermittent peritoneal dialysis: urea kinetic modeling and implications of residual kidney function. Peritoneal dialysis international : journal of the International Society for Peritoneal Dialysis, 32 (2). http://dx.doi.org/10.3747/pdi.2011.00027