Peritoneal Dialysis Adequacy Calculator

This calculator estimates two of the standard adequacy measures used to judge whether a peritoneal dialysis (PD) prescription is clearing enough waste: total weekly Kt/V (a normalized measure of urea clearance) and weekly peritoneal creatinine clearance. Total weekly Kt/V is built from two components that are simply added together -- the peritoneal component, calculated from the dialysate-to-serum urea ratio times the daily drain volume (scaled to a week) and normalized to total body water estimated by the Watson formula, plus a residual renal component calculated the same way from any remaining urine output and urine urea. Residual native kidney function matters more than it might seem: even a modest amount of urine output can contribute meaningfully to total clearance, which is why the calculator asks for 24-hour urine volume and urine urea separately from the dialysate measurements. The weekly creatinine clearance figure, by contrast, reports the peritoneal component only -- computing a true total would also need a residual renal creatinine-clearance term (requiring urine and serum creatinine, not just urea), which this calculator doesn't collect, so don't compare this number directly to a total-CrCl target if you have meaningful residual renal function; the total would be higher.

KDOQI's 2006 guidance targeted a total weekly Kt/V of at least 1.7 for continuous ambulatory PD (CAPD) -- a target this calculator's helper text reflects -- but adequacy guidance has moved since then: ISPD's 2020 update explicitly moved away from a single fixed Kt/V number in favor of individualized, symptom- and volume-status-guided prescribing, and trials found that pushing weekly creatinine clearance well above the historical target added little additional survival benefit. Creatinine clearance targets in particular have varied across published guidance (older references cite figures in roughly the 50-60 L/week/1.73m² range, split by peritoneal transport type -- historically around 60 for high and high-average transporters versus 50 for low and low-average) and are now generally treated as a secondary, supporting metric rather than the primary adequacy target total Kt/V once was. The PET (peritoneal equilibration test) transport classification, from the dialysate-to-plasma creatinine ratio at 4 hours, groups patients as low, low-average, high-average, or high transporters, which in practice guides prescription choices like exchange frequency and dwell time rather than being an adequacy pass/fail marker on its own -- and it's also relevant to reading the weekly peritoneal CrCl figure, since the historical target for that number depends on transport type. Confirm current target values and interpretation with your dialysis unit's protocol, since practice varies and guidance continues to be refined.