The effect of small solute clearances on survival of anuric peritoneal dialysis patients

Objective: Primarily, to determine whether peritoneal small solute clearanc e is related to patient and technique survival among anuric peritoneal dial ysis [continuous ambulatory (CAPD) and automated peritoneal dialysis (APD)] patients. A secondary goal was to describe the ability to attain Dialysis Outcomes Quality Initiative (DOQI) targets among anuric patients on periton eal dialysis. Design: Retrospective cohort study via chart reviews. Setting: Peritoneal Dialysis Unit of Toronto Hospital (Western Division). Patients: The study included 122 CAPD and APD patients between January 1992 and September 1997, with 24-hour urine volume less than 100 mL, or renal c reatinine clearance (CCr) less than 1 mL/minute. Adequacy data were availab le for 115 patients. Outcome Measures: Mortality and technique failure (TF). Regression analysis was used to estimate the mortality and TF rate ratios (RR) for peritoneal Kt/V urea (pKt/V) and pCCr, adjusting for age, gender, diabetes, months of follow-up prior to anuria, albumin, transport status, coronary artery disea se, cardiovascular disease, and peripheral vascular disease. Results: Fifty seven per cent (51/89) of patients on CAPD and 81% (21/26) o n APD had a weekly pKt/V greater than or equal to 2 and greater than or equ al to 2.2, respectively (DOQI targets); whereas only 35% on CAPD (31/89) an d 35% (9/26) on APD had a weekly pCCr greater than or equal to 60 L/1.73 m( 2) and 66 L/1.73 m(2), respectively Median follow-up times among patients w ere 16.5 and 19.5 months pre- and postanuria, respectively. Patients with p Kt/V greater than or equal to 1.85 experienced a strong decrease in patient mortality (RR = 0.54, p = 0.10); the effect was less pronounced for pCCr g reater than or equal to 50 L/1.73 m(2) (RR = 0.63, p = 0.25). No relationsh ip was observed between pKt/V or pCCr and TF. Conclusion: Mortality was noticeably less frequent among patients with a pK t/V greater than or equal to 1.85 compared with those with a Kt/V < 1.85 (p = 0.10). Given the magnitude of the association, the failure to observe st atistical significance relates to the size of the patient cohort. Our resul ts imply that it is, in fact, possible to achieve DOQI targets among anuric patients on peritoneal dialysis.