PRESCRIPTION AND ASSESSMENT OF TIDAL PERITONEAL-DIALYSIS DELIVERY WITH A SPECIFIC EQUILIBRATION TEST

Objective: To propose a simplified equilibration test specific for tid al peritoneal dialysis (TPD) that will overcome the inconveniences of the measurement of TPD peritoneal solute clearances through whole dial ysate collection. This will enable the prediction of peritoneal creati nine and urea clearances, the suitability of patients for TPD, and rou tine assessment of TPD delivery. Design:ln a prospective study, patien ts had a standardized TPD run, and dialysate-to-plasma (D/P) ratios fo r creatinine and urea were calculated at various TPD and peritoneal eq uilibration test (PET) time points and on total TPD dialysate. Solute clearances were estimated and measured, and correlation coefficients w ere obtained among all these variables. Setting: Dialysis unit of a pe diatric nephrology department and patients' homes. Patients: Eleven pe diatric patients with end-stage renal disease in stable clinical condi tions treated with TPD. Interventions:Dialysate and blood sample colle ctions. Main Outcome Measures: D/P ratios for creatinine and urea at t he fifth and seventh TPD exchanges, at 15-, 30-, 60-, and 120-minute P ET times, and on total TPD dialysate and TPD peritoneal creatinine and urea clearances. Results:Correlation coefficients between PET-derived and total TPD dialysate-derived D/P ratios, and those between PET-der ived and measured creatinine and urea clearances were more significant at the 120-minute PET time point compared with the other PET time poi nts. Best correlations were obtained at the fifth and seventh TPD exch anges. D/P ratios for creatinine and urea of the fifth and seventh TPD exchanges correlated significantly with the D/P ratios calculated fro m total TPD dialysate. A significant correlation was also found betwee n peritoneal creatinine and urea clearances on total dialysate volume (measured clearances) and those derived from the dialysate collection of the fifth and seventh TPD exchanges (estimated clearances) - that b ased on the seventh exchange being slightly more significant. Moreover , the estimated clearances derived from the seventh exchange were with in 10% of the measured value in 90.9% of patients both for creatinine and urea. Conclusion:The significant correlation between measured and estimated peritoneal creatinine and urea clearances and the low percen tage of underestimates of measured clearances obtained using the seven th TPD exchange-derived indices confirm the accuracy of the D/P ratios for creatinine and urea derived from any exchange after the fifth (pr eferably the seventh) of a standardized TPD run in estimating peritone al creatinine and urea clearances. This method could represent a simpl e and accurate means for prescribing TPD and routinely assessing TPD d elivery.