Long-term experience with an ultrapure individual dialysis fluid with a batch type machine

Background. This paper discusses long-term experience with a specific type of dialysis equipment which has been used more than 15 years without variation. The system was designed to allow easy individualization of dialysis fluid composition and to deliver dialysate of the highest hygienic quality. Methods. Data from 399 patients covering the period from 1971 onwards were analysed retrospectively. Survival probabilities were estimated by the Kaplan-Meier method and the median number of days in hospital was calculated. Additional data collected from patient subgroups included serum albumin level, erythropoietin requirement and antihypertensive treatments. Kt/V and PCR from one subgroup were computed using the formulae of Daugirdas and Depner. Results, The estimated survival probability after 5 years for all patients was 59.1% (95% CI: 52.6-65.6%). The main risk factors from the available covariables were age and IDDM. The cumulative incidence of carpal tunnel syndrome after 10 years of dialysis was estimated as 7% (95% CI: 0-14%). Data from the subgroups revealed that 82% of the patients had serum albumin levels >4.0 g/dl, 65% of the patients received no antihypertensive drugs and 39% received erythropoietin (37+/-28 units/kg bw/week) to correct dialysis anaemia (haemoglobin level = 98 +/- 8 g/l). Average Kt/V was 1.21 +/- 0.17, PCR was 1.10 +/- 0.22 g/kg/day. Conclusions. The setup described permits individualized therapy of high quality. The high serum albumin values and our very low incidence of carpal tunnel syndrome underline the importance of water and dialysate quality.