Disconnect during Continuous Ambulatory Peritoneal Dialysis (CAPD): Retrospective Experience with Three Different Systems

Disadvantages of continuous ambulatory peritoneal dialysis (CAPD), such as inconvenience and bulkiness of the apparatus, inflexibility of infusion volume, and predictable peritonitis incidence may be altered by using systems which allow disconnection from the tubing and bag after each exchange. At University of Michigan we have followed 35 patients using the O set@ with sodium hypochlorite (Baxter Healthcare Corp.) for 15.5 ± 10 months, 16 patients using the Y configuration Ultraset® (Baxter Healthcare Corp.) for 8.1 ± 5 months, and 6 patients using a universal adapter (Delmed Corp.) for 14.3 ± 7 months. Failure occurred in 7 cases (18%) at 12 ± 8 months using the O set (3 elective, 3 related to peritonitis, 1 ultrafiltration difficulty), and 1 (7%) at 3 months using the Ultraset (related to peritonitis). Accidental sodium hypochlorite infusion occurred 8 times in 6 patients, 4 patients still on CAPD without residual effect and 2 in whom infusion contributed to failure but not to ultrafiltration difficulty. Cumulative per-patient-year (episode/ months) peritonitis rates of 0.75 (1/16.4), 0.65 (1/18.4) and 0.88 (1/14.3), respectively, compare favorably with the overall center experience of 0.96 (1/12.2) (NIH-CAPD Registry). Peritonitis rates did not differ during use of any of the disconnect systems between patients with prior CAPD experience compared to patients without prior CAPD experience. More important, however, in patients with prior CAPD experience, peritonitis rates after initiation of the disconnect system tended to be lower than rates before disconnect with both the O set, 0.66 (1/18.1) vs. 1.18 (1/10.2) (n = 16, p < 0.09) and Ultraset, 0.46 (1/26.1) vs. 1.54 (1/7.9) (n = 6, p < 0.03), with insufficient data (n = 2) for the universal set. In conclusion, disconnect systems favorably influence not only patient preference for CAPD and ability to vary CAPD infusion volume, but also the frequency of peritonitis during long term use.