Comparison of characteristics of centers practicing incremental vs. conventional approaches to hemodialysis delivery - postdialysis recovery time and patient survival.

INTRODUCTION: Conventional haemodialysis (HD) involves treatment times of around 4 hours thrice weekly, taking no account of residual kidney function (RKF). In incremental HD the frequency and duration of dialysis sessions are individualized according to RKF. There are no studies comparing these approaches. We utilized data from a recent multicenter study to compare patient characteristics and outcomes between a center practicing incremental HD and others using a conventional approach.

METHODS: Seven hundred and nine patients attending for routine outpatient HD in five UK centers were studied. One center practiced incremental dialysis (n = 254) and four conventional HD (n = 455). Data collected included demographics, comorbidity, dialysis parameters, routine biochemistry and hematology, recovery time postdialysis, and Beck Depression Inventory-II score (BDI-II). Patients were followed for a minimum of 12 months.

FINDINGS: Pre- and postdialysis BP, serum calcium and phosphate were higher in the incremental center, whilst sessional Kt/Vurea was lower (all P < 0.001), as was the proportion of patients with a mean postdialysis BP <100 mmHg (P = 0.011). Patients recovered from their HD session more quickly in the incremental center, with significantly more patients reporting recovery within 1 and 4 hours Short-term survival was significantly better in the incremental center both unadjusted and adjusted for age, gender, ethnicity, dialysis vintage, anuria, history of cancer, heart disease, diabetes mellitus, body mass index, serum albumin, BDI-II score, and sessional Kt/V.

DISCUSSION: The association between incremental dialysis, shorter postdialysis recovery times and improved short-term survival may be related to reduced haemodynamic stress as a consequence of less intensive ultrafiltration and reduced length of dialysis sessions. Prospective studies are required to test this hypothesis.