Registry or national dialysis data show that a sizeable proportion of contemporary dialysis patients have substantial levels of residual kidney function especially upon transitioning to dialysis therapy. However, among incident hemodialysis patients, the prevailing paradigm has been to initiate "full-dose" triweekly treatment schedules irrespective of native kidney function in most developed countries. Recognizing the benefits of residual kidney function upon the health and survival of dialysis patients, there has been growing interest in incremental hemodialysis, in which dialysis frequency and dose are tailored according to the degree of patients' residual kidney function. Infrequent hemodialysis can also be used for those who prefer a more conservative approach in managing uremia. Clinical practice guidelines support the use of twice-weekly hemodialysis among patients with adequate residual kidney function (renal urea clearance >3 mL/min/1.73 m2), and a growing body of evidence indicates that incremental hemodialysis is associated with better preservation of residual kidney function without adversely impacting survival. Nonetheless, incremental hemodialysis remains an underutilized approach in this population. In this review, we will discuss the history of the twice- versus triweekly hemodialysis schedules; current clinical practice guidelines regarding infrequent hemodialysis; emerging data on incremental treatment regimens and outcomes; and guidelines for the practical implementation of incremental and infrequent hemodialysis in the clinical setting.

Incremental hemodialysis has been examined as a viable hemodialysis regimen for selected end-stage renal disease (ESRD) patients. Preservation of residual kidney function (RKF) has been the driving impetus for this approach given its benefits upon the survival and quality of life of dialysis patients. While clinical practice guidelines recommend an incremental start of dialysis in peritoneal dialysis patients with substantial RKF, there remains little guidance with respect to incremental hemodialysis as an initial renal replacement therapy regimen. Indeed, several large population-based studies suggest that incremental twice-weekly vs. conventional thrice-weekly hemodialysis has favorable impact upon RKF trajectory and survival among patients with adequate renal urea clearance and/or urine output. In this report, we describe a case series of 13 ambulatory incident ESRD patients enrolled in a university-based center's Incremental Hemodialysis Program over the period of January 2015 to August 2016 and followed through December 2016. Among five patients who maintained a twice-weekly hemodialysis schedule vs. eight patients who transitioned to thrice-weekly hemodialysis, we describe and compare patients' longitudinal case-mix, laboratory, and dialysis treatment characteristics over time. The University of California Irvine Experience is the first systemically examined twice-weekly hemodialysis practice in North America. While future studies are needed to refine the optimal approaches and the ideal patient population for implementation of incremental hemodialysis, our case-series serves as a first report of this innovative management strategy among incident ESRD patients with substantial RKF, and a template for implementation of this regimen.