Incremental Hemodialysis, Residual Kidney Function, and Mortality Risk in Incident Dialysis Patients: A Cohort Study

• Published in: American journal of kidney diseases Vol. 68; no. 2; pp. 256 - 265
• Main Authors: Obi, Yoshitsugu, MD, PhD, Streja, Elani, MPH, PhD, Rhee, Connie M., MD, MSc, Ravel, Vanessa, MPH, Amin, Alpesh N., MD, MBA, Cupisti, Adamasco, MD, Chen, Jing, MD, PhD, Mathew, Anna T., MD, MPH, Kovesdy, Csaba P., MD, Mehrotra, Rajnish, MD, Kalantar-Zadeh, Kamyar, MD, MPH, PhD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.08.2016
• Subjects: Aged; Cohort Studies; dialysis initiation; Female; frequent hemodialysis; Humans; Incremental hemodialysis; interdialytic weight gain; Kidney - physiopathology; Kidney Failure, Chronic - mortality; Kidney Failure, Chronic - physiopathology; Kidney Failure, Chronic - therapy; Longitudinal Studies; Male; Middle Aged; mortality; Nephrology; Renal Dialysis - methods; renal urea clearance; residual kidney function (RKF); Risk; standard Kt/V; treatment regimen; twice-weekly hemodialysis; residual kidney function (RKF); standard Kt/V; frequent hemodialysis; mortality; Incremental hemodialysis; dialysis initiation; twice-weekly hemodialysis; renal urea clearance; interdialytic weight gain; treatment regimen
• ISSN: 0272-6386; 1523-6838
• DOI: 10.1053/j.ajkd.2016.01.008

Background Maintenance hemodialysis is typically prescribed thrice weekly irrespective of a patient’s residual kidney function (RKF). We hypothesized that a less frequent schedule at hemodialysis therapy initiation is associated with greater preservation of RKF without compromising survival among patients with substantial RKF. Study Design A longitudinal cohort. Setting & Participants 23,645 patients who initiated maintenance hemodialysis therapy in a large dialysis organization in the United States (January 2007 to December 2010), had available RKF data during the first 91 days (or quarter) of dialysis, and survived the first year. Predictor Incremental (routine twice weekly for >6 continuous weeks during the first 91 days upon transition to dialysis) versus conventional (thrice weekly) hemodialysis regimens during the same time. Outcomes Changes in renal urea clearance and urine volume during 1 year after the first quarter and survival after the first year. Results Among 23,645 included patients, 51% had substantial renal urea clearance (≥3.0 mL/min/1.73 m2 ) at baseline. Compared with 8,068 patients with conventional hemodialysis regimens matched based on baseline renal urea clearance, urine volume, age, sex, diabetes, and central venous catheter use, 351 patients with incremental regimens exhibited 16% (95% CI, 5%-28%) and 15% (95% CI, 2%-30%) more preserved renal urea clearance and urine volume at the second quarter, respectively, which persisted across the following quarters. Incremental regimens showed higher mortality risk in patients with inadequate baseline renal urea clearance (≤3.0 mL/min/1.73 m2 ; HR, 1.61; 95% CI, 1.07-2.44), but not in those with higher baseline renal urea clearance (HR, 0.99; 95% CI, 0.76-1.28). Results were similar in a subgroup defined by baseline urine volume of 600 mL/d. Limitations Potential selection bias and wide CIs. Conclusions Among incident hemodialysis patients with substantial RKF, incremental hemodialysis may be a safe treatment regimen and is associated with greater preservation of RKF, whereas higher mortality is observed after the first year of dialysis in those with the lowest RKF. Clinical trials are needed to examine the safety and effectiveness of twice-weekly hemodialysis.