No abstract

No abstract

Background Most hemodialysis patients worldwide are treated with bicarbonate dialysis using sodium bicarbonate as the base. Few studies have assessed outcomes of patients treated with different dialysate bicarbonate levels, and the optimal concentration remains uncertain. Study Design The Dialysis Outcomes and Practice Patterns Study (DOPPS) is an international prospective cohort study. Setting & Participants This study included 17,031 patients receiving thrice-weekly in-center hemodialysis from 11 DOPPS countries (2002–2011). Predictor Dialysate bicarbonate. Outcomes All-cause and cause-specific mortality and first hospitalization, using Cox regression to estimate the effects of dialysate bicarbonate concentration, adjusting for potential confounders. Measurements Demographics, comorbid conditions, laboratory values, and prescriptions were abstracted from medical records. Results Mean dialysate bicarbonate was 35.5 ± 2.7 (SD) mEq/L, ranging from 32.2 ± 2.3 mEq/L in Germany to 37.0 ± 2.6 mEq/L in the US. Prescription of high dialysate bicarbonate (≥38 mEq/L) was most common in the US (45% of patients). Approximately 50% of DOPPS facilities used a single dialysate bicarbonate concentration. 3,913 patients (23%) died during follow-up. Dialysate bicarbonate concentration was positively associated with mortality (adjusted HR, 1.08 per 4 mEq/L higher [95% CI, 1.01–1.15]; HR for dialysate bicarbonate ≥38 vs. 33–37 mEq/L, 1.07 [95% CI, 0.97–1.19]). Results were consistent across levels of pre-dialysis session serum bicarbonate and between facilities that used a single dialysate bicarbonate concentration and those that prescribed different concentrations to individual patients. The association of dialysis bicarbonate with mortality was stronger in patients with longer dialysis vintage. Limitations Due to the observational nature of the current study, we cannot rule out that the reported associations may be biased by unmeasured confounders. Conclusions High dialysate bicarbonate, especially prolonged exposure, may contribute to adverse outcomes, likely through development of post-dialysis metabolic alkalosis. Additional studies are warranted to identify the optimal dialysate bicarbonate concentration.

No abstract

SummaryBackground and objectives Sudden death is common in hemodialysis patients, but whether modifiable practices affect the risk of sudden death remains unclear.Design, setting, participants, & measurements This study analyzed 37,765 participants in 12 countries in the Dialysis Outcomes and Practice Patterns Study to explore the association of the following practices with sudden death (due to cardiac arrhythmia, cardiac arrest, and/or hyperkalemia): treatment time [TT] ,210 minutes, Kt/V ,1.2, ultrafiltration volume .5.7% of postdialysis weight, low dialysate potassium [K D ,3]), and prescription of Q wave/T wave interval-prolonging drugs. Cox regression was used to estimate effects on mortality, adjusting for potential confounders. An instrumental variable approach was used to further control for unmeasured patient-level confounding.Results There were 9046 deaths, 26% of which were sudden (crude mortality rate, 15.3/100 patient-years; median follow-up, 1.59 years). Associations with sudden death included hazard ratios of 1.13 for short TT, 1.15 for large ultrafiltration volume, and 1.10 for low Kt/V. Compared with K D $3 mEq/L, the sudden death rate was higher for K D #1.5 and K D =2-2.5 mEq/L. The instrumental variable approach yielded generally consistent findings. The sudden death rate was elevated for patients taking amiodarone, but not other Q wave/T wave interval-prolonging drugs.Conclusions This study identified modifiable dialysis practices associated with higher risk of sudden death, including short TT, large ultrafiltration volume, and low K D . Because K D ,3 mEq/L is common and easy to change, K D tailoring may prevent some sudden deaths. This hypothesis merits testing in clinical trials.