Facility Dialysate Calcium Practices and Clinical Outcomes Among Patients Receiving Hemodialysis: A Retrospective Observational Study.

Abstract

BACKGROUND:

Some US dialysis facilities have reduced default dialysate calcium concentrations from 2.5 mEq/L to lower levels. There has been no rigorous systematic examination of the effects of such a reduction on clinical and biochemical outcomes.

STUDY DESIGN:

Retrospective cohort study.

SETTING & PARTICIPANTS:

Medicare-eligible patients who received in-center hemodialysis at a large dialysis organization in January 2008 to December 2010.

PREDICTOR:

Facility conversion from predominant use (≥75% patients) of 2.50-mEq/L dialysate calcium to predominant use of lower dialysate calcium concentrations versus maintenance of predominant use of 2.50-mEq/L dialysate calcium.

OUTCOMES:

All-cause and cause-specific mortality and hospitalization, laboratory markers of metabolic bone disease, and drug utilization.

MEASUREMENTS:

Hierarchical mixed linear and Poisson models were fit to compare pre- to postconversion differences in outcomes between converter and matched control facilities. Results, expressed as relative rate ratios (RRRs) and delta-delta (change in mean values), were estimated for early (months 0-2) and late (months 3-12) postconversion to allow for possible latent effects.

RESULTS:

Facility conversion was associated with greater rates of hospitalization for heart failure exacerbation (late RRR, 1.27 [95% CI, 1.06-1.51]), hypocalcemia (early RRR, 1.19 [95% CI, 1.05-1.35]; late RRR, 1.39 [95% CI, 1.20-1.60]), and intradialytic hypotension (early RRR, 1.07 [95% CI, 1.02-1.11]; late RRR, 1.05 [95% CI, 1.01-1.10]), but no differences were observed for all-cause mortality or hospitalization rates. Facility conversion was also associated with comparative temporal decreases in serum calcium level, increases in serum phosphate and parathyroid hormone levels, and increases in use of phosphate binders, vitamin D, and calcimimetics.

LIMITATIONS:

Possible residual confounding, generalizability beyond Medicare patients uncertain.

CONCLUSIONS:

There are potential safety concerns associated with the default use of dialysate calcium concentrations < 2.50 mEq/L, as well as biochemical evidence of poorer disease control despite associated greater medication use. Individualization of dialysate calcium concentration rather than predominant use of dialysate calcium concentrations < 2.50 mEq/L should be considered.

• Authors: Steven M Brunelli, Scott Sibbel, Thy P Do, Kerry Cooper, Brian D Bradbury
• Journal: American journal of kidney diseases : the official journal of the National Kidney Foundation (Am J Kidney Dis) Vol. 66 Issue 4 Pg. 655-65 (Oct 2015) ISSN: 1523-6838 [Electronic] United States
• PMID: 26015274 (Publication Type: Journal Article, Observational Study, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Chemical References

• Biomarkers
• Hemodialysis Solutions
• Calcium

Topics

• Aged
• Biomarkers (blood)
• Calcium (analysis, blood)
• Cause of Death
• Cohort Studies
• Female
• Follow-Up Studies
• Heart Failure (etiology, mortality)
• Hemodialysis Solutions (adverse effects, chemistry)
• Hemodialysis Units, Hospital
• Humans
• Kidney Failure, Chronic (blood, mortality, therapy)
• Linear Models
• Male
• Medicare
• Middle Aged
• Myocardial Infarction (etiology, mortality)
• Poisson Distribution
• Prognosis
• Renal Dialysis (adverse effects, methods)
• Retrospective Studies
• Risk Assessment
• Stroke (etiology, mortality)
• Survival Analysis
• Treatment Outcome
• United States