Effects of dialysate to serum sodium (Na+) alignment in chronic hemodialysis (HD) patients: retrospective cohort study from a quality improvement project.

BACKGROUND: Evidence indicates favorable effects of dialysate (DNa+) to serum sodium concentration (SNa+) alignment, however, results from larger sample populations are needed. For this reason, we conducted a retrospective propensity score-matched cohort study from a quality improvement project to investigate the effects of alignment on population of maintenance hemodialysis patients. METHODS: At 4 participating hemodialysis (HD) clinics, patients with SNa+ lower than the standard DNa+ of 137 mEq/L who received HD with DNa+ aligned to the average of the last 4 SNa+ measurements were evaluated (clinicaltrials.gov # NCT01825590 ). In this retrospective data analysis, an intention-to-treat (primary) and an as-treated "intervention" (secondary) cohort were created. "Aligned" patients from both cohorts (N = 163 for the primary and N = 137 for the secondary) were then propensity-score matched in a 1:1 fashion to "unaligned" patients from the Renal Research Institute database. The propensity score was generated based on age, gender, white race, Hispanic ethnicity, absence or presence of diabetes, hemodialysis vintage, interdialytic weight gain (IDWG; as a percentage of postdialysis body weight), catheter as primary dialysis access, predialysis systolic blood pressure, serum sodium concentration, hospitalization count during baseline. T-Test was employed for group comparisons of changes to the primary (volume-related and hemodynamic parameters) and tertiary outcomes. All-cause and fluid overload-related hospitalization admission rates were compared using Wilcoxon Rank Sum test and Cox regression analysis for repeated events. RESULTS: In the primary analysis, aligned and unaligned subjects showed comparable demographics at baseline. Treatment effects were significant for IDWG [-0.12 (95% CI -0.24 to 0) L] and showed decreasing non-significant trends for pre-dialysis hemodynamic parameters. Count comparison and Cox regression analysis showed no clear advantage of alignment in terms of all-cause and fluid overload-related hospitalization. CONCLUSIONS: Results from the largest sodium alignment program to date suggest positive treatment effects on volume-related and hemodynamic parameters, but no clear effect on risk of hospitalization. Well-matched control patients minimized confounding effects. Small effects and lack of significant differences may be explained by a low baseline DNa+ limiting the interventional change.

Complications associated with the development of bacteremia with Staphylococcus aureus.

Access-related infections are a leading cause of morbidity and mortality among hemodialysis patients. Staphylococcus aureus bacteremia accounts for 25% of these episodes. Nissenson et al., found that 20.7% of the patients developing S. aureus bacteremia had infectious complications as well as hospital readmissions related to the S. aureus bacteremia. This retrospective analysis did not determine whether the S. aureus bacteremia was access related, nor how each episode was treated. We have prospectively collected a database of all access-related S. aureus bacteremia developing in our unit between 1/1/03 and 8/31/05, including the management of the access. Episodes of S. aureus bacteremia with an identifiable source other than the vascular access were excluded. Seventy-two episodes of S. aureus bacteremia were identified; 54 developed in patients using a catheter and 18 developed in patients using an arteriovenous graft/fistula. The mean age was 64+/-15 years, and 56% of the patients were Caucasian. All patients were treated with 4 weeks of antibiotics. A total of 6 (8%) deaths and 15 (20.8%) infectious complications related to the S. aureus bacteremia were identified. Infectious complications included endocarditis (4), metastatic infection (7), discitis (3), and a myocardial abscess (1). Seventeen (23.6%) of the patients were readmitted within 30 days of the episode of S. aureus bacteremia; 4 readmissions were related to the S. aureus bacteremia. Five of the 54 catheter patients who developed S. aureus bacteremia expired and 14 developed infectious complications despite the catheter being removed/exchanged in all but one patient. One of the arteriovenous graft patients who developed S. aureus bacteremia expired. We conclude that infectious complications from S. aureus bacteremia are common, as 23.6% of the patients in our study developed an infectious complication. Eight percent of the patients who developed S. aureus bacteremia expired. Strategies to avoid S. aureus bacteremia are needed.