Association between post-dialysis hemoglobin level and the survival of vascular access.

INTRODUCTION

Although a few dialysis facilities conduct a complete blood cell count for some patients at post-dialysis, including hemoglobin, clinical findings supporting the interpretation of results are scarce. The aim of this study was to investigate the association between post-dialysis hemoglobin level and vascular access failure with clinical data.

METHODS

Study design: Case crossover design.

SETTING

Japanese dialysis facilities, which routinely take post-dialysis blood samples, including complete blood cell counts at least once a month.

PARTICIPANTS

Hemodialysis patients who experienced vascular access failure in January 2010 until December 2014.

EXPOSURE

Post-dialysis hemoglobin level.

MAIN OUTCOME

Vascular access failure treated with endovascular treatment or operation.

STATISTICAL ANALYSIS

Self-matched odds ratios and 95% confidence intervals were estimated by comparing post-dialysis hemoglobin just before events ("case") with levels at 6 and 12 months before events ("control") using conditional logistic regression, and presented with restricted cubic spline.

RESULTS

Two hundred and thirty hemodialysis patients with vascular access failure were identified. Mean post-dialysis hemoglobin level before the failure was 11.8 g/dL (standard deviation 1.7). The spline curve showed that higher post-dialysis hemoglobin levels above 11.8 g/dL had a greater odds ratio for vascular access failure. Post-dialysis hemoglobin levels and odds ratios (95% confidence interval) for vascular access failure relative to the reference value (Hb 11.8 g/dL) were Hb 12.0 g/dL, 1.1 (1.0-1.1); Hb 14.0 g/dL, 1.4 (1.0-2.0); and Hb 16.0 g/dL, 2.1 (1.1-4.3).

CONCLUSIONS

A higher post-dialysis hemoglobin level was associated with vascular access failure. Higher post-dialysis Hb could be a factor that triggers vascular access failure.