Recovery Times in Hemodiafiltration and High-Flux Hemodialysis

Both duration and quality of life are adversely affected by the presence of end-stage renal disease (ESRD); worldwide, approximately 1.9 million people receive renal replacement therapy. Intermittent renal replacement therapy is essential for many patients with ESRD. In the developed world, extracorporeal treatments for ESRD such as hemodialysis and hemodiafiltration are more prevalent than peritoneal dialysis.

While observational data have suggested that hemodiafiltration is beneficial, data from randomized controlled trials that compared hemodiafiltration with hemodialysis have shown mixed results. Post hoc analyses have indicated that hemodiafiltration has superior cardiovascular and mortality outcomes limited to patients receiving the highest convection volumes. However, high convection volumes may not be possible in patients with suboptimal vascular access and/or time constraints associated with dialysis provision.

The length of recovery time after dialysis is an important outcome measure affecting health-related quality of life reported by patients.

Further, data from DOPPS (Dialysis Outcomes and Practice Patterns Study) have shown an association between longer postdialysis recovery time and increased mortality. James R. Smith, MBChB, and colleagues in Scotland performed a patient-blinded randomized crossover study of patient-reported recovery time to determine whether recovery time differs between hemodialysis and hemodiafiltration. The researchers reported results in the American Journal of Kidney Diseases [2017;69(6):762-770].

The outcomes of interest were post-treatment recovery time, symptomatic hypotension events, dialysis circuit clotting events, and biochemical parameters. Measurements included patient-reported recovery time in minutes, incidence of adverse events during treatments, hematology and biochemistry results, and responses to a quality-of-life questionnaire. The study intervention was 8 weeks of hemodialysis followed by 8 weeks of online postdilution hemodiafiltration or vice versa.

The total study cohort included 100 patients who were randomly assigned to receive hemodialysis and then hemodiafiltration or hemodiafiltration and then hemodialysis. Mean age was 65 years, 39% were women, and 99% were white.

Treatment time and blood flow rate remained constant between hemodialysis and hemodiafiltration. Ultrafiltration volumes were similar and the mean convection volume for hemodiafiltration treatments was 20.6 L. While participants were receiving hemodiafiltration, pretreatment systolic blood pressure was lower (143 vs 145 mm Hg; P=.03); however, the difference was not seen post treatment.

For 92% of all sessions, data on recovery time were available. Of the available data, recovery time for one-third of the sessions was reported as zero minutes (immediate), resulting in a bimodal distribution. To account for this, separate models were used to analyze immediate and delayed (>0 minutes) recovery times, then joined to obtain an overall P value. This demonstrated no overall difference in recovery time between hemodiafiltration and hemodialysis (median values of 47.5 minutes and 30 minutes, respectively; P=.9). However, individual models for immediate and delayed recovery time showed that patients were more likely to report immediate recovery while receiving hemodiafiltration treatment. Delayed recovery times were longer with hemodiafiltration compared with hemodialysis: median of 150 minutes versus 137 minutes; P<.001.

There was an association between hemodiafiltration and an increased rate of symptomatic hypotension compared with hemodialysis (8.0% vs 5.3%; relative risk [RR], 15.2; 95% confidence interval [CI], 1.2-1.9; P<.001). While on hemodialysis, three patients had increased dosing in antihypertensive medications, as did one patient on hemodiafiltration. Dosing was reduced in three patients while on hemodialysis and in one patient while on hemodiafiltration therapy.

The intradialytic tendency to clotting was higher during hemodiafiltration than during hemodialysis: 1.8% versus 0.7%; RR, 2.7; 95% CI, 1.5-5.0; P=.002.

There were no significant differences between the two treatments in the prespecified laboratory measurements. There were small but statistically significant differences in serum albumin (3.2 vs 3.3 g/dL for hemodiafiltration and hemodialysis, respectively; P<.001) and chloride levels (101 vs 100 mEq/L for hemodiafiltration and hemodialysis, respectively; P=.02).

To measure quality of life, patients completed Kidney Disease Quality of Life—Short Form, version 1.3, questionnaires during the study. At baseline, the patients scored physical health lower than mental health. After 8 weeks of each treatment, there was no difference in physical health composite scores or mental health scores.

Study limitations cited by the authors included the single-center design of the study, as well as the predominance of patients with European ancestry. Further, it is possible that the nursing staff’s longer term experience with hemodialysis compared with hemodiafiltration may have had an influence on the results.

In conclusion, the researchers said, “Debate remains regarding the clinical case for hemodiafiltration over hemodialysis. Patient preference and shared decision making are increasingly prioritized in clinical practice, and these data may further inform the discussion around choice of extracorporeal treatments.”

Takeaway Points

  1. There is no clear consensus regarding the choice between hemodiafiltration or high-flux hemodialysis in the treatment of end-stage renal disease.
  2. Researchers conducted a randomized patient-blinded crossover trial of patient-reported recovery time to determine whether recovery time differs between the two treatment options.
  3. Results demonstrated that post-treatment recovery times were similar for the two modalities; in addition, health-related quality-of-life scores were similar as well.