Randomized Crossover Trial of Blood Volume Monitoring-Guided Ultrafiltration Biofeedback to Reduce Intradialytic Hypotensive Episodes with Hemodialysis

Abstract

Background and objectives: Intradialytic hypotension (IDH) is associated with morbidity. The effect of blood volume-guided ultrafiltration biofeedback, which automatically adjusts fluid removal rate on the basis of blood volume parameters, on the reduction of IDH was tested in a randomized crossover trial.

Design, setting, participants, & measurements: We performed a 22-week, single blind, randomized crossover trial in patients receiving maintenance hemodialysis who had >30% of sessions complicated by symptomatic IDH in five centers in Calgary, Alberta, Canada. Participants underwent a 4-week run-in period to standardize dialysis prescription and dry weight on the basis of clinical examination. Those meeting inclusion criteria were randomized to best clinical practice hemodialysis (control) or best clinical practice plus blood volume-guided ultrafiltration biofeedback (intervention) for 8 weeks, followed by a 2-week washout and subsequent crossover for a second 8-week phase. The primary outcome was rate of symptomatic IDH.

Results: Thirty-five participants entered, 32 were randomized, and 26 completed the study. The rate of symptomatic IDH with biofeedback was 0.10/h (95% confidence interval, 0.06 to 0.14) and 0.07/h (95% confidence interval, 0.05 to 0.10) during control (P=0.29). There were no differences in the rate or proportion of sessions with asymptomatic IDH or symptoms alone. Results remained consistent when adjusted for randomization order and study week. There were no differences between intervention and control in the last study week in interdialytic weight gain (difference [SD], -0.02 [0.8] kg), brain natriuretic peptide (1460 [19,052] ng/L), cardiac troponins (3 [86] ng/L), extracellular water-to-intracellular water ratio (0.05 [0.33]), ultrafiltration rate (1.1 [7.0] ml/kg per hour), and dialysis recovery time (0.43 [19.25] hours).

Conclusion: The use of blood volume monitoring-guided ultrafiltration biofeedback in patients prone to IDH did not reduce the rate of symptomatic IDH events.

Keywords: Alberta; Biofeedback, Psychology; Blood Volume; Canada; Confidence Intervals; Cross-Over Studies; Fluid Therapy; Natriuretic Peptide, Brain; Random Allocation; Single-Blind Method; Troponin; Water; Weight Gain; biofeedback; hemodialysis; hypotension; intradialytic hypotension; randomized controlled trials; renal dialysis; ultrafiltration.

Figure 1.

Participant flow diagram. GI, gastrointestinal; HD, hemodialysis; IDH, intradialytic hypotension.

Figure 2.

The rate of symptomatic IDH did not differ in each period between the two randomization orders. In randomization order A, biofeedback in period 1 followed by control in period 2. In randomization order B, control in period 1 followed by biofeedback in period 2. IDH, intradialytic hypotension.

Figure 3.

Although there was a significant reduction in the rate of symptomatic IDH from run-in to the eighth week in the biofeedback period, there were no differences between the two treatments at the eighth week. IDH, intradialytic hypotension.

Figure 4.

The results of the analysis for rates of symptomatic IDH, asymptomatic IDH, and symptoms alone remained consistent with the primary analysis. Symptomatic IDH rate did not differ between the run-in and the biofeedback period (P=0.12), but decreased between the run-in and the control period (P=0.01). There was no difference between the biofeedback and the control period (P=0.29). Asymptomatic IDH rate did not differ between the run-in and the biofeedback period (P=0.77) or the run-in and the control period (P=0.83); there were no differences between the biofeedback and the control period (P=0.64). Symptoms alone rate did not differ between the run-in and the biofeedback period (P=0.20) or the run-in and the control period (P=0.64); there were no differences between the biofeedback and the control period (P=0.37). IDH, intradialytic hypotension.