Adjusting Fluid Removal Based on Blood Volume in Hemodialysis: A Randomized Study

As kidney function declines, the ability to maintain water balance is impaired and is most often treated with hemodialysis. The removal of excess water in hemodialysis often leads to a sudden drop of blood pressure and causes symptoms of dizziness, light-headedness, cramping, and chest pain. This sudden drop in blood pressure has been linked with complications of heart attacks, strokes and even death. Research has focused on different ways to prevent dangerous drops in blood pressure during hemodialysis. One way is the use of blood volume monitoring biofeedback technology to monitor the patient's relative blood volume and automatically reduce the amount of fluid that is being removed when the blood volume is low to prevent the drop in blood pressure from occurring. This type of biofeedback device is currently available on some hemodialysis machines and while this approach appealing, it is not clear how effective this form of biofeedback is in preventing the drops in blood pressure.

We plan to determine if the use of biofeedback based on the changes in the patient's blood volume will reduce the number of sudden drops in blood pressure that occur during hemodialysis. To do this, we will compare patients treated with this technology to current hemodialysis practices and follow them for important adverse outcomes. The result of interest will be the frequency of hemodialysis sessions complicated by a sudden symptomatic drop in blood pressure. We also plan to monitor the amount of water in the different body compartments, blood pressure, blood pressure medication use, markers of heart function, and patient symptoms and quality of life.

We hope that by providing information on this technology we can reduce the sudden drops in blood pressure in hemodialysis, the associated rates of serious disease or death, and improve patient quality of life.

This is a 22 week parallel group, randomized crossover trial to determine the effect of blood volume monitoring, BVM, guided ultrafiltration (UF) biofeedback on symptomatic intradialytic hypotension (IDH) episodes amongst IDH prone patients. The first part of the study (Part 1 - Run-In/Dialysis Optimization Phase), eligible patients will undergo a four-week run-in phase. During this period all patients will undergo a comprehensive clinical assessment including, clinical weight assessment, anti-hypertensive medication review, and dialysis prescription standardization. At the end of the run-in phase, patients that still meet eligibility criteria will enter the randomized cross-over phase. In part 2 (Randomized Cross-Over Phase), patients are randomized to regular best clinical practice hemodialysis, HD (without BVM-guided UF biofeedback; control arm) or to BVM-guided UF biofeedback (intervention arm) for an 8 week period. This will be followed by a two-week washout phase and then patients will be crossed over for a second 8-week phase. The study will be conducted and reported following the Consolidated Standards of Reporting Trials (CONSORT) 2010 guidelines.

Eligibility Criteria:
Run-in Phase Inclusion Criteria:

* \>18 years old
* Maintenance hemodialysis patients for more than 3 months
* Undergo hemodialysis 3-4 times per week for a minimum of three hours per session
* Have \>30% of their hemodialysis sessions in the preceding 8 weeks complicated by symptomatic IDH.
* Able to provide written informed consent.

Randomization Phase Inclusion Criteria:

* \>18 years old
* Maintenance hemodialysis patients for more than 3 months
* Undergo hemodialysis 3-4 times per week for a minimum of three hours per session
* Have \>30% of their hemodialysis sessions in the preceding 4 weeks complicated by symptomatic IDH.

Exclusion Criteria:

* Serum sodium ≤133mmol/L
* Hemoglobin \<80g/L
* Active Malignancy
* History of blood transfusions or hospitalizations in the preceding 4 weeks
* Planned change in the renal replacement modality during the planned study period