BioImpedance Spectroscopy to Maintain Renal Output: The BISTRO Trial
Research type
Research Study
Full title
BioImpedance Spectroscopy to Maintain Renal Output: The BISTRO Trial
IRAS ID
206213
Contact name
Simon Davies
Contact email
Sponsor organisation
Keele University
ISRCTN Number
ISRCTN11342007
Duration of Study in the UK
2 years, 0 months, days
Research summary
Summary of Research
Background: Most patients who develop kidney failure choose unit-based haemodialysis treatment. Dialysis removes waste products and excess fluid from the blood when the kidneys stop working properly. Haemodialysis involves diverting blood to a machine to be cleaned.One of the main functions of dialysis is to control the amount of fluid in the body. Too much fluid can lead to raised blood pressure that damages the heart and increases the risk of stroke, and may cause fluid to collect in the lungs leading to breathing difficulties. Too little fluid causes dehydration, cramps and low blood pressure and more rapid or complete loss of any remaining kidney function. Bioimpedance is a simple, bedside measurement giving information about body composition, specifically how much excess fluid is present. Clinicians can use this to guide how much fluid should be removed from the body with the normal clinical assessment of the amount of fluid in the body, but it is not known if this results in better decisions and outcomes for patients.
Research aims: To test whether taking regular measurements with a bioimpedance device, which gives information about body composition, improves outcomes for people who have newly started haemodialysis treatment for kidney failure. In particular, the study aims to see if this helps patients maintain their remaining kidney function, as this is associated with improved survival, fewer symptoms of kidney failure, fewer side effects of dialysis treatment and a better quality of life including confidence in managing their health, and cost benefit analysis.
Design and methods: People starting haemodialysis as an outpatient with some remaining kidney function will be invited to participate in a clinical trial that compares current best practice with the same but additionally guided by regular bioimpedance measurements. The study will randomise 516 patients from 30 dialysis units across the UK.
Summary of Results
Patients on hemodialysis benefit from keeping some of their own kidney function for as long as possible after starting dialysis. Removing too much fluid during dialysis, by setting a low target weight for the end of a dialysis session could accelerate its rate of loss. We wanted to see how this could be affected by developing a standardised protocol for assessing fluid status in people new to dialysis and whether device called bioimpedance, which calculates the target weight independently was better at guiding clinicians in avoiding setting target weights too low.437 people from 34 dialysis centres across the UK took part in the randomized trial for up to two years. Using bioimpedance did not result in better outcomes as clinicians were just as good in setting the target weight whether or not they used the device. We expected that about 25% would lose their own kidney function after one year. We found this was much lower in both groups, such that <25% lost their kidney function by two years. There was good evidence that clinical staff engaged with patients views when deciding whether to change the target weight. Safety, transplantation rates and numbers of deaths were not affected.
Bioimpedance does not improve on setting the target weight in the context of a standardised approach to fluid management. Applying a strategy that avoids excessive fluid removal is associated with better-than-expected preservation of kidney function.
REC name
North of Scotland Research Ethics Committee 2
REC reference
16/NS/0094
Date of REC Opinion
23 Aug 2016
REC opinion
Favourable Opinion