ESRD Renal Recovery Uptick Reported
Use of bioimpedance spectroscopy to assess volume depletion could be a factor, researchers say.
Patients with end-stage renal disease (ESRD) seldom recover renal function sufficient to stop dialysis, but new study findings suggest that this type of recovery may be on the rise.
In a poster presentation at the 2017 Annual Dialysis Conference in Long Beach, California, Elizabeth Lindley, PhD, and colleagues at the Leeds Teaching Hospital NHS Trust in the UK, reported a recent increase in the proportion of patients newly started on hemodialysis at their renal unit whose kidney function recovered enough so that they could withdraw completely from dialysis.
During the period 1980 to 2009, 1% (24/2391) of HD starters experienced sufficient kidney function recovery to discontinue dialysis compared with 4.4% (29/ 649) of patients who started HD between 2010 and October 2016. This change coincides with introduction of bioimpedance to help prevent excessive volume depletion and improved treatment of myeloma, the investigators stated.
“Changes in the treatment of myeloma have definitely been a contributing factor, but we think that the most important change in practice is that we've stopped ‘probing for dry weight' since we began using simple bedside bioimpedance spectroscopy measurements to help assess fluid status,” Dr Lindley told Renal & Urology News. “We think that being able to identify excessive fluid depletion has helped to maintain kidney function in patients starting dialysis and to give patients whose kidneys that have the potential to recover a better chance of being able to stop dialysis.”
A multicentre randomized controlled trial called BISTRO (http://www.isrctn.com/ISRCTN11342007), led by Simon Davies, MBBS, MD, Professor of Nephrology at Keele University, Stoke-on-Trent, Staffordshire, UK, has just been launched in the UK to investigate this.
Dr Lindley explained their renal unit used to systematically reduce target weight until patients were symptomatic and then back off by 0.5 kg, thinking they had found the weight that the patients would be with normal kidney function. “The bioimpedance measurements showed that patients were often asymptomatic when severely fluid depleted, and that some patients were only gaining fluid between sessions because we were taking it off.”
The median age of new HD patients increased from 50 years in the 1980's to 66 years in the 2000's, but recovery of function tended to be more likely in younger patients until the 2010's, according to the researchers.
To date, the Leeds team has been unable to explain the much higher incidence of recovery in women. Before 2010, 1 female HD patient recovered function for every 74 new starters. This ratio changed to 1 recovery for every 15 new starters after 2010. Among men, the ratio changed from 1 recovery for every 125 new starters to 1 recovery for every 32.
The median time on HD before recovery has decreased only slightly from 9 months to 7 months, but Kaplan-Meier analysis indicates that patients who recovered function since 2010 will remain off dialysis for significantly longer.
In background information on their poster, Dr Lindley's group noted that it is widely believed that residual renal function will be lost soon after initiation of HD, “so most units target a dialysis dose suitable for anuric patients and ignore renal clearance. If urine collections are carried out, it is usually to measure the volume passed, as part of setting a fluid allowance.” The researchers said they launched their study after observing a cluster of 3 HD patients who unexpectedly were able to discontinue dialysis in the summer of 2016.
1. Lindley E, Espiritu S, Hoefield R, et al. Recovery of kidney function in established hemodialysis patients: No longer the exception to the rule? Presented as a poster at the 2017 Annual Dialysis Conference in Long Beach, California.