About 4 million people per year in the U.S. receive intravenous contrast dye as part of an imaging or interventional procedure. Contrast-induced nephropathy (CIN) is a well-known consequence, especially for those patients with pre-existing kidney dysfunction. The traditional treatment has been various combinations of IV hydration, N-Acetylcysteine, Sodium Bicarbonate, and Lasix.
The RenalGuard system from PLC Systems, Inc. (approved in Europe in 2007) is a closed-loop fluid replacement controller. It precisely measures urine output and replaces the exact same amount of fluid intravenously. The idea is to use this continuous replacement of fluid in conjunction with a loop diuretic such as Lasix to produce high urine flow rates, which, the thinking goes, promotes more rapid transit of the potentially toxic contrast agents through the nephrons, ultimately protecting the kidney from damage.
In a recent study, the REMEDIAL II trial, the RenalGuard system (maintaining high urine flow + N-AC + low-dose Lasix) was compared to N-AC + Sodium Bicarbonate. The RenalGroup had an 11% rate of kidney injury compared to 20.5% in the other group. See the link to the full presentation for complete data.
This device represents another instance where a mostly closed-loop controller handles “routine” tasks that require frequent adjustment and leaves the physician able to focus on the more dynamic and complex parts of patient care.
Slideshow from the ACC presentation (PDF)…
Product page: RenalGuard System