Individualization of Ultrafiltration in Hemodialysis
There are approximately 660,000 end-stage renal disease (ESRD) patients in the USA, with hemodialysis (HD) the primary form of treatment. High ultrafiltration rates (UFRs) are associated with intradialytic hypotension, a complication associated with adverse clinical outcomes including mortality. Individualized UFR profiles could reduce the incidence of intradialytic hypotension.
The patient's fluid dynamics during HD is described by a nonlinear model comprising intravascular and interstitial pools, whose parameters are given by the patient's estimated nominal parameter values with uncertainty ranges; the output measurement is hematocrit. We design UFR profiles that minimize the maximal UFR needed to remove a prescribed volume of fluid within a set time, with hematocrit not exceeding a specified time-varying critical profile.
We present a novel approach to designing individualized UFR profiles, and give theoretical results guaranteeing that the system remains within a pre-defined physiologically plausible region and does not exceed a specified time-invariant critical hematocrit level for all parameters in the uncertainty ranges. We test the performance of our design using a real patient data example. The designed UFR maintains the system below a time-varying critical hematocrit profile in the example.
Theoretical results and simulations show that our designed UFR profiles can remove the target amount of fluid in a given time period while keeping the hematocrit below a specified critical profile.
Individualization of UFR profiles is now feasible using current HD technology and may reduce the incidence of intradialytic hypotension.
Abohtyra R, Chait Y, Germain MJ, Hollot CV, Horowitz J. Individualization of Ultrafiltration in Hemodialysis. IEEE Trans Biomed Eng. 2018 Dec 4.