Hemodialysis: A Sea Change Needed, Not Realized

The treatment of end-stage renal disease, ESRD, in the second decade of the 21st century involves a half-million patients in the US, for whom about $30 billion are spent each year, with fewer than 5% significantly rehabilitated.  Surprisingly, after years of exotic research, the accepted most critical problem of these patients is water management, and there is not yet a way to match water removal and water generation rates, which leads to unacceptable accumulations between thrice-weekly treatments   A thoroughly researched, 'simple' method for removing water continuously would be a superb sea change, but it doesn't yet work.  This paper will review technical approaches, problems, and prospects for therapeutic improvement in a growing patient population surrounded by a cost-contained healthcare system. In particular the promise and new problems involved in ambulatory blood processing will be enumerated and assessed in terms of those that are fundamental, like coagulation and membrane fouling versus those that should respond to known technical innovations.  All blood processing devices are nominally microfluidic but biological and artificial microfluidic systems differ in numerous important ways that will also be assessed.