METHODS	Twelve stable , non-diabetic HD patients were investigated during three one-week standardized HD periods ( 1.8 m ( 2 ) high-flux polysulphone dialyser , treatment time 240 min , Qb = 300 ml/min , Qd = 500 ml/min , dialysate without glucose , bicarbonate 40 mmol/l ) , using dialysates containing 0 ( 0K ) , 1 ( 1K ) , and 2 ( 2K ) mmol/l of K. Mass removal of K ( M ( K ) ) and u ( M ( U ) ) were measured during the mid-week treatment by partial dialysate collection .\