An on-line monitor of dialyzer Na and K flux in hemodialysis.
A closed loop Na kinetic model is developed which permits 1) prescription of precise profiles of Na removal from its extracellular volume of distribution ((dVeCe)/dt), while 2) assuring that the total interdialytic accumulation of Na is removed during each dialysis. The model requires precise continuous measurement of Na flux in the dialysate stream, and a device to accomplish this (Ionflow) was developed and evaluated. In vivo studies showed that changes in body content of Na agreed to +/- 40 mEq, with total Na flux measured by Ionoflow. This agreement is excellent, considering that +/- 1 mEq/L in blood Na represents approximately 40 mEq in the average patient. The Ionoflow is considered accurate to +/- 10 to 20 mEq Na over a dialysis. The Ionoflow fulfills monitoring requirements necessary to implement clinical trials of closed loop Na modeling.
Gotch
F
F
Davies Medical Center, San Francisco, California.
Evans
M
M
Metzner
K
K
Westphal
D
D
Polaschegg
H
H
D015314:Dialysis Solutions / Q000032:analysis; D006801:Humans; D007688:Kidneys, Artificial; D008432:Mathematical Computing; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D009862:Online Systems / Q000295:instrumentation*; D011188:Potassium / Q000097:blood*; D012964:Sodium / Q000097:blood*
D015314:Dialysis Solutions; D012964:Sodium; D011188:Potassium