Influence of dialysate and membrane biocompatibility on hemodynamic stability in hemodialysis.

The contributions of membrane biocompatibility, dialysate temperature and sodium concentration to hemodynamic stability during hemodialysis were studied in 8 patients with a high incidence of hemodialysis-induced symptomatic hypotension. Patients were treated during 8 different periods, randomly ordered in each case, resulting from the combination of the following: the membrane, either Cuprophan or Polyacrylonitrile; the dialysate temperature, 37 or 35 degrees C, and the sodium concentration, 133 or 139 mmol/l. The incidence of symptomatic hypotension was lower at 35 degrees C in the entire study with either membrane and either sodium concentration. It was also lower with a sodium concentration of 139 mmol/l with either temperature and either membrane. There was a lower incidence of symptomatic hypotension when using Polyacrylonitrile, but this difference was not significant. We conclude that changes in physicochemical parameters of dialysate lead to worth-while improvement of symptomatic hypotension in hemodialysis patients, but membrane biocompatibility seems to play a minor role.