A multicenter study of hemodialysis using individualized dialysate potassium concentrations.

Background: Dialysate potassium concentration directly affects the serum potassium level and safety of hemodialysis patients. In most dialysis centers in China, a single dialysate potassium concentration is used for dialysis, but there is no data on whether this is reasonable or not.

Methods: Serum potassium values before and after dialysis in maintenance hemodialysis (MHD) patients between 2019 and 2020 were collected from 5 hemodialysis centers in Shanghai, which uniformly use dialysate with a potassium concentration (KD) of 2.0 mmol/L, and data were collected 3 times per patient for analysis. Serum potassium fluctuation was analyzed after administration of individualized KD dialysate.

Results: In all, 1,296 MHD patients were included in the study. Predialysis serum potassium was lower than 4.5 mmol/L in 38.0% and higher than 5.5 mmol/L in 14.6% of patients. Postdialysis serum potassium was lower than 3 mmol/L in 11.3% and higher than 4 mmol/L in 10.4% of patients. Pre-dialysis serum potassium was below 4.5 mmol/L and post- dialysis serum potassium was below 3 mmol/L in 9.54% of patients. Compared with patients younger than 40 years, patients >80 years more often exhibited predialysis serum potassium below 4.5 mmol/L and Postdialysis serum potassium below 3 mmol/L. A total of 668 patients underwent a trial of hemodialysis with individualized KD dialysate. When receiving individualized KD, compared with uniform KD 2.0 mmol/L, the number of patients with postdialysis serum potassium less than 3 mmol/L significantly decreased, the following predialysis serum potassium level was not significantly different from baseline, and the proportion of patients with predialysis serum potassium less than 4.5 mmol/L and postdialysis serum potassium less than 3 mmol/L significantly decreased.

Conclusions: Hypokalemia and fluctuations of serum potassium are common in MHD patients. KD 2.0 mmol/L dialysate should not be used for all patients, and individualized KD dialysate for patients with low serum potassium reduces the incidence of hypokalemia.