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Kidney Week

Abstract: PO1052

Electrolyte Changes in Contemporary Hemodialysis: An Analysis of the Monitoring in Dialysis (MiD) Study

Session Information

Category: Dialysis

  • 701 Dialysis: Hemodialysis and Frequent Dialysis


  • Correa, Simon, Brigham and Women's Hospital, Boston, Massachusetts, United States
  • Scovner, Katherine Mikovna, Brigham and Women's Hospital, Boston, Massachusetts, United States
  • Tumlin, James A., NephroNet Clinical Research Consortium, Atlanta, Georgia, United States
  • Roy-Chaudhury, Prabir, UNC Kidney Center, Chapel Hill, NC and WG (Bill) Hefner VA Medical Center, Salisbury, North Carolina, United States
  • McCausland, Finnian R., Brigham and Women's Hospital, Boston, Massachusetts, United States
  • Charytan, David M., New York University School of Medicine and NYU Langone Medical Center, New York, New York, United States

Group or Team Name

  • Monitoring in Dialysis Study Group

There is a paucity of data examining electrolyte concentrations during and immediately after hemodialysis (HD) sessions. We describe these changes and provide predictive nomograms based on HD prescriptions and pre-HD electrolytes.


We leveraged patient (n=66) and HD session-level pre- and post-HD laboratory data (n=1,713) from the Monitoring in Dialysis study and fit mixed effects regression models to analyze differences between pre-, 15-minutes post-, and 30-minutes post-HD levels (compared with immediately post-HD) of electrolytes, blood urea nitrogen, creatinine, and albumin as well as the association of post-HD values with dialysate prescriptions.


Serum bicarbonate, calcium, and albumin increased (mean increase 4.9mEq/L±0.3, 0.7mEq/L±0.1, and 0.4g/dL±0.03, respectively), and potassium, magnesium, and phosphorus decreased immediately post-HD (mean -1.2mEq/L±0.1, -0.3mEq/L±0.03, and -3.0mg/dL±0.2, respectively). Hypokalemia and hypophosphatemia were present in 34% and 67% of immediately post-HD samples, respectively. Changes were observed in electrolyte concentrations at 15- and 30-minutes post-HD compared to immediately post-HD (Fig. A: observed changes; Fig. B: predictive nomograms of post-HD electrolytes).


Contemporary HD results in marked changes in electrolyte concentrations during and after the treatment. We report a high frequency of post-HD hypokalemia and hypophosphatemia and present predictive nomograms relating post-HD changes to dialysate prescriptions. Whether the abnormalities observed in potassium and phosphorus post-HD predispose to adverse symptoms and arrhythmia is unclear and requires further research.