Abstract: TH-PO332
Dialysate Potassium (K) Concentration and Total Dialysate Volume per Week During More Frequent Hemodialysis (MFHD) Determine Serum K After Transfer from In-Center Hemodialysis (ICHD): Model Predictions
Session Information
- Dialysis: Dialysate and Clearance
October 25, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 701 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Leypoldt, J. Ken, Unaffiliated, San Clemente, California, United States
- Weinhandl, Eric D., NxStage Medical, Inc., Victoria, Minnesota, United States
- Kraus, Michael A., NxStage Medical, Inc, FISHERS, Indiana, United States
- Collins, Allan J., NxStage Medical, Inc., Victoria, Minnesota, United States
Background
Low dialysate K concentrations during ICHD induce rapid intradialytic K removal and low postdialysis serum K concentrations; low dialysate K concentrations are also associated with a higher risk of sudden cardiac arrest. Using a mathematical model, we evaluated the effect of the MFHD prescription on predialysis serum K concentration (Kpre), postdialysis serum K concentration (Kpost) and intradialytic decrease in serum K concentration (ΔKintra) after transfer from ICHD.
Methods
The mathematical model was modified from one previously published (Agar et al, Hemodial Int 2015) by accounting for colonic K clearance. MFHD prescriptions included treatment frequencies of 3.5, 4, 5 and 6 treatments per week, dialysate volumes of 20-60 L/treatment and treatment durations of 120-240 min. Predialysis serum K concentration during ICHD was assumed between 4.0 and 5.5 mEq/L with a dialysate K concentration of 2 mEq/L.
Results
Model-predicted Kpre, Kpost, and ΔKintra during MFHD were primarily dependent on total dialysate volume per week (TDV) and dialysate K concentration. A schematic weekly profile of serum K during ICHD and MFHD is illustrated in the figure. The range of TDV on MFHD with dialysate K concentrations of 1 and 2 mEq/L required to decrease Kpre, Kpost and ΔKintra below that during ICHD are tabulated.
Conclusion
We conclude that transfer from ICHD to MFHD with low TDV can result in a lower Kpre without reducing Kpost or ΔKintra for dialysate K and MFHD prescriptions typically seen in clinical practice. As with any hemodialysis therapy, additional vigilance is required for patients persistently presenting with hypokalemia or those prescribed high TDV.
| TDV required to decrease K value below that during ICHD | |||
| MFHD Dialysate K | Kpre | Kpost | ΔKintra |
| 1 mEq/L | 80-120 L | 120-200 L | >360 L |
| 2 mEq/L | 120-175 L | 300 L | >360 L |
Funding
- Commercial Support – NxStage Medical