• Hyponatremia can occur when sodium concentration is high and the conductivity monitors of the dialysis machine are not functioning or the alarms are not set properly
• Dialysate conductivity can be incorrectly sensed as low by the coated conductivity cells (that gets coated by granules from less soluble batch of sodium bicarbonate powder)¹
  • At the start of dialysis if an error is made when connecting concentrate containers
  • During dialysis if containers run dry and conductivity monitor fail

Treatment

• Dialysis can be resumed with dialysate sodium 2 mEq/L lower than plasma sodium concentration while infusing isotonic saline. Use of dialysate sodium 3-5 mEq/L lower than plasma sodium might increase the risk of disequilibrium syndrome.

Prevention

• Frequent check of conductivity monitors which can get coated with bicarbonate granules² and can cause falsely low readings

References:

1. Williams DJ, Jugurnauth J, Harding K, Woolfson RG, Mansell MA. Acute hypernatraemia during bicarbonate-buffered haemodialysis. Nephrol Dial Transplant 9:1170-1173, 1994
2. Sterns RH, Silver SM. Hemodialysis in hyponatremia: Is there a risk? Semin Dial 3:3-4, 1990