Hemodialyzability of ionizable fluoride in hemodialysis session

The fluoride ion content in serum and in dialysate medium was determined by means of a fluoride ion-selective electrode in 29 patients undergoing hemodialysis treatment. Abnormally high serum fluoride of 65.9 +/- 28.3 microg l(-1) at the beginning and 46.5 +/- 26.7 microg l(-1) at the completion of the hemodialysis session was observed. Results showed that 60.0 +/- 23.9% of the serum fluoride at the beginning of the session was theoretically filterable, and 80.8 +/- 42.4% of this fraction was actually filtered throughout the hemodialysis session. The dialysis procedure is considered to be safe and adequate for serum fluoride removal. The high serum fluoride at the completion of the hemodialysis session was thought to originate from the fraction of unfilterable binding fluoride. To make further progress towards improvements in serum fluoride removal during HD, attention to the binding fraction of serum fluoride is required.