Response of salivary flow rate to transcutaneous electrical nerve stimulation in haemodialysis patients

Introduction
Hyposalivation is one of the common oral complications in end-stage renal disease. This study aimed to assess the immediate and 3-week effects of transcutaneous electrical nerve stimulation (TENS) on hyposalivation in end-stage renal disease patients on maintenance haemodialysis.

Methods
Overall, 80 haemodialysis patients with hyposalivation complaints (40 diabetics and 40 nondiabetics with a mean age of 59.35 ± 9.59 and 59.45 ± 9.66 years, respectively) were treated with 20-minute extraoral TENS (50 Hz and 250 µs pulse duration) applied bilaterally to parotid glands for 3 successive weeks (3 sessions per week). Besides the baseline measurement, the whole resting saliva was collected immediately after the first and last TENS sessions in a graduated test tube via the 5-minute low forced spitting method. The whole resting salivary flow rate (WRSFR) (ml/min) was calculated by dividing the collected salivary volume by the 5-minute collection period.

Results
When the baseline WRSFR mean was compared with its value after the first or last TENS session, WRSFR showed a highly significant increase in diabetic and nondiabetic haemodialysis patients.

Conclusions
Extraoral electrostimulation via TENS is an effective therapeutic modality for hyposalivation in end-stage renal disease patients on maintenance haemodialysis.