Effect of modulated-frequency and modulated-intensity transcutaneous electrical nerve stimulation after abdominal surgery: a randomized controlled trial

Clin J Pain. 2014 Jul;30(7):565-70. doi: 10.1097/AJP.0b013e31829ea151.


Purpose: This study aimed to evaluate the effectiveness of transcutaneous electrical nerve stimulation (TENS) for treatment of postoperative pain and pulmonary functions (vital capacity [VC]; cough peak flow, [CPF]) in patients who underwent abdominal surgery.

Materials and methods: Forty-eight patients were randomly allocated to receive TENS, placebo TENS, or no TENS (control) 1 hour a day for 3 days postoperatively. A 0-100 visual analog scale was used to assess pain at preintervention, mid-intervention, and postintervention on the third postoperative day. Pulmonary functions (VC, CPF) were evaluated by spirometer at preoperation (baseline) and at preintervention, mid-intervention, and postintervention on the third postoperative day. One-way analysis of variance was used to assess differences between groups at baseline. Mann-Whitney test was used to compare the control group with the placebo-TENS and TENS group, at each assessment timepoint. Two-way analysis of variance and Bonferroni post hoc test assessed the difference between the 2 (placebo-TENS×TENS) groups. A value of P<0.01 was considered statistically significant.

Results: The baselines were not significantly different between any groups. The TENS group had significant reductions in postoperative pain compared with the placebo group (P<0.01) and control group (P<0.01). There was also improvement in pulmonary functions (VC, CPF) at mid-TENS and post-TENS, but not in the placebo-TENS (P<0.01) or control groups (P<0.01).

Conclusions: TENS is a valuable treatment to alleviate postoperative pain and improve pulmonary functions (ie, VC, CPF) in patients following abdominal surgery.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Abdomen / surgery
  • Adult
  • Aged
  • Aged, 80 and over
  • Analysis of Variance
  • Female
  • Follow-Up Studies
  • Humans
  • Laparoscopy / adverse effects*
  • Male
  • Middle Aged
  • Pain Measurement
  • Pain, Postoperative / physiopathology
  • Pain, Postoperative / therapy*
  • Prospective Studies
  • Single-Blind Method
  • Spirometry
  • Statistics, Nonparametric
  • Transcutaneous Electric Nerve Stimulation / methods*