title: Effect of modulated-frequency and modulated-intensity transcutaneous electrical nerve stimulation after abdominal surgery: a randomized controlled trial.
abstract: OBJECTIVE
  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.
  
  
  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.
authors.affiliation: Heisei Memorial Hospital, Kashihara City, Nara, Japan.
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Tokuda
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Tabira
authors.forename: Takashi
authors.initials: T
authors.lastname: Masuda
authors.forename: Takashi
authors.initials: T
authors.lastname: Nishiwada
authors.forename: Koji
authors.initials: K
authors.lastname: Shomoto
mesh_terms: D000005:Abdomen / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D010535:Laparoscopy / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010149:Postoperative Pain / Q000503:physiopathology / Q000628:therapy*; D011446:Prospective Studies; D016037:Single-Blind Method; D013147:Spirometry; D018709:Statistics, Nonparametric; D004561:Transcutaneous Electric Nerve Stimulation / Q000379:methods*