Analgesic effect of transcutaneous electrical nerve stimulation after laparoscopic cholecystectomy.

Abstract This study aimed to assess the effect of Transcutaneous Electrical Nerve Stimulation (TENS) on pain, nausea, and emesis in patients submitted to surgery for laparoscopic cholecystectomy. A clinical single-masked randomized study assessed patients submitted to laparoscopic cholecystectomy, who were divided into two groups: placebo TENS (G1) and active TENS (G2). The intensity of pain was determined using the visual analog scale and the 11-point Verbal Numerical Scale, applied to the participants before (M1) and 30 mins after (M2) TENS. A conventional biphasic square pulse TENS current was used, at a frequency of 150 Hz and a pulse width of 75 μsecs. The relative risks of the occurrence of nausea and emesis were calculated for groups G1 and G2. Determination of the effect of TENS on analgesia used the Mann-Whitney U test, at a significance level of 5%, to compare independent samples (Dif G1 and Dif G2). The relative risk of nausea and/or emesis was 2.17 times greater for patients from the placebo group. Pain evaluation using the visual analog scale showed median differences between M1 and M2 of 0.4 and 2.4 for groups G1 and G2, respectively. The values obtained using Verbal Numerical Scale were 0.7 (G1) and 3.0 (G2). The active TENS significantly reduced postoperative pain compared with the placebo (P