Transcutaneous electrical nerve stimulation following appendicectomy: the placebo effect

A controlled trial was undertaken to compare the efficacy of transcutaneous electrical nerve stimulation (TENS) with standard intramuscular opiate analgesia in the management of postoperative pain following appendicectomy. Consecutive patients undergoing emergency appendicectomy were randomised into control, sham TENS and active TENS groups. There was a significant decrease in pain severity and analgesic intake in both active and sham TENS groups when compared with the control group (P less than 0.01). No difference was demonstrated in pain severity between active and sham TENS groups but the active TENS group required slightly less analgesia. These results suggest that the major benefit of TENS in the postappendicectomy patient is due to its 'placebo effect' and its use in this situation cannot be recommended.