RESUMO
The main goal of this work was to evaluate the efficacy of transcutaneous electrical nerve stimulation (n = 25), comparatively with the effects induced by the intravenous administration of 1 g of Dipyrone (n = 25), to reduce postoperative pain during the immediate period (4 hours) following cesarean section. We undertook a clinical study in order to analyze the following variables: pain intensity, duration of pain, and additional consumption of analgesic drugs. Our data showed that both treatments resulted insufficient in order to eliminate completely postoperative pain, requiring the administration of additional analgesic drugs. This study supports previous findings reporting that transcutaneous electrical nerve stimulation induces a decrement of 50% on the total amount of analgesic drugs employed. Transcutaneous electrical nerve stimulation showed to effectively reduce the intensity and duration of pain of cutaneous origin, as well as to reduce pain associated with voluntary movements, in all patients. Perhaps due to the blocking of A peripheral fibers (somatic pain). However, in 13 patients, this treatment was insufficient to block visceral pain conducted by type C peripheral fibers. These actions may be related to the position of the stimulus electrodes, as well as to the frequency of stimulation used in our study. Taken together, our results are indicative that transcutaneous electrical nerve stimulation constitutes an alternative treatment in order to reduce postoperative pain during the immediate period following cesarean birth; reduces the requirements of analgesic drugs; helps on keeping alert the mothers and therefore able to attend the newborn; and avoids secondary effects of analgesic drugs over mother-newborn relationship. Nevertheless, it is necessary to further explore transcutaneous electrical nerve stimulation, changing the position of the stimulus electrodes, and the frequency of stimulation, in order to evaluate its effects on visceral pain.