Stimulation of the P6 Acupuncture Point for Prophylaxis of Nausea and Vomiting in Pregnant Women Submitted to Cesarean Section: A Blinded Clinical Trial

In pregnant women subjected to spinal anesthesia for a Cesarean section, episodes of nausea and vomiting are common both during and following surgery. Acupuncture for the prophylaxis and treatment of these complications has been gaining in popularity due to its low cost, simplicity, absence of side effects and confirmed efficacy. This study investigated the efficacy of stimulating the P6 acupoint in conjunction with the use of dexamethasone as prophylaxis for nausea and vomiting in pregnant women submitted to spinal anesthesia for a Cesarean section. The patients (n = 100) were randomly distributed into two groups. In the first group (n = 50), a site located one centimeter laterally from P6 was stimulated. This is not a true acupuncture point (sham acupuncture). In the second group (n = 50), P6 was stimulated. In both groups, 4 mg of dexamethasone were administered intravenously. A questionnaire was used to obtain information on the occurrence of nausea and vomiting during surgery and in the first 12 hours postpartum. The chi-square test and Fisher’s exact test were used to assess differences between the groups. Age and physical status were similar in both groups. The incidence of nausea during surgery was 32% (n = 16) in the control group and 22% (n = 11) in the P6 group (p > 0.05). In the first 12 hours following surgery, nausea occurred in 16% of the women in the control group (n = 6) and in 4% in the P6 group (n = 4) (p = 0.045). The incidence of vomiting in the control group was 12% (n = 6) during surgery and 10% (n = 5) in the postoperative period compared to 8% (n = 4) and 4% (n = 2), respectively, in the P6 group (p > 0.05). Although these differences were not statistically significant with the exception of the incidence of nausea in the first 12 hours postpartum, a reduction occurred in the incidence of all the outcomes evaluated in the P6 group.