P6 stimulation for the prevention of nausea and vomiting associated with cesarean delivery under neuraxial anesthesia: A systematic review of randomized controlled trials

BACKGROUND: A number of studies investigated the use of P6 stimulation for the prevention of intraoperative and postoperative nausea and vomiting (IONV and PONV) in women having cesarean delivery under neuraxial anesthesia. We performed a systematic review to determine the overall efficacy of these techniques in preventing IONV and PONV in this patient population. METHODS: We performed a literature search of all randomized controlled trials (1966-2007) that compared different methods of P6 stimulation with placebo in women having cesarean delivery under neuraxial anesthesia. Data were extracted on the primary outcomes including the incidence of nausea, vomiting, and the need for rescue antiemetic therapy, both intraoperatively and postoperatively. RESULTS: Six Studies involving 649 patients were included in this review. Five Studies reported on intraoperative outcomes. Of these, two studies reported a significant reduction in the incidence of intraoperative nausea with P6 stimulation, and one study reported a significant reduction in rescue antiemetic requirement. However, none of the studies reported any differences between the treatment and control groups with respect to vomiting. Four studies reported postoperative outcomes. Of these, one study reported a significant reduction in postoperative nausea, two studies reported a significant reduction in postoperative vomiting, and one study reported a significant reduction in the need for postoperative rescue antiemetic therapy. CONCLUSIONS: While some Studies showed a benefit of P6 stimulation, this finding was not consistent. The presence of heterogeneity and inconsistent results among the included trials prevents any definitive conclusions on the efficacy of P6 stimulation in reducing IONV and PONV associated with cesarean delivery performed under neuraxial anesthesia.