Magnetic acupressure for management of postoperative nausea and vomiting: a preliminary study

To assess the efficacy of magnetic acupressure in the prevention of postoperative nausea and vomiting (PONV).

Fifty-eight patients were included in this randomized, double blind, preliminary prospective study. Thirty-three underwent ear, nose, and throat (ENT) procedures and twenty-five underwent gynaecological procedures. A magnet patch (M) or a placebo patch (P) was applied to patients in each group randomly. The patch was applied 15 min before surgery to P6 a point situated above the wrist, on the medial aspect of the arm between the palmaris longus and flexor carpi radicis (REF point). Anaesthesia was standardized for all patients. Primary study endpoints included PONV scores and number of rescue antiemetic administrations. Secondary endpoints included pain scores, percentage of patients who required rescue analgesics and satisfaction scores. Study variables were measured on arrival in the PACU and 8, 16 and 24 h after surgery.

The global incidence of PONV was 50%. We found no significant difference in the incidence of PONV between ENT patients (46%) and gynaecology patients (56%), and no difference between patients who received magnet treatment (47%) and those that did not (54%). Patients receiving the magnet had a similar satisfaction level (75% satisfied) to those receiving placebo (73% satisfied). In addition, magnet-treated patients had similar pain and PONV scores, and a similar percentage of patients in each groups received postoperative rescue analgesics. Finally, there was no difference in the number of rescue antiemetic administrations between the two groups.

The use of magnetic acupressure as a prophylactic antiemetic treatment prior to ENT or gynaecology surgeries produced no benefit when compared to placebo.