Conditions: Postoperative Nausea and Vomiting
Keywords: Postoperative nausea and vomiting Transcutaneous electrical acupoint stimulation Gynecological laparoscopic surgery Tropisetron Dexamethasone
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 157
Healthy volunteers: no

Brief summary:
The purpose of this study is to access the effect of TEAS of P6 in the prevention of PONV in women scheduled for gynecologic laparoscopic surgery with general anesthesia.

Detailed description:
150 female patients, aged between 18 to 60 y, who are scheduled for elective gynecological laparoscopic surgery requiring general anesthesia, will be randomly allocated by a computer generated randomization table to acustimulation group (Group Acu), tropisetron group (Group Trp),or dexamethasone group (Group Dxm).

In Group Acu, a surface electrode will be applied in the induction room to the P6 acupoint 30 min before induction.An operator will set electric stimulating current at 1mA with frequency at 2 Hz, and gradually increased the current intensity to a little below discomfort threshold.The stimulation will be maintained until the patient is discharged from the post-anesthesia care unit (PACU). In Group Trp and Group Dxm, the same protocol will be applied unless silicone covers attached to both electrodes.

A standardized anesthetic protocol will be followed. After induction, dexamethasone 10mg i.v. will be given in all groups. All patients will receive intravenous lactated Ringer's solution based on calculated preoperative deficits, surgical procedure, and estimated intraoperative blood loss. Parecoxib 40mg i.v. during surgery and incision infiltration of 0.5% ropivacaine at the end of surgery will be used for post-operative analgesia. After surgery, analgetic therapy will continue with morphine upon patient's request.After extubation, patients will be transported to PACU and observed for no less than 30 min. Metoclopramide 10mg i.v. will be administered as a rescue therapy to any patient who experiences an episode of moderate or severe nausea, an episode of vomiting, and requests rescue medication.

At the start of skin closure, a prefilled syringe which contains 5 ml of a solution will be administered intravenously to the patient. It will contain either saline (Group Acu and Group Dxm) or tropisetron 5mg (Group Trp).The syringe with the drug will be prepared by a study coordinator according to group allocation.

The patients, the anesthesiologists, and the nursing staff shall be unaware of the group assignments.

An anesthesiologist and an anesthetic nurse, who are trained for the study and blinded to the randomization, will collect the data.

Arms:
arm 1: Transcutaneous electrical acupoint stimulation (TEAS) starts 30 min before surgery and lasts until patient leaves the postanesthetic care unit.Dexamethasone 10mg i.v. after induction. arm 2: Tropisetron 5mg iv. at the start of skin closure.Sham transcutaneous electrical acupoint stimulation.Dexamethasone 10mg i.v.after induction. arm 3: Sham transcutaneous electrical acupoint stimulation. Dexamethasone 10mg i.v.after induction.

Interventions: intervention 1: Transcutaneous electrical acupoint stimulation intervention 2: Sham transcutaneous electrical acupoint stimulation intervention 3: Tropisetron intervention 4: Dexamethasone
Intervention descriptions: intervention 1: A surface electrode will be applied to the P6 acupoint on the dominant upper extremity, located approximately 3cm proximal to the distal wrist crease between the tendons of the flexor carpi radialis and the palmaris longus, and a negative surface electrode placed on the opposing dorsum aspect of the forearm. intervention 2: The same TEAS protocol will be applied unless silicone covers will be attached to both electrodes. The device will also be turned on during the procedure. intervention 3: will be given at the start of skin closure intervention 4: will be given after induction

Protocol document: