Design

This study is a randomized, double-blind, controlled, single-center, clinical, pilot trial (Fig. 1), which was designed in accordance with the Consolidated Standards of Reporting Trials (CONSORT 2010) guidelines as well as the Standards for Reporting Interventions in Controlled Trials of Acupuncture (STRICTA) [6]. As the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) checklist shows in Additional file 1, we are selecting in-patients who have undergone laparoscopic cholecystectomy (LC) between January 2016 and June 2016 at the Department of Minimally Invasive Surgery of Tianjin Nankai Hospital. The APP will be performed by specialist nurses who have more than 5 years of experience and have held intermediate professional titles.

Flow chart of the study

Patients will be randomly assigned either to the APP group or to the APP sham stimulation group on the basis of numbers randomly generated using SPSS 19.0. A specifically appointed investigator will be responsible for the randomization. The APP (or sham stimulation) will be performed 6 h after surgery and every 12 h subsequently; six sessions will be conducted, each lasting 3 min. The first evaluation will be performed immediately before the first APP session (6 h after surgery), and then every 12 h for seven evaluations.