Chinese herbal medicine as adjuvant treatment for postoperative nausea and vomiting in patients undergoing laparoscopic surgery: a protocol for systematic review and meta-analysis

IntroductionPostoperative nausea and vomiting (PONV) is a distressing symptom that patients often complain of even after less invasive surgery such as laparoscopic surgery (LS). If PONV is not well managed, patient recovery and postoperative quality of life are adversely affected. Although various drugs have been administered to prevent PONV, their effectiveness is limited, and adverse effects are numerous. Although herbal medicines have been widely used to manage various gastrointestinal symptoms, including nausea and vomiting, scientific evidence of their effects is lacking. This protocol is intended for a systematic review to analyse the efficacy and safety of Chinese herbal medicines for PONV after LS through a meta-analysis. Methods and analysisRandomised controlled trials, reported until June 2022, will be retrieved from electronic databases such as Medline, EMBASE and Cochrane Library. We will compare the effects of herbal medicine in patients presenting with PONV after LS with those of Western medicine, placebo and no treatment. If sufficient studies are identified, we will evaluate the combined effects of herbal and Western medicine. The incidence of nausea and vomiting will be considered the primary outcome. Secondary outcomes will include the intensity of complaints, quality of life and incidence of adverse events. Two independent reviewers will collect data based on the Preferred Reporting Items for Systematic Review and Meta-Analyses statement, evaluate the quality of each study using the Cochrane risk-of-bias tool and synthesise the results via meta-analysis, if possible. Ethics and disseminationEthical approval is not required for this review. The results of this study will be disseminated to peer-reviewed journals and posters. PROSPERO registration numberCRD42022345749.