Purpose To explore the influence of preoperative vagus nerve block (VNB) on postoperative nausea and vomiting (PONV) in patients undergoing thoracic or abdominal laparoscopic surgery. Methods Patients were randomly divided into the VNB group (V group, n=60)  and the control group (C group, n=60). The V group received left VNB before anesthesia induction, while the C group did not receive any intervention. The incidence and severity of PONV within one day after surgery were compared between the two groups to evaluate the effect of left VNB on PONV in patients.  Results The incidence of PONV in the V group (25%) was significantly lower than that in the C group (60%) (χ2 = 15.038, P < 0.001). The incidences of mild and severe PONV in the V group were 16.67% and 8.33%, respectively, while those in the C group were 36.67% and 23.33%, respectively. The differences between the two groups were significant (mild: χ2 = 6.136, P = 0.013; severe: χ2 = 5.065, P = 0.024). Conclusion Left VNB can reduce the incidence and severity of PONV caused by thoracic or abdominal laparoscopic surgery. Trial registration Trial was prospectively registered in the Chinese Clinical Trial Registry (number: ChiCTR2100044470)

The authors have declared no competing interest.

Trial was prospectively registered in the Chinese Clinical Trial Registry (number: ChiCTR2100044470).

https://www.chictr.org.cn/searchproj.html

The author(s) received no specific funding for this work.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

On September 20, 2021, the Ethics Committee of the Affiliated Cancer Hospital of Xinjiang Medical University (Chair: Professor Xiu Hua Zhang) granted ethical approval for this study (Ethics No: K-2021053).

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

All relevant data are within the manuscript and its Supporting Information files.