This protocol describes a single-center, prospective, randomized controlled clinical trial designed to investigate the efficacy and feasibility of transauricular vagus nerve stimulation (taVNS) in improving perioperative sleep disorders in elderly patients receiving general anesthesia.
Perioperative sleep disorders (PSDs) in elderly patients under general anesthesia are associated with high morbidity and severely affect patients' prognosis.
Vagus nerve electrical stimulation (VNS) has been shown to treat diseases related to autonomic dysfunction, and its anti-inflammatory and other mechanisms may present potential therapeutic possibilities for sleep disorders.
The trial is designed as a single-center, prospective, randomized controlled study enrolling 164 elderly patients receiving general anesthesia, randomized 1:1 to taVNS or sham stimulation.
The primary outcome is the incidence of perioperative sleep disorders within 3 days postoperatively, defined using validated scoring tools.
Secondary effectiveness and safety outcomes include multiple postoperative assessments spanning pain, anxiety, depression, delirium, and adverse events.
This paper describes the protocol (research plan) for a clinical trial that has not yet reported results. The trial, called VNstep, is testing whether a non-invasive form of nerve stimulation called transauricular vagus nerve stimulation (taVNS) — delivered through the ear — can help elderly patients sleep better after surgery under general anesthesia. Sleep problems after surgery are common in older adults and can lead to serious complications, so finding safe and effective treatments is an important clinical goal. The researchers plan to enroll 164 elderly surgical patients and randomly assign half to receive real taVNS and half to receive a sham (fake) version during the perioperative period, then track their sleep and other outcomes for several days after surgery. This research suggests that taVNS may be a promising approach because vagus nerve stimulation has shown benefits in conditions involving the autonomic nervous system and inflammation — both of which are thought to play a role in postoperative sleep disturbances. The trial will measure not only whether patients develop sleep disorders in the first three days after surgery, but also their pain levels, anxiety, depression, and whether they develop delirium (a state of confusion common in elderly surgical patients). Safety monitoring for adverse events is also built into the protocol. Because this is a protocol paper, no results are yet available — the findings reported here are the study design and rationale, not outcomes. This research matters because it represents a rigorous attempt to evaluate a low-risk, non-drug intervention for a very common and consequential problem in older surgical patients. If the trial shows that taVNS reduces postoperative sleep disorders, it could offer a new tool for improving recovery and reducing complications in elderly people undergoing surgery.
Wang T, Wu Y, Hou X, Liang F, Jian M, Yu Y, et al.. (2026). Transauricular vagus nerve electrical stimulation improves postoperative sleep disorders in elderly patients (VNstep): protocol for a randomized controlled clinical trial.. Trials. https://doi.org/10.1186/s13063-026-09459-z