Positive suggestions via headphones during general anesthesia for the improvement of vegetative & cognitive postoperative course parameters in elderly orthopedic patients – A randomized controlled double-blinded trial (POSSUDEL)

Background Postoperative delirium and cognitive deficits are significant surgical complications, especially in elderly patients. The reported incidence of postoperative delirium is variable but notably high in cardiothoracic, orthopedic, and general surgery. The etiology of postoperative delirium is known to be multifactorial, with prevention being the most effective strategy currently available. This study aims to explore the potential benefits of positive suggestions delivered via headphones during general anesthesia on the incidence of postoperative delirium and improving postoperative pain, nausea, and cognitive outcomes in elderly orthopedic patients. Methods This randomized controlled double-blinded trial will involve patients aged 60 and above undergoing elective hip or knee surgery under general anesthesia. Participants will be randomized into three groups: a control group receiving no auditory intervention and two intervention groups receiving positive therapeutic suggestions via headphones from either a male or female speaker. The primary outcome is the incidence of postoperative delirium within five days after surgery, that will be assessed by using the 4AT and 3DCAM. Secondary outcomes include pain intensity, medication consumption, postoperative nausea and vomiting, and levels of specific biomarkers. Data will be collected before, during and after surgery as well as three months after surgery. In addition, intraoperative pain is being measured objectively by using the nociception level index (NOL). Discussion This study hypothesizes that positive auditory suggestions can reduce postoperative delirium incidence, lower pain intensity as well as pain medication use, and decrease postoperative nausea, vomiting incidence and severity. Additionally, gender differences in response to male versus female voices will be explored. The findings could offer a non-invasive, cost-effective method to enhance postoperative recovery in elderly patients, potentially leading to changes in perioperative care practices. Trial registration DRKS00030589 prospectively registered 25.10.2022