Effects of Opioid-free Anaesthesia on Postoperative Delirium after Gastrointestinal Surgery in Frail Elderly Patients: A Study Protocol for A Single-centre, Prospective, Randomized Controlled Trial

Introduction: The incidence of postoperative delirium (POD) is high in frail elderly patients who have undergone gastrointestinal surgery, and POD significantly increases the risk of complications and medical burden. Opioid-free anaesthesia (OFA) involves a multimodal analgesic strategy, which may help to reduce the risk of POD. However, relevant studies focusing on frail elderly patients are still limited. This study aims to investigate the effect of OFA on the occurrence of POD in frail elderly patients after gastrointestinal surgery. Methods: This single-centre, prospective, randomized controlled trial (RCT) will be conducted at the First Affiliated Hospital of Shandong First Medical University, China. A total of 44 frail elderly patients aged 65 years or older who plan to undergo elective gastrointestinal surgery (modified frailty index (mFI > 0.27) will be randomly assigned to either the OFA group (receiving dexmedetomidine, esmolol, and ketamine) or the opioid-based anaesthesia (OBA) group. The primary outcome is the incidence of POD within 7 days after surgery or at discharge. Secondary outcome measures include the perioperative stress response, inflammation, intraoperative haemodynamics, postoperative 30-day all-cause mortality, intraoperative haemodynamic changes, 15-item quality of recovery (QoR-15), and postoperative complications during hospitalization. This study focuses on frail elderly individuals (a high-risk population) and aims to investigate the potential benefits of the OFA strategy in reducing the incidence of POD by reducing exposure to opioids through multimodal analgesia. If positive results are obtained in this study, they may provide new evidence for optimizing the perioperative management of such patients. This study is a single-centre, prospective RCT, and the results can provide preliminary evidence for subsequent studies to be performed on a larger scale. Discussion: This study focuses on frail elderly individuals (a high-risk population) and aims to investigate the potential benefits of the OFA strategy in reducing the incidence of POD by reducing exposure to opioids through multimodal analgesia. If positive results are obtained in this study, they may provide new evidence for optimizing the perioperative management of such patients. This study is a single-centre, prospective RCT, and the results can provide preliminary evidence for subsequent studies to be performed on a larger scale. Trial registration: NCT07603596.