Opioid Free Anaesthesia

Background: Various analgesic modalities are adopted for perioperative analgesia in breast cancer surgeries. Opioid-free and opioid-sparing techniques are gaining popularity due to the lack of opioid-dependent undesirable effects, including respiratory depression, urinary retention, nausea and vomiting, constipation, itching, opioid-induced hyperalgesia, tolerance, addiction, and immune system disorders. The goal of this prospective randomized clinical trial is to investigate the impact of opioid-free anaesthesia (OFA) versus conventional general anaesthesia (CGA) on postoperative analgesic requirements after breast cancer surgery (lumpectomy/mastectomy, with or without axillary lymph node excision). Secondary objectives include comparative perioperative evaluation of cognitive function and postoperative adverse events during the first 48 hours atfter surgery. Comparative evaluation of intraoperative haemodynamics and hospital length of stay are also secondary objectives, as well as the incidence of neuropathic pain assessed by validated questionnaires at 3 and 6 months postoperatively. During the preoperative screening, body measurements, age, gender, ASA (American Society of Anesthesiologists) physical status classification, educational level (using a 6-level scale: elementary, middle school, high school, higher education, higher education, and postgraduate/doctoral degree), home medication, and comorbidities (using the Charlson Comorbidity Index) are recorded. Intraoperatively, the duration of anaesthesia, duration of surgery, associated intraoperative data (e.g., haemodynamic instability, adverse effects associated with protocol-administered pharmaceutical agents, etc.), and medications administered (type and quantity) are recorded. The investigators expect to recruit at least 100 participants per group.

Background Postoperative delirium (POD) is a common acute and transient form of brain dysfunction in elderly patients following surgery that can lead to serious adverse clinical outcomes and even death. Although existing studies have preliminarily investigated the effects of opioid-free anaesthesia (OFA) on POD, high-quality evidence on these effects for elderly patients undergoing gastrointestinal surgery remains limited. This study aims to investigate the effects of OFA on the development of POD in elderly patients following gastrointestinal surgery. Methods and analysis: This single-centre, prospective, randomized controlled trial will be conducted at the First Affiliated Hospital of Shandong First Medical University, China. A total of 406 patients aged 65 years or older who are scheduled for elective gastrointestinal surgery will be randomly allocated to receive either opioid-free anaesthesia (OFA; dexmedetomidine, esmolol, and esketamine) or conventional opioid-based anaesthesia (OBA). The primary outcome is the incidence of POD 7 days after surgery. The secondary outcomes are all-cause mortality within 30 days after surgery, intraoperative haemodynamic changes, the 15-item quality of recovery (QoR-15) scores at 24 h, 48 h, and 72 h after surgery, complications during postoperative hospitalization, pain numerical rating scale (NRS) score at 72 h after surgery, incidence of nausea and vomiting at 72 h after surgery, morphine milligram equivalent for analgesics at 72 h after surgery, duration of anaesthesia (from induction to discontinuation), duration of surgery (from skin incision to the last suture), duration of post-anaesthesia care unit (PACU) stay, and length of hospital stay. Discussion: The results of this study may shed light on the effects of OFA on POD in elderly patients undergoing gastrointestinal surgery. The study is designed on the basis of the following key hypothesis: the use of opioid drugs for anaesthesia may increase the risk of POD through mechanisms such as blood-brain barrier destruction, neuroinflammatory responses, and central nervous system depression. Through the single-centre and prospective design of this randomized controlled trial, this study will directly analyse differences in the effects of OFA and conventional OBA on the incidence of POD, haemodynamic stability and long-term cognitive function in elderly patients. gastrointestinal surgery.