Opioid-free Anesthesia and Postoperative Delirium
Summary
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. This single-centre, prospective, randomized controlled trial will be conducted at the First Affiliated Hospital of Shandong First Medical University, China. A total of 654 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. 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.
Timeline
- Start
- 2026-05-01
- Primary completion
- 2028-04-30
- Completion
- 2028-06-30
Publications
- Background Kreutzmann HPMMR, Palm P, Rasmussen TB, Ahlehoff O, Helmark C, Instenes I, Larsen JKP, Lassen JF, Ryg J, Jensen LO, Norekval TM, Borregaard B; CONCARD Investigators. The association between self-reported frailty status and 1-year all-cause mortality and readmission following PCI: A prospective multi-centre cohort study, CONCARDPCI. Int J Cardiol. 2026 Mar 1;446:134072. doi: 10.1016/j.ijcard.2025.134072. Epub 2025 Dec 5.
- Background Howell SJ, Dhesi JK. Frailty in the perioperative setting: lessons from SNAP-3. Br J Anaesth. 2025 Aug;135(2):296-299. doi: 10.1016/j.bja.2025.05.024. Epub 2025 Jun 24.
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- Background Desrochers RM, Lynch LJ, Gates JD, Ricaurte D, Wade JT, Dicks RS, Keating JJ. Outcomes in Post-operative Delirium Following Bowel Resection: A Single Center Retrospective Review. J Surg Res. 2022 Dec;280:163-168. doi: 10.1016/j.jss.2022.07.009. Epub 2022 Aug 13.
- Background Li H, Liu C, Yang Y, Wu QP, Xu JM, Wang DF, Sun JJ, Mao MM, Lou JS, Liu YH, Cao JB, Duan CY, Mi WD. Effect of Intraoperative Midazolam on Postoperative Delirium in Older Surgical Patients: A Prospective, Multicenter Cohort Study. Anesthesiology. 2025 Feb 1;142(2):268-277. doi: 10.1097/ALN.0000000000005276. Epub 2024 Oct 29.
- Background Dilmen OK, Meco BC, Evered LA, Radtke FM. Postoperative neurocognitive disorders: A clinical guide. J Clin Anesth. 2024 Feb;92:111320. doi: 10.1016/j.jclinane.2023.111320. Epub 2023 Nov 8.
- Background Aldecoa C, Bettelli G, Bilotta F, Sanders RD, Aceto P, Audisio R, Cherubini A, Cunningham C, Dabrowski W, Forookhi A, Gitti N, Immonen K, Kehlet H, Koch S, Kotfis K, Latronico N, MacLullich AMJ, Mevorach L, Mueller A, Neuner B, Piva S, Radtke F, Blaser AR, Renzi S, Romagnoli S, Schubert M, Slooter AJC, Tommasino C, Vasiljewa L, Weiss B, Yuerek F, Spies CD. Update of the European Society of Anaesthesiology and Intensive Care Medicine evidence-based and consensus-based guideline on postoperative delirium in adult patients. Eur J Anaesthesiol. 2024 Feb 1;41(2):81-108. doi: 10.1097/EJA.0000000000001876. Epub 2023 Aug 30.
- Background Sim JH, Kim KM, Lee U, Lee EK, Noh GJ, Choi BM. Incidence of postoperative delirium and quality of recovery in older patients undergoing gastrectomy under general anaesthesia with remimazolam vs. propofol: a randomised non-inferiority study. Anaesthesia. 2025 Nov;80(11):1370-1380. doi: 10.1111/anae.16684. Epub 2025 Jul 14.
- Background Scholz AF, Oldroyd C, McCarthy K, Quinn TJ, Hewitt J. Systematic review and meta-analysis of risk factors for postoperative delirium among older patients undergoing gastrointestinal surgery. Br J Surg. 2016 Jan;103(2):e21-8. doi: 10.1002/bjs.10062. Epub 2015 Dec 16.
- Background Liu J, Wang T, Song J, Cao L. Effect of esketamine on postoperative analgesia and postoperative delirium in elderly patients undergoing gastrointestinal surgery. BMC Anesthesiol. 2024 Feb 1;24(1):46. doi: 10.1186/s12871-024-02424-w.
Drugs
| Evaluation | Drug | Modality | Dose | Route |
|---|---|---|---|---|
| Subject | Dexmedetomidine | Other / unclassified | 0.5 ug/kg | Intravenous |
| Subject | Dexmedetomidine | Other / unclassified | 1 ug/kg | Intravenous |
| Subject | Esketamine | Other / unclassified | 0.2 mg/kg | Intravenous |
| Subject | Esketamine | Other / unclassified | 0.5 mg/kg | Intravenous |
| Subject | Esketamine | Other / unclassified | 1.5 mg/kg | Intravenous |
| Subject | Esmolol | Other / unclassified | 20 ug/kg | — |
| Subject | Esmolol | Other / unclassified | 100 ug/kg | — |
| Subject | Remifentanil | Small molecule | 0.2 ug/kg | — |
| Subject | Remifentanil | Small molecule | 1 ug/kg | — |
| Subject | Sufentanil | Other / unclassified | 0.15 ug/kg | Intravenous |
| Subject | Sufentanil | Other / unclassified | 0.3 ug/kg | Intravenous |
| Subject | Sufentanil | Other / unclassified | 0.5 ug/kg | Intravenous |
| Subject | Sufentanil | Other / unclassified | 2 ug/kg | Intravenous |
| Background | OFA group | Unknown | 1 % | — |
| Background | Ondansetron | Other / unclassified | 8 mg | — |
| Background | Ondansetron | Other / unclassified | 16 mg | — |
| Background | Propofol | Small molecule | 2 mg/kg | Intravenous |
| Background | Propofol | Small molecule | 6 mg/kg | Intravenous |
| Background | Rocuronium | Other / unclassified | 5 ug/kg | Intravenous |
| Background | Rocuronium | Other / unclassified | 6 ug/kg | Intravenous |