An Early Phase 1 interventional study of S-ketamine and Dexmedetomidine in Postoperative Delirium and Elderly Patients, sponsored by Affiliated Cancer Hospital & Institute of Guangzhou Medical University. Completed at 1 site in China. Open to participants aged 60 Years to 90 Years. Per ClinicalTrials.gov, last updated 2026-05-01.
Sponsored by Affiliated Cancer Hospital & Institute of Guangzhou Medical University · Early Phase 1, Interventional, and Prevention
Postoperative delirium (POD) is a common and distressing complication after thoracic surgery. S-ketamine has neuroprotective properties as a dissociative anesthetic. Emerging literature has indicated that S-ketamine can reduce cognitive impairment in depressed patients. However, the role of S-ketamine in preventing postoperative delirium is still unknown. Therefore, this study aims to evaluate the effect of intraoperatively prophylactic S-ketamine compared to dexmedetomidine on the incidence of postoperative delirium in elderly patients undergoing non-cardiac thoracic surgery.
Postoperative delirium (POD) is a common and distressing complication after thoracic surgery. S-ketamine has neuroprotective properties as a dissociative anesthetic. Emerging literature has indicated that S-ketamine can reduce cognitive impairment in depressed patients. However, the role of S-ketamine in preventing postoperative delirium is still unknown. Therefore, this study aims to evaluate the effect of intraoperatively prophylactic S-ketamine compared to dexmedetomidine on the incidence of postoperative delirium in elderly patients undergoing non-cardiac thoracic surgery. This will be a randomized, double-blinded, placebo-and positive-controlled, non-inferiority trial that enrolls patients aged 60 or over undergoing thoracic surgery. The primary outcome will be the incidence of postoperative delirium within 4 days after surgery and assessed using a 3-minute Diagnostic Confusion Assessment Method (3D-CAM) twice a day. Secondary outcomes included postoperative delirium severity, motroic subtypes, episodes, and duration. Additional prespecified outcomes were emergence delirium; time to delirium onset; time to extubation; postoperative pain intensity at rest and during cough at 4, 24, and 48 h postoperatively; postoperative opioid consumption and rescue analgesia requirements; subjective sleep quality within the initial 4 days after surgery; postoperative length of hospital stay; and cognitive function and mortality at 30- and 90-day follow-up.
763 studies on the registry are indexed under Emergence Delirium; 241 are open to participants now.
This study's enrollment of 520 is above the median of 120 across 475 interventional studies indexed under Emergence Delirium.
Browse Emergence Delirium studies →Affiliated Cancer Hospital & Institute of Guangzhou Medical University is the lead sponsor of 28 studies on the registry; 15 are open to participants now.
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Exclusion Criteria:
S-ketamine (50 mg, 2 ml) is diluted to 50 ml (1 mg/ml) with 48 ml normal saline;
Drug: S-ketamine
Dexmedetomidine (200 ug, 2 ml) is diluted to 100 ml (2 ug/ml) with 98 ml normal saline;
Drug: Dexmedetomidine
Loading dose: 0.25mg/kg in 10 minutes Maintenance dose: 0.1mg/kg/h
Loading dose: 0.2 ug/kg in 10 minutes Maintenance dose: 0.2 ug/kg/h
Number of Patients With Post-operative Delirium in 4 Days After Surgery
3-minute Diagnostic Confusion Assessment Method (3D-CAM)
Time frame: Within 4 days after surgery
Severity of Delirium
Confusion Assessment Method- Severity (CAM-S, Mild-to-moderate delirium will be defined as a CAM-S score of 3 to 5, while severe delirium will be defined as a CAM-S score of 6 to 7)
Time frame: Within 4 days after surgery
Duration of postoperative delirium
Positive days of postoperative delirium
Time frame: Within 4 days after surgery
Emergence delirium
Richard Agitation-Sedation Scale (RASS) (RASS score ≥ 1 indicates emergency delirium, the higher scores mean a worse outcome.)
Time frame: From 30 minutes after the arrival in the post anesthesia care unit (PACU) until the time-point of PACU discharge, assessed up to 2 hours
Pain severity
Numeric rating scale (NRS)0 = \[no pain\], 0 \< NRS \< 4 \[mild pain\], 4 ≤ NRS \< 7 \[moderate pain\], 7 ≤ NRS \<10 \[severe pain\], NRS = 10 \[worst pain imaginable\]
Time frame: Within 2 days after surgery
Quality of sleep
Numeric rating scale(0 = best-quality sleep, 10 = worst-quality sleep)
Time frame: Within 4 days after surgery
Cognitive function
Telephone interview for cognitive status-40 (TICS-40); A score below 21 will be defined as mild cognitive impairment, the higher scores mean a worse outcome.
Time frame: On postoperative day 90
Cognitive function
Telephone interview for cognitive status-40 (TICS-40); A score below 21 will be defined as mild cognitive impairment, the higher scores mean a worse outcome.
Time frame: On postoperative day 30
Postoperative opioid consumption and rescue analgesia requirements
MME
Time frame: Postoperative 48 hours
Postoperative length of hospital stay
Time frame: Postoperative length of hospital stay
Hypotension (MAP < 65 mmHg)
min
Time frame: Intraoperative
Hypertension
percent
Time frame: Intraoperative
Hypertension MAP > 120 % of baseline
Time frame: Intraoperative
Hypoxemia
SpO2 \< 90%
Time frame: Intraoperative
Bradycardia
HR\<55 bpm
Time frame: Intraoperative
Tachycardia
HR \> 100 bpm
Time frame: Intraoperative
S-ketamine-related psychomimetic side effects
dizziness, nightmares, and hallucinations
Time frame: Postoperative days 4
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Affiliated Cancer Hospital & Institute of Guangzhou Medical University