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The Effects of Subanesthetic S-ketamine on Postoperative Delirium and Cognitive Function in the Elderly Undergoing Non-cardiac Thoracic Surgery

The Effects of Subanesthetic S-ketamine on Postoperative Delirium and Cognitive Function in the Elderly Undergoing Non-cardiac Thoracic Surgery: a Protocol for Randomized, Double-blinded, Positive-controlled, Non-inferiority Trial

Status
Completed
Phases
Early Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05242692
Acronym
SKED
Enrollment
520
Registered
2022-02-16
Start date
2022-06-10
Completion date
2025-08-31
Last updated
2026-05-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Elderly Patients, Postoperative Delirium

Keywords

Postoperative delirium, S-ketamine, Dexmedetomidine, elderly patients

Brief summary

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.

Detailed description

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.

Interventions

DRUGS-ketamine

Loading dose: 0.25mg/kg in 10 minutes Maintenance dose: 0.1mg/kg/h

DRUGDexmedetomidine

Loading dose: 0.2 ug/kg in 10 minutes Maintenance dose: 0.2 ug/kg/h

Sponsors

Affiliated Cancer Hospital & Institute of Guangzhou Medical University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Masking description

The labeled "Study medication" syringes (50ml) in identical appearance, and the infusion regimen formulated by the pharmacist based on the randomization, will be distributed to the attending anesthesiologists responsible for anesthetic management as soon as the research team informs the central pharmacy about the patient heading for surgery. To avoid anesthesiologists' speculation about the randomized assignment, the study drugs will be infused at a similar rate. The anesthesiologists, the patients, the investigators responsible for follow-up, and the statisticians are all masked to randomized allocations until the final statistical analyses are completed. The blindness will be unmasked by the primary investigator in a medical emergency including deterioration of patient's condition intraoperatively or adverse events postoperatively.

Eligibility

Sex/Gender
ALL
Age
60 Years to 90 Years
Healthy volunteers
No

Inclusion criteria

* Aged 60 years or over * Both genders * American anesthesiologist association (ASA) physical status classificationⅠ-Ⅲ * Diagnosed with lung, esophagus, or mediastinum disorders * Undergoing open or video-assisted thoracic surgery including lobectomy, segmentectomy, pneumonectomy, esophagectomy, or resection of mediastinal tumor * General anesthesia with one-lung ventilation (OLV) or bronchial blocker. * An expected operation duration of 2 hours or more. * Voluntarily participate in the trial and sign informed consent.

Exclusion criteria

* History of psychiatric disease or severe depression * History of glaucoma or hyperthyroidism * History of severe hepatic (Child-Pugh grade C) or renal (requirement for renal replacement therapy) disorder. * Body mass index (BMI) greater 35 kg/m2 * Dementia history or baseline Mini-Mental State Examination (MMSE) score less than 23 * Severe audio-visual impairments, or inability to speak Mandarin or Cantonese precluding communication * Sinus bradycardia (heart rate \< 50 beats per minutes, bpm), sick sinus or Wolff- Parkinson-White syndromes, or Ⅱ degree atrioventricular block and over * Poorly controlled hypertension (resting systolic blood pressure over 180 mm Hg, or resting diastolic blood pressure over 100 mm Hg) * Allergic to dexmedetomidine, S-ketamine or any of their formulation ingredients; * Taking sedatives, antidepressants or glucocorticoids * Alcohol or drug abuser * Life expectancy of less than 2 months due to extensive tumor metastasis.

Design outcomes

Primary

MeasureTime frameDescription
Number of Patients With Post-operative Delirium in 4 Days After SurgeryWithin 4 days after surgery3-minute Diagnostic Confusion Assessment Method (3D-CAM)

Secondary

MeasureTime frameDescription
Severity of DeliriumWithin 4 days after surgeryConfusion 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)
Duration of postoperative deliriumWithin 4 days after surgeryPositive days of postoperative delirium

Countries

China

Contacts

STUDY_CHAIRYihua Li, PhD

Cancer hospital and institute of Guangzhou medical university

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: May 2, 2026