Long-term Follow-up of Dexmedetomidine-esketamine and tDCS for Neurocognitive Complications After Surgery

Phase 4Not Yet RecruitingNCT07576543

Peking University First Hospital1,160 enrolled

Overview

Neurocognitive complications, mainly delirium and neurocognitive disorders, are common cerebral complications in older patients after surgery and associated with worse long-term outcomes. An ongoing 2×2 factorial trial conducted by the investigators plan to test the effects of perioperative dexmedetomidine-esketamine combination and transcranial direct current stimulation (tDCS) on postoperative neurocognitive complications in older patients. This long-term follow-up of the ongoing trial aims to investigate the effects of perioperative dexmedetomidine-esketamine combination and tDCS on long-term outcomes in older patients after noncardiac surgery.

Neurocognitive complications, mainly delirium and neurocognitive disorders, are common cerebral complications in older patients after surgery. Occurrence of neurocognitive complications is associated with prolonge hospital stay and increased in-hospital death. Furthermore, occurrence of neurocognitive complications is associated with adverse long-term outcomes, including cognitive decline, poor quality of life, and reduced long-term survival. Dexmedetomidine is a highly selective alpha 2 adrenergic receptor agonist with sedative, analgesic, and anxiolytic effects. Available evidence showed that perioperative dexmedetomidine decreased early postoperative neurocognitive complications in older patients, possibly by improving analgesia and sleep quality and relieving surgery-related inflammation. However, routine dose dexmedetomidine increases bradycardia and hypotension which are potentially harmful to older patients. Ketamine is a noncompetitive N-Methyl-D-aspartic acid (NMDA) receptor antagonist and has been used as an anesthetic and analgesic for decades. Esketamine is the S-enantiomer of ketamine and twice as potent as racemic ketamine. Recent studies found that subanesthetic dose of esketamine is effective in improving analgesia and sleep quality and relieving surgery-related stress response. However, even subanesthetic ketamine or esketamine increases neuropsychiatric side effects. In clinical practice, dexmedetomidine-esketamine combination has been used for premedication in children and postoperative analgesia in adults and showed additive or synergistic effects. An ongoing trial conducted by the investigators plan to test the hypothesis that perioperative use of dexmedetomidine-esketamine combination may prevent postoperative neurocognitive complications in older patients. It is reasonable to hypothesize that perioperative dexmedetomdine-esketamine might also have favorable effects on long-term outcomes. Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique and increasingly used for treatment of various neurological diseases. Studies in the perioperative settings showed that perioperative use of tDCS improved sleep quality and reduced delirium occurrence early after surgery. The ongoing trial coducted by the investigators plan to test the hypothesis that perioperative use of tDCS may reduce postoperative neurocognitive complications in older patients. Perioperative tDCS might also have favorable effects on long-term outcomes. This long-term follow-up of the ongoing 2×2 factorial trial aims to investigate the effects of perioperative dexmedetomidine-esketamine combination and tDCS on long-term outcomes in older patients after noncardiac surgery.

Interventions

Dex-EskDRUG

Dexmedetomidine-esketamine combination (1 μg/mL dexmedetomidine and 0.5 mg/mL esketamine) will be administered after anesthesia induction, firstly as a loading dose at a rate of \[0.4 x body weight (kg)\] mL/h for 30 minutes (0.2 μg/kg dexmedetomidine and 0.1 mg/kg esketamine), followed by a maintenance infusion at a rate of \[0.1 x body weight (kg)\] mL/h (0.1 μg/kg/h dexmedetomidine and 0.05 mg/kg/h esketamine) until one hour before expected end surgery. Postoperative patient-controlled analgesia will be established with a 100 mL mixture (containing 1.0 μg/mL sufentanil, 1.25 μg/mL dexmedetomidine, and 0.25 mg/mL esketamine in normal saline), programmed to deliver 2-mL boluses with an 8-minute lockout interval and an 1-mL/h background infusion, and provided for 48 hours (at least 24 hours).

PlaceboDRUG

Placebo (normal saline) will be administered after anesthesia induction, firstly as a loading dose at a rate of \[0.4 x body weight (kg)\] mL/h for 30 minutes, followed by a maintenance infusion at a rate of \[0.1 x body weight (kg)\] mL/h until one hour before expected end surgery. Postoperative patient-controlled analgesia will be established with a 100 mL mixture (containing 1.0 μg/mL sufentanil in normal saline), programmed to deliver 2-mL boluses with an 8-minute lockout interval and an 1-mL/h background infusion, and provided for 48 hours (at least 24 hours).

Active tDCSDEVICE

Active transcranial direct current stimulation (tDCS) will be administered using a battery-powered stimulator. The anode will be positioned over the left dorsolateral prefrontal cortex (DLPFC, F3) and the cathode over the right supraorbital region (Fp2). The stimulation intensity will be set at 2.0 mA, featuring a 30-second linear ramp-up at the beginning and a 30-second ramp-down at the end of each session. Each participant will receive a total of three 20-minute sessions of active tDCS. The first session will be provided at 40 minutes after extubation in the post-anesthesia care unit. Two other sessions will be provided on postoperative days 1 and 2 (between 10:00 and 12:00 am).

Sham tDCSDEVICE

Sham transcranial direct current stimulation (tDCS) will be administered using a battery-powered stimulator. The anode will be positioned over the left dorsolateral prefrontal cortex (DLPFC, F3) and the cathode over the right supraorbital region (Fp2). To ensure blinding, the device will deliver a initial 30-second ramp-up to 2.0 mA followed immediately by a 30-second ramp-down to 0 mA. The device remains "ON" for the remaining 19 minutes with no effective current output, mimicking the peripheral scalp sensation without delivering cortical modulation. Each participant will receive a total of three 20-minute sessions of sham tDCS. The first session will be provided at 40 minutes after extubation in the post-anesthesia care unit. Two other sessions will be provided on postoperative days 1 and 2 (between 10:00 and 12:00 am).

Eligibility

Sex: ALLMin age: 65 YearsMax age: 90 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Aged 65 to 90 years; * Preoperative Mini-Mental State Examination (MMSE) score \< 27 points, indicating possible cognitive impairment ranging from mild to moderate; * Scheduled to undergo elective non-cardiac, non-neurosurgical surgery under general anesthesia, with an expected surgical duration \> 1 hour; * Required patient-controlled intravenous analgesia (PCIA) after surgery. Exclusion Criteria: * Preoperative inability to communicate due to coma, severe dementia, endstage disease, or language impairment; * History of schizophrenia, epilepsy, Parkinson's disease, brain trauma/surgery, or myasthenia gravis; * Presence of metal implants in the intracranial or cervical region (such as cochlear implants, aneurysm clips, deep brain stimulation electrodes), or skin damage or severe skin disease on the head; * Severe cardiac dysfunction (left ventricular ejection fraction \< 30%), comorbid with sick sinus syndrome, severe bradycardia (heart rate \< 50 bpm), or second-degree or higher atrioventricular block, or implantation of a cardiac pacemaker; * Uncontrolled hyperthyroidism or pheochromocytoma; * Severe liver dysfunction (Child-Pugh class C), severe renal dysfunction (requiring dialysis), or ASA classification ≥ IV; * Allergy to dexmedetomidine or esketamine; * Participation in other clinical studies within the past 3 months; * Other conditions that are deemed unsuitable for study participation.

Locations (6)

Peking University First Hospital

Beijing, Beijing Municipality, China

Fujian Medical University Union Hospital

Fuzhou, Fujian, China

Peking University Shenzhen Hospital

Shenzhen, Guangdong, China

Xijing Hospital, Air Force Medical University

Xi'an, Shaanxi, China

First Affilited Hospital, School of Medicine, Zhejiang University

Hangzhou, Zhejiang, China

Second Affilited Hospital, School of Medicine, Zhejiang University

Hangzhou, Zhejiang, China

Outcomes

Primary Outcomes

Incidence of postoperative neurocognitive disorders (pNCD) at 3 months

Cognitive function will be assessed at baseline and at 3 months after surgery using the Telephone version of Montreal Cognitive Assessment (T-MoCA; scores range from 0 to 22, with higher scores indicating better cognitive function）. Postoperative neurocognitive disorders (pNCD) is defined as: a \|Z\| value of decline in T-MoCA score ≥1.96. Z value = \[(change from baseline in T-MoCA score in a surgical patient - mean change from baseline in T-MoCA scores in the non-surgical group)\] / (standard deviation of change from baseline in T-MoCA scores in the non-surgical group).

Time frame: At 3 months after surgery

Secondary Outcomes

Event-free survival

Time interval from index surgery to cancer recurrence/metastasis/progression, new-onset cancer, new-onset serious illness (requiring hospitalization), or all-cause death, whichever comes first.

Time frame: Up to 1 year after surgery of the last enrolled patient