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NCT Number: NCT07463586

Cerebral Oxygen Consumption Response to Increased Oxygen Supply and Postoperative Delirium in Older Surgical Patients

The goal of this observational study is to learn whether the brain's ability to use oxygen during surgery is associated with postoperative delirium in adults aged 65 years and older undergoing general anesthesia.

The main question it aims to answer is:

- Does reduced cerebral oxygen consumption responsiveness during surgery increase the risk of postoperative delirium in older patients?

Participants who are undergoing elective laparoscopic surgery under general anesthesia as part of their routine medical care will have brain oxygen levels measured during surgery using a non-invasive forehead sensor, and will be assessed for delirium for up to three days after surgery.

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Key information

Conditions

Delirium - Postoperative Cerebral Oxygenation Confusion Delirium Emergence Delirium Mental Disorders Nervous System Diseases Neurobehavioral Manifestations Neurocognitive Disorders Neurologic Manifestations Pathologic Processes Pathological Conditions, Signs and Symptoms Postoperative Complications Signs and Symptoms

Age range

65 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Seoul National University Bundang Hospital

Seongnam-si, Gyeonggi-do, 13620, South Korea

Location status: Recruiting

Location contact

Soowon Lee, MD, PhD

CONTACT

[email protected]

+82-31-787-7499

Who can participate

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients undergoing elective laparoscopic surgery under general anesthesia
  • Age 65 years or older

Exclusion criteria

  • Diagnosis of dementia or presence of delirium before surgery
  • Loss of capacity to provide informed consent
  • Moderate or severe cerebrovascular stenosis diagnosed before surgery
  • Moderate or severe obstructive or restrictive pulmonary dysfunction identified on preoperative pulmonary function testing
  • Requirement for supplemental oxygen therapy before surgery
  • History of neurological disorders (e.g., Parkinson's disease, stroke) or prior brain surgery
  • Severe hepatic dysfunction (AST or ALT > 120 IU/L)
  • Severe renal dysfunction (estimated GFR < 15 mL/min/1.73 m²)
  • Persistent severe hemodynamic instability (mean arterial pressure < 60 mmHg)
  • Skin conditions preventing placement of the forehead fNIRS sensor
  • Combined surgical procedures performed concurrently
  • Planned postoperative admission to the intensive care unit

Treatment and study plan

Intraoperative Cerebral Oxygen Utilization Assessment

Other

Cerebral oxygenation will be monitored intraoperatively using a non-invasive forehead sensor based on functional near-infrared spectroscopy technology. During general anesthesia, the fraction of inspired oxygen (FiO₂) may be temporarily adjusted within the standard clinical range used in routine anesthesia care to evaluate the brain's oxygen utilization response. No experimental oxygen levels or additional therapeutic interventions will be administered beyond standard clinical practice.

Primary outcomes

  1. Incidence of Postoperative Delirium

    Time frame: Up to 3 days after surgery

    Postoperative delirium diagnosed using 3D-CAM conducted in the post-anesthesia care unit and hospital ward. Delirium will be defined as at least one positive assessment during the first three postoperative days.

Secondary outcomes

  1. Intraoperative Cerebral Oxygen Utilization Response (ΔHbO-HbR)

    Time frame: During surgery

    Change in the difference between oxygenated hemoglobin (HbO) and deoxygenated hemoglobin (HbR), calculated as Δ(HbO-HbR), measured intraoperatively using functional near-infrared spectroscopy during variations in inspired oxygen concentration within the clinically applied range.

Other outcomes

  1. Predictive Performance of ΔHbO-HbR for Postoperative Delirium

    Time frame: Up to 3 days after surgery

    Predictive accuracy of intraoperative Δ(HbO-HbR) for postoperative delirium assessed using receiver operating characteristic (ROC) curve analysis. The area under the ROC curve (AUC) will be calculated to quantify discrimination.

Study contacts

Contact information is provided by the study sponsor or research team.

Soowon Lee, MD, PhD

CONTACT

[email protected]

+82-31-787-7499

Sponsors and collaborators

Lead sponsor

Seoul National University Bundang Hospital

Other

Registry information

Official study title

Association Between Cerebral Oxygen Consumption Responsiveness to Increased Oxygen Supply and Postoperative Delirium: A Prospective Observational Study Using Functional Near-Infrared Spectroscopy

Important dates

Study start
2026
Primary completion
2028
Study completion
2028
First posted
Mar 11, 2026
Registry last updated
Apr 2, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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