Cerebral Oximetry-Guided Low FiO2 Strategies in Thoracic Surgery.

Safety and Efficacy of Cerebral Oximetry-Guided Low FiO2 Strategies in Thoracic Surgery

Brief Summary (Kısa Özet)The purpose of this study is to evaluate the safety and efficacy of a cerebral oximetry-guided low fraction of inspired oxygen (FiO_2) ventilation strategy compared to a standard high FiO_2 strategy in patients undergoing elective thoracic surgery requiring one-lung ventilation (OLV).Oxygen toxicity and related postoperative pulmonary complications remain significant risks during thoracic anesthesia. While standard protocols often rely on high inspired oxygen concentrations to maintain peripheral oxygen saturation (SpO_2), this approach may induce hyperoxia. Conversely, lowering FiO_2 arbitrarily can increase the risk of hypoxemia or compromise tissue oxygenation. This prospective, parallel-group, 1:1 randomized, single-blind clinical trial aims to safely reduce intraoperative oxygen exposure by using regional cerebral oxygen saturation (rSO_2) monitoring as a physiological guide.A total of 60 participants aged 18 and older, classified as ASA I-III and scheduled for elective thoracic surgery, will be randomly assigned to one of two arms:Experimental Group (Guided Low FiO_2 Strategy): Ventilation will be initiated at a low FiO_2 of 0.5. The FiO_2 level will not be increased unless peripheral saturation (SpO_2) falls below 90% or cerebral oxygenation (rSO_2) drops below 80% of the patient's baseline value.Active Comparator Group (Standard Strategy): Patients will receive conventional anesthesia management, maintaining standard high FiO_2 levels to keep SpO_2 above 90% without cerebral oximetry guidance.The primary outcomes to be measured are the incidence of cerebral desaturation during the perioperative period and the incidence of postoperative delirium assessed via the 3D-CAM tool until hospital discharge. Secondary outcomes include intraoperative hemodynamic stability, arterial blood gas parameters (PaO_2, PaCO_2, pH, lactate), incidence of hypoxemia, total one-lung ventilation duration, postoperative cognitive dysfunction (POCD), and lengths of stay in both the intensive care unit (ICU) and the hospital.By utilizing real-time non-invasive cerebral oximetry, the study intends to demonstrate a safe ventilation protocol that minimizes oxygen toxicity without compromising cerebral oxygenation or clinical recovery outcomes.

Study Overview

• Status: Not yet recruiting
• Conditions: Anesthesia; Thoracic Surgery
• Intervention / Treatment: Procedure: Guided Low $FiO_2$ Strategy; Procedure: Standard High $FiO_2$ Strategy

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ayhan Kaydu, associate professor; Phone Number: +90 505 556 7939; Email: akaydu@hotmail.com

Study Locations

• Turkey (Türkiye)
  • Eyalet/Yerleşke
    • Diyarbakır, Eyalet/Yerleşke, Turkey (Türkiye), 21070
      • Dicle University
      • Contact: Ayhan Kaydu; Phone Number: +90 505 556 7939; Email: akaydu@hotmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients aged 18 years or older. Scheduled for elective thoracic surgery requiring one-lung ventilation (OLV). American Society of Anesthesiologists (ASA) Physical Status classification I-III.

Exclusion Criteria:

• History of cerebrovascular disease. Left ventricular ejection fraction Pulmonary hypertension. Interstitial lung disease.

Renal failure. Neuromuscular disease. Pregnancy. Expected OLV duration less than 30 minutes (< 30 min)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Low FiO2 Group; Patients undergoing elective thoracic surgery managed with a cerebral oximetry-guided low FiO_2 ventilation strategy	Procedure: Guided Low $FiO_2$ Strategy; Following general anesthesia induction, the initial $FiO_2$ will be set to 0.5. $FiO_2$ will not be increased unless the patient's pulse oximetry ($SpO_2$) drops below 90% or regional cerebral oxygen saturation ($rSO_2$) drops below 80% of its baseline value
Active Comparator: Standard Group; Patients undergoing elective thoracic surgery managed with a standard conventional ventilation strategy	Procedure: Standard High $FiO_2$ Strategy; Patients receive the standard institutional anesthesia protocol where $SpO_2$ values are strictly maintained above 90%

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Postoperative Delirium	Assessed using the 3D-CAM (Confusion Assessment Method) test	Postoperative days 1 to 3 (up to hospital discharge)
Incidence of Cerebral Desaturation	Cerebral desaturation monitored via near-infrared spectroscopy (rSO₂, %)	Perioperative period (from anesthesia induction to end of surgery, approximately up to 4 hours)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Hypoxemia	Incidence of hypoxemia defined as SpO₂ < 90% during one-lung ventilation (%)	During one-lung ventilation (OLV), approximately up to 2 hours
Mean Fraction of Inspired Oxygen (FiO₂)	Mean FiO₂ levels required to maintain adequate oxygenation during one-lung ventilation	During one-lung ventilation (OLV), approximately up to 2 hours
Mean Arterial Pressure (MAP)	Intraoperative mean arterial pressure changes monitored via standard non-invasive or invasive blood pressure measurement (mmHg)	Intraoperative period, approximately up to 4 hours
Heart Rate (HR)	Intraoperative heart rate changes monitored via standard ECG (beats per minute)	Intraoperative period, approximately up to 4 hours

Collaborators and Investigators

• Sponsor: Dicle University

Study record dates

Study Major Dates

• Study Start (Estimated): June 15, 2026
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): August 15, 2026

Study Registration Dates

• First Submitted: June 11, 2026
• First Submitted That Met QC Criteria: June 16, 2026
• First Posted (Actual): June 22, 2026

Study Record Updates

• Last Update Posted (Actual): June 22, 2026
• Last Update Submitted That Met QC Criteria: June 16, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 74/2026

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No