One Lung Ventilation in Thoracic SurgeryNCT07359833
Oxygen Reserve Index Guided FiO₂ Titration in One-Lung Ventilation
A study testing Oxygen Reserve Index (ORi)-guided oxygen titration in people with One Lung Ventilation in Thoracic Surgery, run by Gazi University at 1 site in Turkey (Türkiye).
Trial summary
One-lung ventilation (OLV) is routinely used during thoracic surgery to facilitate surgical exposure but is associated with an increased risk of intraoperative hypoxemia. To prevent hypoxia, high fractions of inspired oxygen (FiO₂) are commonly administered; however, excessive oxygen delivery may lead to hyperoxia and… Read more about this study
- Who is it for?
- Ages 18 to 85 years
- Conditions the study is for
- One Lung Ventilation in Thoracic Surgery
- What is being tested?
- Oxygen Reserve Index (ORi)-guided oxygen titration
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 5 Aug 2022to 30 Aug 2023
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients age between 18-85 years Elective case Thoracic surgeries performed with one-lung ventilation using a double-lumen endotracheal tube Left ventricule ejection fraction(LVEF)>45%
Who cannot join
- heart failure (LVEF) < 45% severe valvular disease admission as an emergency case history of prior lung resection presence of peripheral arterial disease.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effects of FiO2 Adjustment on Hyperoxia Biomarkers and Postoperative Complications Using Oxygen Reserve Index During One-lung Ventilation
One-lung ventilation (OLV) is routinely used during thoracic surgery to facilitate surgical exposure but is associated with an increased risk of intraoperative hypoxemia. To prevent hypoxia, high fractions of inspired oxygen (FiO₂) are commonly administered; however, excessive oxygen delivery may lead to hyperoxia and oxidative tissue injury. The Oxygen Reserve Index (ORi) is a novel, noninvasive monitoring parameter that provides real-time information on moderate hyperoxia and may allow more precise titration of FiO₂ during anesthesia.
The aim of this prospective, randomized clinical trial is to evaluate whether ORi-guided intraoperative oxygen management can reduce oxygen exposure during OLV without increasing hypoxemia and to assess its effects on oxidative stress biomarkers and postoperative outcomes. Adult patients undergoing elective thoracic surgery with OLV are randomized to receive either ORi-guided FiO₂ titration or conventional oxygen management. Oxidative stress biomarkers and postoperative pulmonary complications are compared between groups.
Read the detailed description
One-lung ventilation is an essential component of thoracic anesthesia but poses significant challenges in maintaining adequate oxygenation. In clinical practice, high FiO₂ levels are often applied to prevent hypoxemia; however, prolonged exposure to hyperoxia has been associated with increased oxidative stress, inflammatory responses, and potential tissue damage. Despite growing awareness of oxygen toxicity, optimal intraoperative oxygen titration strategies during OLV remain poorly defined.
The Oxygen Reserve Index is derived from multiwavelength pulse oximetry and provides continuous, noninvasive information on moderate hyperoxia (corresponding to arterial oxygen tensions above normoxia but below severe hyperoxia). ORi monitoring may enable anesthesiologists to titrate FiO₂ more precisely, thereby avoiding unnecessary oxygen exposure while maintaining adequate oxygenation.
In this prospective, randomized clinical trial, adult patients scheduled for elective thoracic surgery requiring OLV are allocated to either an ORi-monitored group or a control group. In the ORi group, FiO₂ is adjusted intraoperatively according to predefined ORi thresholds, whereas in the control group FiO₂ is managed according to standard clinical practice based on pulse oximetry. Blood and tracheal aspirate samples are collected preoperatively and at predefined postoperative time points to measure interleukin-6, superoxide dismutase, and malondialdehyde levels as markers of inflammation and oxidative stress. Postoperative pulmonary complications and surgical site infections are recorded during intensive care unit and ward follow-up.
This study aims to determine whether ORi-guided oxygen titration during OLV can safely reduce intraoperative oxygen exposure and to clarify its impact on biochemical markers of oxidative stress and clinical outcomes such as postoperative pulmonary complications and surgical site infection.
- Conditions
- One Lung Ventilation in Thoracic Surgery
- Being tested
- Oxygen Reserve Index (ORi)-guided oxygen titration
- Keywords
- One-Lung Ventilation, oxygen reserve index, Hyperoxia, Thoracic surgery, Oxidative stress, Oxygen
- Medical subject headings
- Hyperoxia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Oxygen Reserve Index (ORi)-guided oxygen titrationDevice
FiO₂ adjusted intraoperatively according to predefined ORi thresholds during thoracic surgery and one lung ventilation period.
| Study group | Role | What they receive |
|---|---|---|
| ORi group. | Experimental | In this group, intraoperative FiO₂ was titrated according to predefined Oxygen Reserve Index (ORi) thresholds during one-lung ventilation and all intraoperative period, with the aim of maintaining adequate oxygenation while avoiding unnecessary hyperoxia. Receives: Device: Oxygen Reserve Index (ORi)-guided oxygen titration |
| Non-ORi group | No intervention | In this group, intraoperative FiO₂ was adjusted based solely on pulse oximetry (SpO₂) monitoring, without the use of Oxygen Reserve Index (ORi) guidance. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean intraoperative FiO₂
The primary outcome is the mean fraction of inspired oxygen (FiO₂) administered during one-lung ventilation and throughout the entire duration of surgery, recorded continuously intraoperatively and compared between the ORi-guided and conventional oxygen management groups.
Measured: From anesthesia induction to the extubation
Secondary outcomes (3)
Oxidative stress biomarkers (IL-6, SOD, MDA)
Changes in serum and tracheal aspirate levels of interleukin-6, superoxide dismutase, and malondialdehyde assessed at four time points. Serum biomarker levels are measured at anesthesia induction and at the 12th and 24th postoperative hours, while tracheal aspirate biomarker levels are measured at extubation. Results are compared between the ORi and Non-ORİ groups.
Measured: Anesthesia induction, extubation, postoperative 12th hour, postoperative 24th hour
Postoperative pulmonary complications
Incidence of postoperative pulmonary complications, including prolonged drainage, hemothorax, bronchopleural fistula, reintubation, atelectasis, bronchopneumonia, and acute respiratory distress syndrome, assessed during intensive care unit and ward follow-up.
Measured: up to 2 weeks
Surgical site infections
Incidence of surgical site infections recorded during postoperative hospital stay.
Measured: up to 2 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Jan 2026
- Study start5 Aug 2022
- Primary completion15 Jul 2023
- Study completion30 Aug 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for One Lung Ventilation in Thoracic SurgeryStudies of the same condition, open and under way.
- More trials run by Gazi UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- A prospective, randomized, parallel-group clinical trial comparing ORi-guided intraoperative FiO₂ titration with conventional oxygen management in adult patients undergoing thoracic surgery with one-lung ventilation.
- Masking
- None (open label)
- Enrolment
- 60 participants (actual)
Sponsor and investigators
- Lead sponsor
- Gazi University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Bugra AYKENAR, Gazi University
- Investigators
- Buğra Aykenar, Principal investigator, Gazi University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07359833
- Sponsor's protocol ID
- GaziU-AR-BA-01
- Status last verified
- Aug 2022
- First submitted
- 17 Jan 2026
- Last updated
- 22 Jan 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No: The data generated during this study may be made available for use in future meta-analyses upon reasonable request to the corresponding author.
Publications
Saracoglu A, Yamansavci Sirzai E, Yildizeli B, Yuksel M, Aykac ZZ. Oxygen reserve index guided oxygen titration in one lung ventilation with low fresh gas flow. Turk J Med Sci. 2021 Oct 21;51(5):2413-2419. doi: 10.3906/sag-2009-149.
PubMed 34051711Aykenar B, Ayhan A, Issi S, Kilic MD, Zeyneloglu P. Effects of FiO2 adjustment on hyperoxia biomarkers and postoperative complications using oxygen reserve index during one-lung ventilation. BMC Anesthesiol. 2026 Jun 15. doi: 10.1186/s12871-026-04020-6. Online ahead of print.
PubMed 42289654
Study at a glance
From the registry record, last updated by the sponsor on 22 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of FiO2 Adjustment on Hyperoxia Biomarkers and Postoperative Complications Using Oxygen Reserve Index During One-lung Ventilation
- ClinicalTrials.gov ID
- NCT07359833
- Acronym / sponsor ID
- GaziU-AR-BA-01
- Conditions
- One Lung Ventilation in Thoracic Surgery
- Keywords
- One-Lung Ventilation, oxygen reserve index, Hyperoxia, Thoracic surgery, Oxidative stress, Oxygen
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 60 participants (actual)
- Lead sponsor
- Gazi UniversityUniversity, hospital or other
- Study start
- 5 Aug 2022 (actual)
- Primary completion
- 15 Jul 2023 (actual)
- Study completion
- 30 Aug 2023 (actual)
- First posted
- 22 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
One-lung ventilation (OLV) is routinely used during thoracic surgery to facilitate surgical exposure but is associated with an increased risk of intraoperative hypoxemia. To prevent hypoxia, high fractions of inspired oxygen (FiO₂) are commonly administered; however, excessive oxygen delivery may lead to hyperoxia and oxidative tissue injury. The Oxygen Reserve Index (ORi) is a novel, noninvasive monitoring parameter that provides real-time information on moderate hyperoxia and may allow more precise titration of FiO₂ during anesthesia.
The aim of this prospective, randomized clinical trial is to evaluate whether ORi-guided intraoperative oxygen management can reduce oxygen exposure during OLV without increasing hypoxemia and to assess its effects on oxidative stress biomarkers and postoperative outcomes. Adult patients undergoing elective thoracic surgery with OLV are randomized to receive either ORi-guided FiO₂ titration or conventional oxygen management. Oxidative stress biomarkers and postoperative pulmonary complications are compared between groups.
Detailed description
One-lung ventilation is an essential component of thoracic anesthesia but poses significant challenges in maintaining adequate oxygenation. In clinical practice, high FiO₂ levels are often applied to prevent hypoxemia; however, prolonged exposure to hyperoxia has been associated with increased oxidative stress, inflammatory responses, and potential tissue damage. Despite growing awareness of oxygen toxicity, optimal intraoperative oxygen titration strategies during OLV remain poorly defined.
The Oxygen Reserve Index is derived from multiwavelength pulse oximetry and provides continuous, noninvasive information on moderate hyperoxia (corresponding to arterial oxygen tensions above normoxia but below severe hyperoxia). ORi monitoring may enable anesthesiologists to titrate FiO₂ more precisely, thereby avoiding unnecessary oxygen exposure while maintaining adequate oxygenation.
In this prospective, randomized clinical trial, adult patients scheduled for elective thoracic surgery requiring OLV are allocated to either an ORi-monitored group or a control group. In the ORi group, FiO₂ is adjusted intraoperatively according to predefined ORi thresholds, whereas in the control group FiO₂ is managed according to standard clinical practice based on pulse oximetry. Blood and tracheal aspirate samples are collected preoperatively and at predefined postoperative time points to measure interleukin-6, superoxide dismutase, and malondialdehyde levels as markers of inflammation and oxidative stress. Postoperative pulmonary complications and surgical site infections are recorded during intensive care unit and ward follow-up.
This study aims to determine whether ORi-guided oxygen titration during OLV can safely reduce intraoperative oxygen exposure and to clarify its impact on biochemical markers of oxidative stress and clinical outcomes such as postoperative pulmonary complications and surgical site infection.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- A prospective, randomized, parallel-group clinical trial comparing ORi-guided intraoperative FiO₂ titration with conventional oxygen management in adult patients undergoing thoracic surgery with one-lung ventilation.
| Arm | Type | Receives |
|---|---|---|
| ORi group. | Experimental | Device: Oxygen Reserve Index (ORi)-guided oxygen titrationIn this group, intraoperative FiO₂ was titrated according to predefined Oxygen Reserve Index (ORi) thresholds during one-lung ventilation and all intraoperative period, with the aim of maintaining adequate oxygenation while avoiding unnecessary hyperoxia. |
| Non-ORi group | No intervention | –In this group, intraoperative FiO₂ was adjusted based solely on pulse oximetry (SpO₂) monitoring, without the use of Oxygen Reserve Index (ORi) guidance. |
Who may qualify
- Ages
- 18 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Patients age between 18-85 years Elective case Thoracic surgeries performed with one-lung ventilation using a double-lumen endotracheal tube Left ventricule ejection fraction(LVEF)>45%
Key exclusion criteria (1 listed)
- heart failure (LVEF) < 45% severe valvular disease admission as an emergency case history of prior lung resection presence of peripheral arterial disease.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Oxygen Reserve Index (ORi)-guided oxygen titrationFiO₂ adjusted intraoperatively according to predefined ORi thresholds during thoracic surgery and one lung ventilation period. | Device | ORi group. |
Primary outcome
Mean intraoperative FiO₂
Time frame: From anesthesia induction to the extubation
The primary outcome is the mean fraction of inspired oxygen (FiO₂) administered during one-lung ventilation and throughout the entire duration of surgery, recorded continuously intraoperatively and compared between the ORi-guided and conventional oxygen management groups.
3 secondary outcomes
Oxidative stress biomarkers (IL-6, SOD, MDA)
Time frame: Anesthesia induction, extubation, postoperative 12th hour, postoperative 24th hour
Postoperative pulmonary complications
Time frame: up to 2 weeks
Surgical site infections
Time frame: up to 2 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Jan 2026.
- Results publication: PubMed 34051711Saracoglu A, Yamansavci Sirzai E, Yildizeli B, Yuksel M, Aykac ZZ. Oxygen reserve index guided oxygen titration in one lung ventilation with low fresh gas flow. Turk J Med Sci. 2021 Oct 21;51(5):2413-2419. doi: 10.3906/sag-2009-149.
- Derived from this study: PubMed 42289654Aykenar B, Ayhan A, Issi S, Kilic MD, Zeyneloglu P. Effects of FiO2 adjustment on hyperoxia biomarkers and postoperative complications using oxygen reserve index during one-lung ventilation. BMC Anesthesiol. 2026 Jun 15. doi: 10.1186/s12871-026-04020-6. Online ahead of print.
- Individual participant dataSharing planned: No. The data generated during this study may be made available for use in future meta-analyses upon reasonable request to the corresponding author.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Buğra Aykenar principal investigator
Gazi University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Oxygen Reserve Index (ORi)-guided oxygen titration in people with One Lung Ventilation in Thoracic Surgery, run by Gazi University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 22 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Mean intraoperative FiO₂ (time frame: From anesthesia induction to the extubation). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07359833, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Jan 2026.