ORI-Guided Oxygen Therapy During One-Lung Ventilation (ORI-OLV)

July 17, 2026 updated by: Tae-Yop Kim, MD PhD, Konkuk University Medical Center

Effect of Oxygen Reserve Index-Guided Fraction of Inspired Oxygen Titration on the Incidence of Hyperoxemia During One-Lung Ventilation

High inspired oxygen concentrations (FiO₂) are commonly administered during general anesthesia to prevent hypoxemia. However, excessive oxygen administration may result in hyperoxemia, which has been associated with impaired hypoxic pulmonary vasoconstriction, increased oxidative stress, ventilation-perfusion mismatch, and postoperative pulmonary complications.

During one-lung ventilation (OLV) for thoracic surgery, higher FiO₂ is often required because of increased intrapulmonary shunting, making hyperoxemia a frequent occurrence. The Oxygen Reserve Index (ORI) is a noninvasive pulse oximetry-derived parameter that reflects moderate hyperoxemia (PaO₂ approximately 100-200 mmHg) and may facilitate more precise oxygen titration than pulse oximetry alone.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This prospective, randomized, assessor-blinded clinical trial aims to determine whether FiO₂ titration guided by both ORI and peripheral oxygen saturation (SpO₂) reduces the incidence of hyperoxemia compared with conventional SpO₂-guided FiO₂ titration during OLV in patients undergoing thoracic surgery. Participants will be randomly assigned to either an ORI-guided group or a conventional SpO₂-guided group. The primary outcome is the incidence of hyperoxemia (PaO₂ >125 mmHg) after OLV. Secondary outcomes include SpO₂, ORI, PaO₂, and FiO₂ measured

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
58

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • South Korea
    • Gwangjin-gu
      • Seoul, Gwangjin-gu, South Korea, 05030
        • Konkuk University Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults aged ≥19 years
  • Scheduled for elective lung surgery requiring one-lung ventilation
  • Written informed consent

Exclusion Criteria:

  • Severe pulmonary hypertension.
  • Left ventricular systolic dysfunction.

Withdrawal Criteria:

  • The participant or legally authorized representative requests withdrawal from the study.
  • An adverse event occurs that precludes continued participation in the study.
  • The planned surgery or study procedures are not performed (e.g., ORI monitoring is not applied or arterial blood gas analysis is not performed).
  • Perfusion Index is less than 2 during the study.
  • A major violation of the inclusion or exclusion criteria is identified after enrollment.
  • The participant fails to comply with the study protocol, potentially affecting the validity of the study outcomes.
  • Continued participation is considered not to be in the participant's best interest.
  • In the investigator's judgment, any other condition arises that makes continued participation inappropriate.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: ORI-Guided FiO2 Titration
Fraction of inspired oxygen (FiO₂) is titrated using both the Oxygen Reserve Index (ORI) and peripheral oxygen saturation (SpO₂) during one-lung ventilation.
Other: ORI-Guided FiO2 Titration
During one-lung ventilation, FiO₂ is adjusted according to both ORI and SpO₂. FiO₂ is titrated to maintain SpO₂ ≥98% while keeping ORI above 0 to minimize hyperoxemia.
Active Comparator: Conventional SpO₂-Guided FiO₂ Titration
Fraction of inspired oxygen (FiO₂) is titrated using peripheral oxygen saturation (SpO₂) alone according to the institutional standard of care during one-lung ventilation.
Other: Conventional SpO₂-Guided FiO₂ Titration
During one-lung ventilation, FiO₂ is adjusted according to SpO₂ alone. FiO₂ is titrated to maintain SpO₂ ≥98% according to the institutional standard of care.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Incidence of hyperoxemia during one-lung ventilation
Time Frame: 10 min after initiation of one-lung ventilation during operation
Hyperoxemia is defined as an arterial partial pressure of oxygen (PaO₂) greater than 125 mmHg measured after initiation of one-lung ventilation.
10 min after initiation of one-lung ventilation during operation

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Peripheral oxygen saturation (SpO₂)
Time Frame: 10 mins after two-lung ventilation, 10 mins after initiation of one-lung ventilation, and 10 mins after resumption of two-lung ventilation, all time frames are included in anesthesia time
Peripheral oxygen saturation
10 mins after two-lung ventilation, 10 mins after initiation of one-lung ventilation, and 10 mins after resumption of two-lung ventilation, all time frames are included in anesthesia time
Oxygen Reserve Index (ORI)
Time Frame: 10 mins after two-lung ventilation, 10 mins after initiation of one-lung ventilation, and 10 mins after resumption of two-lung ventilation, all time frames are included in anesthesia time
Oxygen Reserve Index measured during anesthesia.
10 mins after two-lung ventilation, 10 mins after initiation of one-lung ventilation, and 10 mins after resumption of two-lung ventilation, all time frames are included in anesthesia time
Arterial oxygen tension (PaO₂)
Time Frame: 10 mins after two-lung ventilation, 10 mins after initiation of one-lung ventilation, and 10 mins after resumption of two-lung ventilation, all time frames are included in anesthesia time
Arterial partial pressure of oxygen measured by arterial blood gas analysis.
10 mins after two-lung ventilation, 10 mins after initiation of one-lung ventilation, and 10 mins after resumption of two-lung ventilation, all time frames are included in anesthesia time
Fraction of inspired oxygen (FiO₂)
Time Frame: 10 mins after two-lung ventilation, 10 mins after initiation of one-lung ventilation, and 10 mins after resumption of two-lung ventilation, all time frames are included in anesthesia time
Fraction of inspired oxygen administered during anesthesia.
10 mins after two-lung ventilation, 10 mins after initiation of one-lung ventilation, and 10 mins after resumption of two-lung ventilation, all time frames are included in anesthesia time

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Konkuk University Medical Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 30, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 30, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 2, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 17, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 22, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 22, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 17, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • KUMC 2026-05-061

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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