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

Not yet recruiting

Conditions

Intervention / Treatment

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

Interventional

Enrollment (Estimated)

58

Phase

  • 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 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

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
Intervention / Treatment
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

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

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

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)

August 1, 2026

Primary Completion (Estimated)

April 30, 2028

Study Completion (Estimated)

April 30, 2028

Study Registration Dates

First Submitted

July 2, 2026

First Submitted That Met QC Criteria

July 17, 2026

First Posted (Actual)

July 22, 2026

Study Record Updates

Last Update Posted (Actual)

July 22, 2026

Last Update Submitted That Met QC Criteria

July 17, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID 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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