Preoperative ROX Index for Predicting Early Postoperative Hypoxemia in ENT Surgery

January 15, 2026 updated by: İlke Dolgun, Istinye University

Association of the Preoperative ROX Index With Early Postoperative Hypoxemia in Adult Patients Undergoing Elective Septorhinoplasty and Endoscopic Sinus Surgery: A Prospective Observational Study

Early postoperative hypoxemia is a frequent complication after elective ear, nose, and throat (ENT) surgery and may adversely affect recovery in the post-anesthesia care unit (PACU). Simple and non-invasive preoperative tools to identify patients at risk for early postoperative hypoxemia are limited.

The ROX index, calculated using oxygen saturation, fraction of inspired oxygen, and respiratory rate, is an easily applicable bedside parameter that has been shown to predict respiratory deterioration in various clinical settings. However, its predictive value in the preoperative period for patients undergoing elective ENT surgery has not been well established.

This prospective observational study aims to evaluate the association between the preoperative ROX index measured on room air and early postoperative hypoxemia in adult patients undergoing elective septorhinoplasty or endoscopic sinus surgery under general anesthesia. Early postoperative hypoxemia will be defined as oxygen saturation below 92% or the need for supplemental oxygen at a flow rate of 4 L/min or higher within the first 30 minutes after PACU admission. The predictive performance of the ROX index will be assessed using receiver operating characteristic (ROC) analysis.

Study Overview

Status

Status

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Not yet recruiting

Conditions

Conditions

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Intervention / Treatment

Intervention / Treatment

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Study Type

Study Type

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Observational

Enrollment (Estimated)

Enrollment

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80

Contacts and Locations

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Study Contact

Study Contact

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Study Locations

  • Turkey (Türkiye)
    • Merkez Mahallesi
      • Istanbul, Merkez Mahallesi, Turkey (Türkiye), 34250
        • Istinye University

Participation Criteria

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Eligibility Criteria

Eligibility Criteria

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Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Adult patients aged 18 to 65 years with American Society of Anesthesiologists (ASA) physical status I-II who are scheduled for elective septorhinoplasty or endoscopic sinus surgery under general anesthesia will be included in this study. All participants will undergo standard preoperative assessment, including measurement of oxygen saturation and respiratory rate on room air, and will be monitored postoperatively in the post-anesthesia care unit (PACU) according to routine clinical practice.

Description

Inclusion Criteria:

  • Age between 18 and 65 years
  • American Society of Anesthesiologists (ASA) physical status I-II
  • Scheduled for elective septorhinoplasty or endoscopic sinus surgery
  • Undergoing surgery under general anesthesia
  • Ability to undergo preoperative measurement of oxygen saturation and respiratory rate on room air
  • Provision of written informed consent

Exclusion Criteria:

  • Age <18 years or >65 years
  • ASA physical status III or higher
  • Known severe cardiopulmonary disease (e.g., advanced chronic obstructive pulmonary disease, pulmonary hypertension, severe heart failure)
  • Active respiratory tract infection in the preoperative period
  • Body mass index (BMI) >35 kg/m²
  • Requirement for long-term supplemental oxygen therapy
  • Refusal or inability to provide informed consent

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

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
Early Postoperative Hypoxemia
Time Frame: Within the first 30 minutes after admission to the post-anesthesia care unit (PACU)
Early postoperative hypoxemia will be defined as an oxygen saturation (SpO₂) below 92% or the requirement for supplemental oxygen at a flow rate of 4 L/min or higher.
Within the first 30 minutes after admission to the post-anesthesia care unit (PACU)

Collaborators and Investigators

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Sponsor

Sponsor

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Istinye University

Publications and helpful links

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General Publications

Study record dates

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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.
January 15, 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.
March 15, 2026

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 1, 2026

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).
January 7, 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.
January 7, 2026

First Posted (Estimated)

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.
January 15, 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.
January 20, 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.
January 15, 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.
January 1, 2026

More Information

Terms related to this study

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.
  • 324-2025

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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