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

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Estimated)

80

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 Locations

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

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

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

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

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

Sponsor

Istinye University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

January 15, 2026

Primary Completion (Estimated)

March 15, 2026

Study Completion (Estimated)

April 1, 2026

Study Registration Dates

First Submitted

January 7, 2026

First Submitted That Met QC Criteria

January 7, 2026

First Posted (Estimated)

January 15, 2026

Study Record Updates

Last Update Posted (Actual)

January 20, 2026

Last Update Submitted That Met QC Criteria

January 15, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Other Study ID 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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