Prognostic Value of Pulse Oximetry Differences

September 16, 2026 updated by: LEE STEPHEN GYUNG WON, Yonsei University

Prognostic Significance of Multi-site Pulse Oximetry Differences in Dyspneic Emergency Department Patients

This prospective observational study aims to evaluate whether the difference between finger, earlobe and forehead SpO₂ (ΔSpO₂) measured at emergency department (ED) presentation is associated with clinical outcomes in adult patients presenting with dyspnea. We will compare ΔSpO₂ between patients with poor outcomes (death or intensive care unit [ICU] admission) and those with favorable outcomes. Secondary objectives include assessing the prognostic value of ΔSpO₂ for mortality, ICU admission, and lactate, and comparing its predictive performance with established early warning scores.

Study Overview

Status

Recruiting

Conditions

Dyspnea

Detailed Description

This is a prospective observational cohort study conducted in a single ED to evaluate the prognostic significance of inter-site differences in pulse oximetry in adult patients presenting with dyspnea.

Adult patients (≥19 years) presenting with dyspnea and classified as Korean Triage and Acuity Scale (KTAS) levels 1-3 will be enrolled at the time of ED admission. During initial vital sign assessment at ED presentation, SpO₂ will be simultaneously measured at the finger, earlobe, and forehead, along with the corresponding perfusion index at each site.

The primary exposure of interest is the difference between finger and earlobe SpO₂ (ΔSpO₂). Additional inter-site SpO₂ differences involving forehead measurements will also be evaluated. Clinical and physiological data at presentation will be collected prospectively, while outcome data will be obtained through retrospective medical record review.

The primary outcome is the mean difference in ΔSpO₂ between patients with poor outcomes-defined as all-cause mortality from ED admission to hospital discharge or intensive care unit (ICU) admission-and those with favorable outcomes. Secondary outcomes include the associations of ΔSpO₂ with mortality, ICU admission, endotracheal intubation, serum lactate levels, and perfusion index, as well as the predictive performance of ΔSpO₂ using logistic regression and receiver operating characteristic (ROC) analysis. The prognostic value of ΔSpO₂ will also be compared with established early warning scores such as NEWS.

Study Type

Observational

Enrollment (Estimated)

400

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

Name: Stephen GW LEE, MD
Phone Number: 82-10-5124-8415
Email: leestephengyungwon@yuhs.ac

Study Locations

South Korea
- Seoul
  - Seoul, Seoul, South Korea, 03722
    - Recruiting
    - Yonsei University Severance Hospital
    - Contact:
      
      Stephen GW LEE, MD
      
      Phone Number: 82-2-2228-2678
      
      Email: LEESTEPHENGYUNGWON@YUHS.AC

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

Sampling Method

Non-Probability Sample

Study Population

We will enroll patients who meet the enrollment criteria who visit an emergency department of a tertiary teaching hospital located in Seoul, South Korea.

Description

Inclusion Criteria:

Adult patients aged 19 years or older presenting to the emergency department with dyspnea, classified as KTAS level 1-3

Exclusion Criteria:

Patients in whom SpO₂ measurements were not obtained simultaneously
Patients in whom arterial blood gas analysis was not ordered at initial evaluation
Pregnant patients
Patients with facial trauma or hand trauma
Patients with amputation, injury, or burns at the measurement sites
Patients wearing nail polish
Patients with dyshemoglobinemia
Non-Korean nationality
Patients who did not provide consent to participate in the study

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

Number of groups / cohorts

Cohorts and Interventions

Group / Cohort
Dyspnea cohort Patients visiting emergency department with dyspnea who are categorized to KTAS 1-3

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
In-hospital mortality or ICU admission Time Frame: From the index emergency department visit through hospital discharge, assessed up to 6 months.	In-hospital mortality or ICU admission of index visit	From the index emergency department visit through hospital discharge, assessed up to 6 months.

Collaborators and Investigators

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

Sponsor

Yonsei University

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 (Actual)

May 29, 2026

Primary Completion (Estimated)

March 31, 2027

Study Completion (Estimated)

April 30, 2027

Study Registration Dates

First Submitted

May 30, 2026

First Submitted That Met QC Criteria

September 16, 2026

First Posted (Actual)

September 17, 2026

Study Record Updates

Last Update Posted (Actual)