A Simple Clinical Tool to Help Diagnose Pulmonary Embolism: Phase 1

March 25, 2025 updated by: Scott Keller, Mayo Clinic
The goal of this project is to determine if the change in oxygen saturation during deep inspiration ("augmented pulse oximetry") can be used as a method to rule out pulmonary embolism (PE). The investigators propose to evaluate a simple, non-invasive clinical tool to help rule out PE. The investigators plan to measure the oxygen saturation of 40 consecutive patients with newly-diagnosed PE (within 60 minutes of diagnosis) and 80 matched controls who do not have a PE. Trained, blinded Respiratory Therapists or Study Coordinators will record each patient's oxygen saturation before, during, and after a 2-minute period of deep inspirations (vital capacity [the maximal amount of air that can be inhaled, measured in milliliters]) using an incentive spirometer. The investigators' central hypothesis is that persons with a PE will not respond to augmented pulse oximetry and will not significantly improve or normalize their oxygen saturation.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

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

Patients will be identified and enrolled by the Mayo Clinic St. Marys Emergency Department staff as they are undergoing medical care in the Emergency Department.

The investigators will calculate the difference in oxygen saturation pre- and post-deep inspiration (ΔSpO2 at 1 minute, 2 minutes and 4 minutes), and then correlate these values with the CT result.

In cases of PE, The investigators expect the SpO2 to remain unchanged, or to change less than 3-5%. The investigators expect alternate hypoxemic conditions to have a significantly greater increase in SpO2.

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 (Actual)

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.
64

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 Locations

  • United States
    • Minnesota
      • Rochester, Minnesota, United States, 55905
        • Mayo Clinic

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

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • 18 years of age or greater.
  • Agrees and able to participate in the study.
  • Room air SpO2 (oxygen saturation) less than 92% and newly-diagnosed PE (or controls with no PE) based on CT angiogram result.

Exclusion Criteria:

  • Clinical concern for instability.
  • Systolic blood pressure less than 100 mm Hg.
  • Heart rate ≥140 beats per minute.
  • Oxygen saturation less than 85% with more than 4 L supplemental oxygen.
  • Unable to participate/comply with instructions for using the incentive spirometer.
  • Patients from the Federal Medical Center in Rochester, Minnesota.
  • Patients who do not speak English (due to the need for expediency).

Patients will be under the care of the Emergency Department team who have the skills and resources to monitor and treat patients if they were to become unstable.

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: Diagnostic
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

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: Proven pulmonary embolism.
Augmented pulse oximetry using incentive spirometer. Emergency Department patients with pulmonary embolism.
Other: Augmented pulse oximetry using incentive spirometer.
Augmented pulse oximetry using incentive spirometer.
Device: Incentive spirometer.
The incentive spirometer is a simple passive device that measures the amount of air a person can inhale.
Other Names:
  • AirLife Volumetric Incentive Spirometer.
Other: Control patients
Augmented pulse oximetry using incentive spirometer. Emergency Department patients who do not have pulmonary embolism.
Other: Augmented pulse oximetry using incentive spirometer.
Augmented pulse oximetry using incentive spirometer.
Device: Incentive spirometer.
The incentive spirometer is a simple passive device that measures the amount of air a person can inhale.
Other Names:
  • AirLife Volumetric Incentive Spirometer.

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
Change in oxygen saturation using augmented pulse oximetry for patients with and without pulmonary embolism.
Time Frame: Oxygen saturation (SpO2) will be recorded prior to using the spirometer, at 1 minute (during use of the spirometer), at 2 minutes (at the end of using the spirometer), and at 4 minutes.
Trained, blinded Respiratory Therapists or Study Coordinators will record each patient's oxygen saturation before, during, and after a 2-minute period of deep inspirations (vital capacity) using an incentive spirometer. The investigators will calculate the difference in oxygen saturation pre- and post-deep inspiration (ΔSpO2 at 1 minute, 2 minutes and 4 minutes), and then correlate these values with the CT result.
Oxygen saturation (SpO2) will be recorded prior to using the spirometer, at 1 minute (during use of the spirometer), at 2 minutes (at the end of using the spirometer), and at 4 minutes.

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
Vital capacity (the maximal amount of air that can be inhaled, measured in milliliters) during augmented pulse oximetry.
Time Frame: The single maximum value obtained prior to using the spirometer, at 1 minute (during use of the spirometer), at 2 minutes (at the end of using the spirometer), and at 4 minutes.
The single maximum value obtained before, during, or after use of the incentive spirometer.
The single maximum value obtained prior to using the spirometer, at 1 minute (during use of the spirometer), at 2 minutes (at the end of using the spirometer), and at 4 minutes.

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.
Mayo Clinic

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: A. S. Keller, MD, Mayo Clinic

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.

Helpful Links

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

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.
June 1, 2013

Primary Completion (Actual)

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.
November 11, 2024

Study Completion (Actual)

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.
November 11, 2024

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).
June 28, 2013

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 10, 2013

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.
July 12, 2013

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.
March 28, 2025

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.
March 25, 2025

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.
March 1, 2025

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.
  • 12-009527

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

product manufactured in and exported from the U.S.

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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