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


  • Study type

  • Study IDs

  • Describes the nature of a clinical study. Types include:

    • Observational study — observes people and measures outcomes without affecting results.
    • Interventional study (clinical trial) — studies new tests, treatments, drugs, surgical procedures or devices.
    • Medical records research — uses historical information collected from medical records of large groups of people to study how diseases progress and which treatments and surgeries work best.
  • Site IRB
    • Rochester, Minnesota: 12-009527
    NCT ID: NCT01898637
    Sponsor Protocol Number: 12-009527

About this study

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 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.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. If you need assistance understanding the eligibility criteria, please contact the study team.

See eligibility criteria

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.

Participating Mayo Clinic locations

Study statuses change often. Please contact us for help.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

A Keller, M.D.

Closed-enrolling by invitation

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Contact information:

Donna Lawson




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