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

This study is enrolling participants by invitation only.
Sponsor:
Information provided by (Responsible Party):
Scott Keller, Mayo Clinic
ClinicalTrials.gov Identifier:
NCT01898637
First received: June 28, 2013
Last updated: July 31, 2014
Last verified: July 2014
  Purpose

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.


Condition Intervention
Pulmonary Embolism
Other: Augmented pulse oximetry using incentive spirometer.
Device: Incentive spirometer.

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Caregiver)
Primary Purpose: Diagnostic
Official Title: A Simple Clinical Tool to Help Diagnose Pulmonary Embolism: Phase 1

Resource links provided by NLM:


Further study details as provided by Mayo Clinic:

Primary Outcome Measures:
  • 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. ] [ Designated as safety issue: No ]
    Trained, blinded Respiratory Therapists 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.


Secondary Outcome Measures:
  • 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 before, during, or after use of the incentive spirometer. ] [ Designated as safety issue: No ]

Estimated Enrollment: 120
Study Start Date: June 2013
Estimated Study Completion Date: June 2015
Estimated Primary Completion Date: June 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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 Name: AirLife Volumetric Incentive Spirometer.
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 Name: AirLife Volumetric Incentive Spirometer.

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.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
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.

  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01898637

Locations
United States, Minnesota
Mayo Clinic
Rochester, Minnesota, United States, 55905
Sponsors and Collaborators
Mayo Clinic
Investigators
Principal Investigator: A. S. Keller, MD Mayo Clinic
  More Information

No publications provided

Responsible Party: Scott Keller, PI, Mayo Clinic
ClinicalTrials.gov Identifier: NCT01898637     History of Changes
Other Study ID Numbers: 12-009527
Study First Received: June 28, 2013
Last Updated: July 31, 2014
Health Authority: United States: Institutional Review Board

Keywords provided by Mayo Clinic:
pulmonary embolism
pulse oximetry
change in oxygen saturation
hypoxemia
emergency department
deep inspiration
vital capacity
clinical diagnosis

Additional relevant MeSH terms:
Embolism
Pulmonary Embolism
Embolism and Thrombosis
Vascular Diseases
Cardiovascular Diseases
Lung Diseases
Respiratory Tract Diseases

ClinicalTrials.gov processed this record on September 16, 2014