Supplemental Oxygen in Pulmonary Embolism (SO-PE) (SO-PE)

A study of how supplemental oxygen helps patients with acute pulmonary embolism (PE).

Hypothesis: Oxygen affects right ventricular dysfunction (RVD) in patients with acute pulmonary embolism (PE) primarily by relieving hypoxic pulmonary vasoconstriction and reducing pulmonary pressure (PA) pressure, and that this process is metabolically driven.

Study Overview

• Status: Recruiting
• Conditions: Venous Thromboembolism; Pulmonary Embolism; Metabolomics; Oxygen Inhalation Therapy
• Intervention / Treatment: Drug: Oxygen Therapy; Device: Non-rebreather mask

Detailed Description

In the Emergency Department (ED), investigators will perform a randomized, crossover trial of adult patients with acute PE.

Study subjects will be randomized to one of two interventions (supplemental oxygen delivered by facemask) vs. room air. Therapy will be alternated at t=30, t=60, t=90 minutes, and then maintained for 180 minutes.

After each treatment change, and at 180 minutes, investigators will: 1) perform echocardiograms to determine how oxygen affects right ventricular dysfunction (RVD) and, 2) draw blood for metabolomic analyses to determine the metabolic pathways that change in response to oxygen therapy.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Early Phase 1

Contacts and Locations

• Study Contact: Name: Christopher Kabrhel, MD, MPH; Phone Number: 617-726-7622; Email: ckabhrel@mgb.org
• Study Contact Backup: Name: Blair Alden Parry, CCRC, BA; Phone Number: 617-724-4758; Email: bparry@mgh.harvard.edu

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Recruiting
      • Massachusetts General Hospital
      • Principal Investigator: Christopher Kabrhel, MD, MPH
      • Contact: Blair Alden Parry, CCRC, BA; Phone Number: 617-724-4758; Email: bparry@mgh.harvard.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adults ≥18 years old
• Confirmed Pulmonary Embolism (PE) on imaging <24 hours prior to enrollment
• New symptom onset and / or worsening symptoms <72 hours
• Confirmation of right ventricular dysfunction (RVD) by clinician
• Oxygen saturation ≥90% while breathing room air

Exclusion Criteria:

• Hemodynamic instability
• Use of vasopressors or mechanical circulatory support
• Planned use of thrombolytics or plan for embolectomy
• Oxygen saturation <90% while breathing room air
• New onset arrhythmia
• History of pulmonary hypertension, severe chronic obstructive pulmonary disease (COPD) requiring home oxygen or chronic steroid use, hypoventilation syndrome requiring continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP), or congestive heart failure (CHF) with LV ejection fraction < 40% or chronic oxygen therapy
• Known pregnancy
• Vasodilator medication used in the past 24 hours
• Symptom onset ≥72 hours
• Inability to wear a face mask
• Inability to obtain adequate baseline echocardiogram

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Supplemental oxygen delivered by facemask; Patients with acute PE will be randomized to breathing supplemental oxygen by non-rebreather face mask first. Subjects will alternate treatments (supplemental oxygen or room air) every 30 minutes for 90 minutes (e.g. T=30, T=60, T=90) and then will maintain their treatment (oxygen or room air) for a total of 180 minutes.	Drug: Oxygen Therapy; Study subjects will be asked to breathe supplemental, or extra, oxygen during several time periods.; Device: Non-rebreather mask; Non-rebreather mask is a non-invasive oxygen supplementation device that is used to provide continuous oxygen flow, typically in a hospital setting.; Other Names: NRM (Non-rebreather mask)
Active Comparator: Room air delivered by facemask; Patients with acute PE will be randomized to breathing room air by non-rebreather face mask first. Subjects will alternate treatments (supplemental oxygen or room air) every 30 minutes for 90 minutes (e.g. T=30, T=60, T=90) and then will maintain their treatment (oxygen or room air) for a total of 180 minutes.	Device: Non-rebreather mask; Non-rebreather mask is a non-invasive oxygen supplementation device that is used to provide continuous oxygen flow, typically in a hospital setting.; Other Names: NRM (Non-rebreather mask)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pulmonary artery systolic pressure (PASP)	PASP is measured on bedside echocardiogram	30 minutes after study treatment (supplemental oxygen) or placebo (room air)
Pulmonary artery systolic pressure (PASP)	PASP is measured on bedside echocardiogram	60 minutes after study treatment (supplemental oxygen) or placebo (room air)
Pulmonary artery systolic pressure (PASP)	PASP is measured on bedside echocardiogram	90 minutes after study treatment (supplemental oxygen) or placebo (room air)
Pulmonary artery systolic pressure (PASP)	PASP is measured on bedside echocardiogram	180 minutes after study treatment (supplemental oxygen) or placebo (room air)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Right ventricular to left ventricular ratio (RV/LV)	RV/LV ratio is measured on bedside echocardiogram	30 minutes after study treatment (supplemental oxygen) or placebo (room air)
Right ventricular to left ventricular ratio (RV/LV)	RV/LV ratio is measured on bedside echocardiogram	60 minutes after study treatment (supplemental oxygen) or placebo (room air)
Right ventricular to left ventricular ratio (RV/LV)	RV/LV ratio is measured on bedside echocardiogram	90 minutes after study treatment (supplemental oxygen) or placebo (room air)
Right ventricular to left ventricular ratio (RV/LV)	RV/LV ratio is measured on bedside echocardiogram	180 minutes after study treatment (supplemental oxygen) or placebo (room air)
Concentrations of circulating metabolites and metabolic profiles measured by high-throughput metabolomic assays	Investigators will perform high-throughput metabolomics to identify changes in circulating blood metabolites associated with supplemental oxygen use in patients with acute PE.	30 minutes after study treatment (supplemental oxygen) or placebo (room air)
Concentrations of circulating metabolites and metabolic profiles measured by high-throughput metabolomic assays	Investigators will perform high-throughput metabolomics to identify changes in circulating blood metabolites associated with supplemental oxygen use in patients with acute PE.	60 minutes after study treatment (supplemental oxygen) or placebo (room air)
Concentrations of circulating metabolites and metabolic profiles measured by high-throughput metabolomic assays	Investigators will perform high-throughput metabolomics to identify changes in circulating blood metabolites associated with supplemental oxygen use in patients with acute PE.	90 minutes after study treatment (supplemental oxygen) or placebo (room air)
Concentrations of circulating metabolites and metabolic profiles measured by high-throughput metabolomic assays	Investigators will perform high-throughput metabolomics to identify changes in circulating blood metabolites associated with supplemental oxygen use in patients with acute PE.	180 minutes after study treatment (supplemental oxygen) or placebo (room air)

Collaborators and Investigators

• Sponsor: Massachusetts General Hospital
• Collaborators: National Heart, Lung, and Blood Institute (NHLBI); Aarhus University Hospital
• Investigators: Principal Investigator: Christopher Kabrhel, MD, MPH, Massachusetts General Hospital

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2023
• Primary Completion (Estimated): June 30, 2027
• Study Completion (Estimated): June 30, 2027

Study Registration Dates

• First Submitted: May 4, 2023
• First Submitted That Met QC Criteria: May 26, 2023
• First Posted (Actual): June 7, 2023

Study Record Updates

• Last Update Posted (Actual): June 15, 2025
• Last Update Submitted That Met QC Criteria: June 12, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: PE; Pulmonary Embolism; Right ventricular dysfunction
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Respiratory Tract Diseases; Lung Diseases; Embolism and Thrombosis; Pulmonary Embolism; Embolism; Thromboembolism; Venous Thromboembolism
• Other Study ID Numbers: 2023P000252

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

IPD Plan Description

There is no plan to make individual participant data (IPD) available to other researchers.

The results of this study will be published in scientific journals and presented at national/international scientific meetings.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No