Overview
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.
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.
Eligibility
Inclusion Criteria:
- Adults ≥18 years old
- Confirmed Pulmonary Embolism (PE) on computed tomography pulmonary angiography (CTPA) performed <24 hours prior to enrollment
- Symptom duration <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 at any time in the Emergency Department (ED)
- New onset arrhythmia
- History of pulmonary hypertension, chronic obstructive pulmonary disease (COPD), hypoventilation syndrome, or congestive heart failure (CHF) with left ventricular ejection fraction <40%
- Known pregnancy
- Use of chronic oxygen therapy at baseline
- Vasodilator medication used in the past 24 hours
- Symptom onset ≥72 hours
- Inability to wear a face mask
- Technically inadequate baseline echocardiogram
- Temperature >39° C
- Positive test for Covid-19 or influenza within the previous 10 days