Supplemental oxygen for pulmonary embolism (SO-PE): study protocol for a mechanistic, randomised, blinded, cross-over...

Area of Science:

• Cardiology
• Pulmonology
• Critical Care Medicine

Background:

• Acute pulmonary embolism (PE) can cause right ventricular (RV) dysfunction due to increased pulmonary artery (PA) pressure.
• Oxygen is a pulmonary vasodilator, but its mechanisms in human PE are not fully understood.
• Preclinical models suggest supplemental oxygen improves RV function in PE.

Purpose of the Study:

• To investigate the mechanisms by which supplemental oxygen affects hemodynamics and RV function in acute PE patients.
• To determine the impact of supplemental oxygen on pulmonary artery pressures and RV strain in non-hypoxemic PE patients.

Main Methods:

• Randomized, double-blind, cross-over trial (SO-PE study) including 80 adult patients with acute PE and RV dysfunction.
• Patients alternate between supplemental oxygen (60% FiO2) and room air (21% FiO2) for 180 minutes.
• Primary outcome: difference in pulmonary artery systolic pressure; secondary outcomes: echocardiographic measures, metabolomics, vital signs, and dyspnea scores.

Main Results:

• The primary outcome is the change in pulmonary artery systolic pressure.
• Secondary outcomes include changes in echocardiographic parameters, metabolomic profiles, vital signs, and patient-reported dyspnea scores.
• Statistical analysis includes paired t-tests, Wilcoxon signed-rank tests, and multivariable mixed effects logistic regression with FDR correction.

Conclusions:

• The study aims to elucidate the physiological effects of supplemental oxygen in acute PE.
• Findings will inform clinical management strategies for PE patients with RV dysfunction.
• Understanding these mechanisms can lead to improved patient outcomes and reduced mortality.