Extra oxygen for people with acute pulmonary embolism of intermediate risk

Who can take part

• Pulmonary embolism confirmed by multidetector computed tomographic pulmonary angiography
• Right ventricular enlargement confirmed by computed tomography (transverse view) or echocardiography (apical or subcostal four chamber) where the right ventricle/left ventricle ratio is >1.0

Who cannot take part

• Participating in any other investigational drug or device study
• Use of chronic oxygen therapy
• Contraindication to anticoagulant therapy according to the physician judgement
• Age less than 18 years
• Life expectancy <90 days at the discretion of the enrolling clinician
• Oxygen saturation of less than 90% on pulse oximetry at the time of diagnosis
• Technically inadequate basal computed tomography or echocardiography that prohibits the measurement of the right and left ventricle dimensions
• Known hypercapnia (pCO2 >50 mmHg on arterial blood gases) at the time of diagnosis
• Time elapsed since index diagnosis of pulmonary embolism symptom >10 days
• Hemodynamic collapse at the time of PE diagnosis, defined as: need for cardiopulmonary resuscitation; or systolic blood pressure <90 mmHg for at least 15 min, or drop of systolic blood pressure by at least 40 mmHg for at least 15 min with signs of end organ hypoperfusion (cold extremities or low urinary output <30 mL/h or mental confusion); or need for catecholamine administration to maintain adequate organ perfusion and a systolic blood pressure of >90 mmHg
• Inability to use mask or nasal prongs