recruitment difficulties

Pulmonary embolism is a frequent and recurrent pathology, especially in the elderly. It is often preventable, with high mortality and morbidity, making it a major public health issue. The clinical presentation of pulmonary embolism is non-specific and very highly variable, ranging from asymptomatic thrombus diagnosed incidentally to sudden death. The current diagnosis of pulmonary embolism is based on several diagnostic techniques, mainly non-invasive, which should be used sequentially.

We propose to sample the volatile organic compounds using a device that allows them to be trapped on polymer cartridges. Sampling will be performed under monitoring of respiratory pressure and a capnograph to collect alveolar and upper respiratory tract air separately without contamination of the oral cavity or sinuses.

This exploratory metabolic analysis will be non-targeted (analysis of all molecules detectable without a priori).

The main objective of the study is to identify specific metabolic profiles to predict the results of ventilation-perfusion pulmonary tomoscintigraphy in subjects undergoing this examination for suspected acute pulmonary embolism.

Secondary purposes :

• To identify metabolic profiles to be used to predict, in combination with clinical probability scores, the results of ventilation-perfusion pulmonary tomoscintigraphy in subjects undergoing this examination for suspected acute pulmonary embolism.;
• To correlate metabolic profiles with the topography of embolized lung territories

Inclusion Criteria:

• Male or female, at least 18 years old
• Patients with clinical suspected pulmonary embolism
• Patient willing and able to provide informed consent

Exclusion Criteria:

• Contraindications to pulmonary ventilator-perfusion tomoscintigraphy
• All types of thrombolytic or anticoagulant treatment
• Diagnosis of pulmonary embolism established prior to inclusion in the study
• Massive pulmonary embolism (systolic pressure < 90 mm Hg)
• Pregnancy
• Breastfeeding

Consecutive patients presenting to the Nuclear Medicine Department of our hospital for a pulmonary ventilation-perfusion tomoscintigraphy will be proposed to participate in the study