Chest trauma is common in traumatology. Its management is based on ventilatory therapies, among which non-invasive ventilation (NIV) is commonly used. Some studies have shown the benefit of this therapy in hypoxemic patients, avoiding intubation, reducing length of stay and healthcare costs, and even reducing mortality. However, these studies are old and underpowered. High flow oxygen therapy (HFO), which is frequently used in everyday practice, has only one study in chest trauma.

There is still a lack of data to really understand the effects of these techniques on the injured lung after trauma. Therefore, the investigators want to do a NIV or HFO session and directly assess the effects on participants' lungs by doing a CT at the end of the session.

This is a procedure carried out within five days of the initial trauma and consists of either a 10-minute session of non-invasive ventilation or a 10-minute session of high-flow oxygen therapy, depending on which arm the participant is allocated to.

Two chest CTs will be performed: the first as part of usual care before the non-invasive ventilation session or high flow oxygen therapy session, and the second immediately after the 10-minute session.

The investigator's objective is to demonstrate an improvement in lung recruitment with NIV or HFO using CT imaging.

Inclusion Criteria:

• Age > 18 years old
• Chest trauma < 5 days
• At least 3 ribs fracture on initial CT-scan
• Need of oxygen moderated to maintain monitoring oxygen saturation Sp02 > 92% or partial pressure of arterial oxygen Pa02/ Fraction of inspired oxygen FiO2 > 200
• Intensive Care Unit admission
• Need a chest CT control during the five first days after the trauma

Exclusion Criteria:

• Patient intubated or with respiratory failure : measured or estimated Pa02/FiO2 < 200 or indication for intubation (several with respiratory rate > 35/min, abundant tracheal secretions, significant increase in work of accessory respiratory muscles on inspiration, signs of respiratory exhaustion on arterial blood gas with The potential of Hydrogen pH < 7,3 or PaCO2 > 50 mmHg, severe hypoxemia with PaO2/FiO2 ratio < 100 or desaturation < 88% for more than 5 minutes)

  • Inability to maintain 10 seconds of apnoea required for scan acquisition
  • Patient treated with ventilatory support by NIV or HFO in the 12 hours prior the investigation
  • Uncontrolled circulatory failure with need for introduction of Noradrenaline > 0,15 ug/kg/min
  • Uncontrolled neurological failure with Glasgow Coma Scale (CGS < 15
  • Unstable facial trauma or with pneumocephalus or basilar skull trauma
  • Large, undrained pneumothorax with lateral separation at the level of the hilum > 2 cm and extensive throughout the axillary line
  • Patients with identified cognitive impairment
  • Persons deprived of liberty, persons under protective measures
  • Persons not affiliated to a social security insurance
  • Current pregnancy or breastfeeding
  • Refusal to participate in the study