Guidelines for noninvasive ventilation (NIV) recommend continuous positive airway pressure in patients with thoracic trauma who remain hypoxic . However, no any suggestion was applied for high flow nasal cannula (HFNC). Therefore, Our aim was to determine whether HFNC reduces intubation in severe trauma-related hypoxemia.

This would be a three-center randomized clinical trial of a level I trauma hospital. Inclusion criteria were patients with Arterial oxygen level (Pao2/)fraction of inspired oxygen inspired oxygen fraction(Fio2)<300 while receiving oxygen by high-flow mask within the first 72 h after thoracic trauma. Patients were randomized to remain on high-flow oxygen mask/ noninvasive ventilation or to receive HFNC. The interface was selected based on the associated injuries.

Inclusion Criteria:

Patients who have the following condition within 72 hours of chest trauma despite receiving standard nasal cannula oxygen therapy [≥10 L/min], are eligible for inclusion.

• severe hypoxemic respiratory failure [Arterial partial pressure of oxygen (PaO2)/fraction of inspired oxygen fraction(FiO2) <300 mmHg]
• with a respiratory rate >25 breaths/minute and difficulty breathing, or respiratory distress
• PaCO2 of 45 mmHg or higher (if the patient requires emergency surgery with endotracheal intubation and mechanical ventilation, the time of inclusion will be the start of the post-extubation period. (Note: For patients who receive emergency trauma surgery with endotracheal intubation and mechanical ventilation, the time of inclusion assessment will be 72 hours after extubation.)

Exclusion Criteria:

1. Patients with a Glasgow Coma Scale less than 8 or severe brain injury.
2. Patients with any contraindications to non-invasive ventilation, including acute gastrointestinal bleeding, upper airway obstruction, or hemodynamic instability.
3. Facial trauma involving skull base fractures, facial bone fractures, or orbital floor fractures.
4. Severe injuries involving the nasal sinuses.
5. Patients with cervical spine injuries.
6. Patients with increased intracranial pressure.
7. Patients with facial, nasal, or airway structural abnormalities or surgery that prevents the use of appropriate nasal cannula.
8. Patients after upper airway surgery.
9. Patients who are unable to clearly express their willingness to sign informed consent.