Early Non-invasive Ventilation and High-flow Nasal Oxygen Therapy for Preventing Delayed Respiratory Failure in Hypoxemic Blunt Chest Trauma Patients

In blunt chest trauma patients without immediate life‐threatening conditions, delayed respiratory failure and need for mechanical ventilation may still occur in 12 to 40% of patients, depending on the severity of the trauma, the preexisting conditions and the intensity of initial management. In this context, non‐invasive ventilation (NIV) is recommended in hypoxemic chest trauma patients, defined as a PaO2/FiO2 ratio < 200 mmHg. However, there is a large heterogeneity among studies regarding the severity of injuries, the degree of hypoxemia and the timing of enrollment. The interest of a preventive strategy during the early phase of blunt chest trauma, before the occurrence of respiratory distress or severe hypoxemia, is not formally established in the literature. Moreover, high‐flow nasal oxygen therapy (HFNC‐O2) appears to be a reliable and better tolerated alternative to conventional oxygen therapy (COT), associated with a significant reduction in intubation rate in hypoxemic patients. Two NIV strategies are compared: 1. In the experimental strategy, NIV is performed after inclusion in patients with moderate hypoxemia, defined by a PaO2/FiO2 ratio < 300 mmHg. The minimally required duration of NIV was 4 hours per day for at least 2 calendar days. 2. In the control group, patients receive oxygen from nasal cannula or high concentration oxygen mask according to the FiO2 needed to achieve SpO2 > 92%. NIV is initiated only in patients having PaO2/FiO2 ratio < 200 mmHg under COT. Investigators hypothesized that an early strategy associating HFNC‐O2 and preventive NIV in hypoxemic blunt chest trauma patients may reduce the need for mechanical ventilation compared to the recommended strategy associating COT and late NIV.