Optimisation of High Flow Oxygen Therapy Settings During Hypoxaemic Respiratory Distress Based on Non-contact Measurement of Lung Volumes by Depth Camera

High-flow oxygen therapy (HFO) is a common technique for the management of patient with hypoxemic respiratory distress in intensive care.The variations in lung volumes induced by the HFO in patients is unknown in clinical routine, in the absence of the availability of a effective measurement technique.

The investigators research team validated a new non-invasive, non-contact technique for measuring lung volumes using depth camera. Using a stereoscopic camera, the patient's chest and abdomen are recognized by a artificial intelligence algorithms. The structures of interest of the chest and the abdomen are the identified and the variation in depth of these points in space allows both the integration of lung volume through automatic calibration procedures, the measurement of respiratory rate and comparaison of movement symetries.

Inclusion criteria

• Patients with hypoxemic respiratory distress define by the following 4 criteria:
• Respiratory rate ≥ 25 breaths per minutes
• A ratio of the partial pressure of arterial oxygen (PaO2) to the FiO2 ≤ 300 mmHg while the patient is breathing oxygen at a flow rate of 10 liters per minutes or more
• A partial pressure of arterial carbon dioxide (PaCO2) not higher than 45 mmHg
• An absence of clinical history of underlying chronic respiratory failure

Exclusion criteria

• A do-not-intubate order
• Pregnant or lactating woman
• Cardiogenic pulmonary edema
• Exacerbation of asthma
• Hemodynamic instability with use of vasopressor at significant dose (norepinephrine > 0.5 mg/h)
• A Glasgow Coma Scale of 12 points of less
• Contraindications to non-invasive ventilation
• Urgent need for endotracheal intubation
• High flow oxygen therapy started within 48 hours before inclusion
• Patient under legal protection or deprived of liberty