Influence of FreeO2 on Percentage of Time Within Oxygen Saturation Target Using Noninvasive Ventilation (NIV) and Continuous Positive Airway Pressure (CPAP) for Patients Admitted for AECOPD or Bariatric Surgery

During this period the patients will breath spontaneously oxygen titrated using the FreeO2 device with a SpO2 target set at 90%. The period duration is 30 minutes.

During this period the patients will receive NIV using FreeO2 device for oxygen titration with a SpO2 target set at 90%. Initially, the inspiratory pressure will be set to obtain a tidal volume between 6 to 8 mL/Kg of predictive body weight and positive end-expiratory end pressure (PEEP) at 5 centimeters of water (cmH2O). After NIV initiation, the parameters can be adjusted to improve patient comfort. The period duration is 30 minutes.

During this period the patients will receive NHFOT using the FreeO2 device for oxygen titration with a SpO2 target set at 90%. The high flow device will be set at 30 lpm.The period duration is 30 minutes.

During this period, the patients will have their own CPAP with oxygen adjusted by hospital staff according to hospital protocol. The period duration is 15 minutes.

During this period, the patients will have their own CPAP with oxygen adjusted using the FreeO2 device. SpO2 target will be set at 90% The period duration is 60 minutes.