COPD patients suffering from acute hypercapnic respiratory failure (PaCO2 \> 50 mmHg) due to COPD exacerbation and requiring intermittent NIV treatment can be included in the study provided they do not require immediate intubation.
You may not be if
Patients younger than 18 years old
Inability to give informed consent or denied informed consent
Severe acute respiratory failure requiring immediate intubation defined as respiratory rate \> 40/minute, severe hypoxemia with PaO2/FIO2 ratio \< 150 mmHg despite high FIO2, severe respiratory acidosis with pH\< 7.2, altered mental status)
Very intensive NIV treatment required defined as an impossibility to stop NIV treatment during more than one hour.
Severe hypoxemia requiring more than 4l/minute of conventional oxygenotherapy between NIV treatments
Poor short term prognosis (defined by the clinician in charge as a high risk of death during the next 7 days) or ongoing palliative treatment.
Patients with "Do not resuscitate" order already established
