The objective of this randomized cross-over trial is to assess the physiological effects of three different facemasks for noninvasive ventilation (Nivairo, Visairo, Optiniv) in patients with acute hypercapnic respiratory failure
PaCO2 ≥ 45 mmHg;
Arterial pH < 7.35;
Signed written informed consent
Respiratory rate < 12 bpm;
Immediate need for intubation;
Haemodynamic instability (Systolic blood pressure <90 mmHg or mean arterial pressure <65 mmHg) and/or lactic acidosis (lactate >5 mmol/L) and/or clinically diagnosed shock;
Metabolic Acidosis;