HFNC vs. NIV in Acute COPD Exacerbations

The NIV group received bilevel-positive airway pressure. During NIV, the tidal volume was set to 6-8 mL/kg, positive expiratory end pressure (PEEP) to 3-5 cm H2O, and pressure support ventilation (PSV) to 8-12 cm H2O by a clinician with 8 years of experience. To reduce potential bias, the clinician was blinded to the null hypothesis.

The HFNC-30 group received HFNC therapy at flow rates of 30 L/min. During HFNC, the humidifier was set to an open position, the heated air temperature was maintained at 37°C, and the FiO2 was adjusted to maintain an oxygen saturation (SpO2) measured via pulse oximetry of at least 92%.

The HFNC-50 group received HFNC therapy at flow rates of 50 L/min. During HFNC, the humidifier was set to an open position, the heated air temperature was maintained at 37°C, and the FiO2 was adjusted to maintain an oxygen saturation (SpO2) measured via pulse oximetry of at least 92%.