Kim ES, et al. - In this current study, researchers assessed the efficacy of high-flow nasal cannula (HFNC) oxygen therapy for acute respiratory failure with hypercapnia. Significant reduction in partial pressure of arterial carbon dioxide (PaCO₂) was noted in patients with acute respiratory failure with hypercapnia who were treated with HFNC oxygen therapy with sufficient fraction of inspired oxygen (FiO₂) to maintain a normal partial pressure of arterial oxygen (PaO₂).