The treatment of respiratory failure due to pneumonia with NIV may also lead to greater mortality than other modes of non‐invasive oxygen supplementation such as HFNC.31 Interestingly, only one study has considered the use of NIV in CAP and AHRF in patients with a preexisting CLD.119 Fifty‐five patients were randomized to NIV or standard treatment. Subgroup analysis showed that patients randomized to NIV had a reduced need for intubation and a better 2‐month survival. However, this was not confirmed among those patients with ‘pure hypoxia’, suggesting that in AHRF associated with CAP, NIV may be of some benefit.Many patients with cystic fibrosis (CF) develop respiratory failure from progressive airway obstruction and bronchiectasis and when the disease becomes more severe, hypercapnia may ensue.126 At this stage, NIV may focus on alleviating both the symptomatic and physiological effects of respiratory failure.1, 127 Patients with CF or bronchiectasis may suffer AHRF during an exacerbation of moderate to severe disease, or indeed without any identified specific acute cause. In this population, NIV ameliorates dyspnoea and avoids ETI and its complications.128-131 Moreover NIV could sustain life until more definitive life prolonging treatment could be offered; NIV as a ‘bridge’ to transplant has become routine at centres capable of performing lung transplant for CF.129, 131-133 However, to date, only modest evidence supports the use of NIV in patients with CF, and there were no long‐term data on its safety or efficacy.