The use of high-flow nasal oxygen in COPD patients

Abstract

Pedro Silva Santos,1 Antonio M Esquinas21Pulmonology Unit, Centro Hospitalar e Universitário de Coimbra – Hospitais da Universidade de Coimbra, Coimbra, Portugal; 2Internsive Care Unit, Hospital Morales Meseguer, Múrcia, SpainHigh-flow nasal cannula (HFNC) oxygen therapy is an innovative and useful mode for the treatment of patients with respiratory failure.1–3 It delivers heated and humidified air providing higher and more expected gas flow rates and fraction inspired oxygen (FiO2) than traditional oxygen therapy.2     We read the article by Bräunlich et al1 carefully and congratulate the authors on their study about the use of nasal high-flow therapy in COPD patients. There are, however, some limitations to the study that need to be considered.    First, this study has a small number of patients, particularly in groups A and B, which in our opinion will affect the comparison of data with the group C that contains a greater variety of patients with more severe outcomes, including forced expiratory volume in 1 second and forced vital capacity. Second, as a study on mean airway pressure, it would be interesting to evaluate partial pressure of CO2 with higher flows.    Third, one of the aims of this study was to characterize changes in hypercapnia, so it is not correct to include nonhypercapnic patients. Fourth, it would be interesting to know the FiO2 that was given and whether the patients had domiciliary oxygen or noninvasive ventilation, as most of them are hypercapnic patients. Finally, regarding comfort and dyspnea scale, HFNC showed better results, which may increase its use when intolerant to noninvasive ventilation.    In short, HFNC is an interesting mode for the future treatment of COPD patients with respiratory failure, which may lead to larger and randomized trials to confirm this indication.View original paper by Bräunlich et al.