to the editor: We read the article by Biselli et al. (1) carefully and congratulate the authors on their original research about the use of high-flow nasal cannula (HFNC) in patients with chronic obstructive pulmonary disease (COPD) during sleep.
HFNC oxygen is an emerging technique in patients with respiratory failure (1). HFNC provides a heated and humidified air at flows up to 60 l/min and it has some physiological advantages compared with other standard oxygen therapies, so its use is growing worldwide (2, 3).
The number of studies related to the use of HFNC in stable COPD patients is growing, with interesting results, particularly, with the reduction in Pco2 (4). Until now, noninvasive ventilation (NIV) remains the first choice, for example, in acute exacerbations of COPD patients; however, regarding recent studies, HFNC appears to be an alternative for these patients because of its effect in reducing anatomical dead space, PEEP, constant and good humidification (3). The ventilation paradigm will certainly change in the future.
Regarding the study of Biselli et al. (1), there are some practical aspects that may limit proper practical extrapolations that need to be considered.
First, this study enrolled a small number of patients, with only four COPD patients with gastroesophageal sphincter, which makes it difficult to draw strong conclusions about the results presented. This is an important mechanism that may influence results.
Second, it would be interesting to evaluate partial pressure of CO2 with higher flows. This may add a more appropriate interpretation for different COPD severities and a more defined criteria.
In addition, subgroup analysis of patients with FEV1 less than 50%, whose ventilatory demand is higher, may obtain interesting results of Pco2, tidal volumes, and minute ventilation.
In short, HFNC is the therapy that has changed the most in the management of patients with acute respiratory failure in the last few years, with many indications that promise to revolutionize the ventilatory strategy in the next years.
No conflicts of interest, financial or otherwise, are declared by the authors.
P.S.S., C.C., and A.M.E. conceived and designed research.
- Copyright © 2017 the American Physiological Society