The authors reply
First, as clearly stated in our article, we did not want to demonstrate that noninvasive ventilation (NIV) is equally effective regardless of the setting (ICU vs ordinary ward). This would require a randomized controlled trial, whose generalizability would be very questionable. More simply, we operate in a teaching hospital including all specialties and with a limited number of ICU beds, as many other hospitals worldwide. Recent literature strongly demonstrated that NIV has a marked beneficial effect on survival in patients with acute respiratory failure (ARF), above all when applied early (3, 4). Denying an early application of NIV when indicated can be lethal, so this decision must be justified: in our opinion, the lack of an available ICU bed should not be considered a sufficient reason (5). NIV use outside the ICU seems safer and easier than it was feared in the past; in our article recently published in this journal (2), we intended to evaluate if the long-term outcomes of patients treated with NIV outside the ICU was satisfying and in the same range of patients treated with the gold standard (i.e., ICU). Like ultrasonography performed by non-radiologists, the spread of NIV in ordinary wards requires training, monitoring, and carefulness but can offer many advantages.
Second, our pragmatic study describes real-world practice of a NIV service managed outside the ICU by a busy medical emergency team. We agree with Chertoff (1) that arterial blood gas (ABG) values would have helped in better defining the etiology of ARFs. Unfortunately, in many cases, we were unable to ascertain the oxygen fraction the patient was breathing when basal ABG was performed; furthermore, in urgent cases, ABG was often performed “after” starting NIV. Given the unreliability of the data, we did not include ABG values among the reported data and considered sufficiently informative the chosen device. In our local protocol, continuous positive airway pressure (CPAP) is preferred in hypoxemic patients, whereas noninvasive positive pressure ventilation is applied when hypercapnia prevails. As we reported in the article, CPAP was applied in 54% of cases. Accordingly, we compared our findings to the outcomes of other studies on the basis of the cause of ARF, and not of the type (hypoxemic or hypercapnic) of ARF.
Finally, we fully agree that high-flow nasal oxygen (HFNO) is a simple, safe, and promising technique in hypoxemic patients. However, the most recent meta-analysis failed to find any benefit compared to standard oxygen therapy or NIV (6). More research is still required to define the role of HFNO in adult patients—and so far we are unaware of studies performed with HFNO in ordinary wards.
The authors have disclosed that they do not have any potential conflicts of interest.