We would like to thank Dr. Úbeda et al., for being interested on our manuscript.1 All patients requiring non-invasive mechanical ventilation and having in place one or more naso- or oro-enteric tube(s) were consecutively included over a period of 16-month, unless contraindications for non-invasive ventilation were present.1 A total of 1258 patients required invasive mechanical ventilation during the study period, while 516 were subjected for at least one run of NIMV. From these last patients, 196 met the inclusion criteria and consequently, they were subjected to the study intervention consisting of conventional NIVM (C-NIMV) run for 60min followed by other 60min of NIMV using the tube adaptor (TA-NIMV) (or in the inverse order), maintaining a “washout period” of at least 4h between runs.1 No patients fulfilling the inclusion criteria were excluded, so our results are well adjusted to the reality. Order to start with conventional or tube-adapter NIVM was alternatively assigned in a 1:1 relationship according to the inclusion sequence until the sample was completed. Although sequential assignments might introduce bias, NIMV was provided by all the group of physiotherapists according to patient requirements, thus preventing researchers from choosing an order favoring one or other intervention. In addition, such sequential change in the order to start with C- or TA-NIMV should prevent that one intervention was selected as more comfortable.

Dr. Úbeda et al. are also concerned for the problems derived from using a visual analog scale to evaluate the comfort provided by the tube-adapter device during NIMV. It is highly possible that measurements provided by this type of scales are skewed toward the neutral values. Nevertheless, the significant difference observed between C- and TA-NIVM reinforces the message about the ability of the tube adapter to improve the patient's comfort during a NIMV run, since the inherent characteristics of visual analog scales could even underestimate its potential role.

Other studies evaluating comfort during NIMV included a lower number of patients, with not clues about sample size calculation, which suggest that convenience samples were used.2,3 Conversely, sample size in our study was calculated on the basis of air leakage rates which retrieved a higher number of patients to be included than if calculation had been based on comfort estimates and of course, far higher than previously used convenience sample sizes. Comfort was reported from 99 patients able to clearly understand the visual analog scale, a number well above that necessary to demonstrate a significant difference regarding this endpoint, with a power of 80%.

It is difficult for us to claim that improvement in some respiratory and hemodynamic parameters was the result of TA-NIMV alone or the sum of both therapies. Nevertheless, tidal volumes, respiratory rates and oxygen pulse saturation were obtained during C- or TA-NIMV runs maintaining a “washout period” of at least 4h between them. As previously mentioned, starting with C-NIVM followed by starting with TA-NIVM in the next patient and so sequentially, should prevent favoring one intervention over the other. Thus, better respiratory parameters during the use of the tube adapter keep the logic and support the hypothesis about less air leakages with better adaptation to NIMV and improvement in respiratory mechanics and oxygenation.

Finally, we agree with Dr. Úbeda about heterogeneity could make patients non-comparable. Nevertheless, we think that our study provides a notion on the feasibility and possible effectiveness of this new tube adaptor to prevent air leakages to improve comfort during conventional NIMV. Finally, whether using this new tube adapter during NIMV in patients having in place one or more naso- or oro-enteric tube(s) could improve clinical outcomes is a question yet unanswered.