We share the concerns expressed by Quintero et al.1 on comfort and air leakage during non-invasive mechanical ventilation (NIMV) with the need of using oral or naso-oral probes. The authors designed their device aiming to decrease air leaks to improve patient comfort, which is related to success of NIMV.

After reading the article, we found several discussion points.

First. We think that the selection of patients included as their own controls is a success.

Second. Quintero et al.1 included 196 patients but there is no flowchart explaining how many patients met the inclusion criteria and how many were excluded and the reasons.

Third. To asses comfort, they used a qualitative ordinal scale with only 5 options to choose from. When using that type of scales, there could be a tendency of regression toward the central value, so that measurement bias could appear.

Fourth. It is not explained if patients begin with NIVM using the adapter or the conventional tube. If a patient first receives the most uncomfortable one, when it is changed to the comfortable one, his perception of comfortability may be higher. We believe that this matter should have been addressed.

Fifth. The authors estimated a sample size of 191 patients and they included 196 patients in the study but comfort was evaluated only in 99 patients with Glasgow Coma Scale of 15, so sample size was not reached for one of the outcome of interest.

Sixth. Respiratory and hemodynamic parameters during NIMV, such as inspiratory and expiratory tidal volumes, oxygen saturation and respiratory rate, were better in the NIMV with tube adaptor group, but it is difficult to know if it was the result of TA-NIMV alone or the sum of both therapies.

Seventh. Therapy was performed according to individual needs, so patients could have received different therapies and that heterogeneity could make patients non-comparable.

Quintero et al.1 concluded that the use of their tube adaptor to adjust NIMV mask interfaces in patients in whom oro or naso-enteral tubes were in place, significantly reduced air leaks and improved subjective comfort perceived by the patient during NIMV support.

As there has been no important changes in recommendations published within the past 15 years regarding the use of NIMV for various forms of respiratory failure 2, we believe that proposals like Quintero's gastric feeding tube adaptor may improve the assistance of patients with respiratory failure during NIMV, even though further studies should be performed to correct biases.