Dear editors:

We are pleased to present a critical letter on the article “Low-cost devices to decrease aerosol effect during upper gastrointestinal endoscopy in COVID-19”. This describes an innovative method for performing this type of test using a conventional mask and reducing aerosol transmission in patients¹.

In view of the above, we believe that the article should inform how this procedure is carried out in a more complete manner. Points such as the procedure’s name should be specified in times of coronavirus disease since it is currently known as an aerosol-generating procedure (AGP), due to the possibility of regurgitation and cough during digestive endoscopy in a so-called high-risk area².

As it is not carried out on all patients, another crucial issue is the reason why this practice should be carried out: it should be limited to emergency cases that cannot be postponed. Similarly, each patient must have medical records, and screenings should be carried out; also, it is essential to take into account whether these patients were exposed to an infected person, their signs and symptoms, their vital functions, travel history, among other things. In addition, the environment where it must be carried out should be considered. These specific rooms are, for example; a negative pressure room or biosafety environment level 3 (NBS3)^2-3.

It is also necessary to specify the personal protective equipment (PPE) that the doctor must use, in cases where the patient is infected with coronavirus disease 2019 (COVID-19) or not, which varies in the use of a conventional mask when the patient is not suspicious of contagion, to a KN95 mask when the patient is suspicious of contagion³.

Even the Inter American Society of Digestive Endoscopy (SIED) considers this procedure to be so high risk that , it proposes sedating the patient to perform the scan and to reduce the risk of exposure to the virus. Therefore, the population should not be encouraged to carry out this procedure in order to reduce the risk of contagion⁴.