To the Editor Esianor and coworkers recently studied the association between endotracheal tube (ETT) size and outcomes in critically ill patients.1 We commend the authors for investigating this relevant topic; however, we would like to raise some issues.

First, although the authors claim that their definition of the ideal ETT size draws from an established nomogram, there are numerous discrepancies between their definition and the nomogram.2 With an arbitrary definition of what an inappropriately sized ETT is, it is difficult to draw conclusions on its relationship with outcomes.