Last Word on Viewpoint: Using the same cut-off for sulfur hexafluoride and nitrogen multiple-breath washout may not be appropriate

to the editor: We agree with all important points of the four commentaries (see Ref. [6][1]): a ) Both SF6- and N2-multiple-breath washout (MBW) seem to be useful in detecting ventilation inhomogeneity in patients with cystic fibrosis (CF) and primary ciliary dyskinesia (PCD). b ) There are