Why it happens: the right main bronchus is more vertical and wider, so an overly advanced tube commonly enters it. Management is to withdraw the tube slightly, reassess bilateral air entry, and confirm its position on chest radiograph. The tube tip should normally lie a few centimeters above the carina. This is also why anesthesia teaching recommends withdrawing a tube advanced into the right main bronchus until bilateral breath sounds are equal (
Morgan and Mikhail text excerpt).