The tube position should always be checked immediately after intubation. In order to avoid over-inflation of the stomach in the case of oesophageal malposition, the first breath should be performed after intubation to check the position of the patient. One should get accustomed with intubated patients after each repositioning immediately a tube position control to carry out, as it is recommended by AHA and ERC.
Note: The pessimist auscultates to control the position of the tube after intubation first above the epigastrium and then above the lungs, the optimist does it the other way round and is often wrong.