[Verification of the endotracheal tube placement].

Verification of the correct position of the endotracheal tube is a daily routine task of every anaesthesiologist. Accidental intubation of the oesophagus is a very rare complication in absolute terms but still the most frequent preventable anaesthetic mishap with fatal outcome. Even the most experienced anaesthetist is not immune to this complication. Only vigilance on the part of the anaesthetist protects the patient. There is no absolutely reliable gold standard to diagnose the correct position of the tracheal tube. Visualization of the endotracheal tube between the vocal cords and a typical CO2 excretion waveform are two of the best practical signs. After every change of position of the patient, especially after flexion or extension of the head, the position of the tube must be checked again. The old aphorism is still valid: When in doubt, take it out.