It is widely accepted and taught that the accidental placement of a tracheal tube in the oesophagus can be readily detected if it is looked for, though it is recognised that death from this cause occurs from time to time. Evidence is now presented of instances where anaesthetists have been misled by a range of tests which are commonly used to check the correct placement of a tracheal tube. An explanation is offered for this unexpected finding, and some recommendations are formulated to improve patient safety.
