The use of impedance respirometry to confirm tracheal intubation in children

Accidental oesophageal intubation can occur in children and is a cause of morbidity and mortality. This study investigated the use of impedance respirometry to determine tracheal tube position in children aged 1-10 years. Eighty children were recruited and, after induction of anaesthesia, two identical tracheal tubes were inserted: one into the trachea and one into the oesophagus. The breathing system was attached to one of the tubes chosen at random. A blinded observer was asked to identify the position of the tube within six breaths using impedance respirometry. The positions of 76 out of 80 tubes were correctly identified. Of those incorrectly identified, one was in the trachea and three were in the oesophagus. The sensitivity of the test was 0.975 and the specificity 0.925. The median number of breaths needed to identify the position of the tubes was 2.0 for both groups. This is not a perfect technique in the population studied but when used with other methods of tracheal tube position identification, its use could decrease the time taken to identify incorrect placement.