The esophageal detector device. Does it work?

The esophageal detector device (EDD) is a diagnostic tool for confirmation of tracheal intubation. Capnography is the accepted standard for such confirmation. The purpose of this investigation was to determine whether results using the EDD and capnography agree.

Five hundred patients were divided into three separate studies. In study 1, with 300 consecutive patients, tracheal intubation was performed and tested with the EDD followed by capnography. In study 2, 100 patients had the esophagus intentionally intubated, and confirmation was tested similarly. The tube was then removed and the trachea intubated, and testing followed. Study 3 involved 100 patients and used a double-blind, randomized design. The tube was intentionally inserted into either the esophagus (n = 5) or trachea (n = 49), and testing followed.

In study 1, the compressed EDD bulb reinflated 270 times and always agreed with capnography; in 20 of the 270 subjects (7%) bulb reinflation was delayed, taking from 5-30 s. In 30 instances, the bulb remained compressed, and there was no capnogram indicating esophageal intubation. In study 2, regardless of esophageal or tracheal intubation, agreement between EDD and capnogram was 100%. In study 3, the agreement between the two detecting instruments was 100%, but reinflation of the EDD bulb was delayed in 4% of tracheal intubations. In the 500 patients studied, results from the EDD and capnogram always agreed, but in 6% of all tracheal intubations, the EDD bulb inflated slowly. Of 181 esophageal intubations, the results from the EDD and capnogram always agreed, i.e., there was no reinflation or capnogram. The sensitivity, specificity, and predictive value for the EDD in all of these studies was 100%.

The EDD is a valuable diagnostic technique for confirming tracheal intubation. Results using EDD agree with results using capnography; in 6% of instances there is a slow reinflation; and where there is no capnography, such as on hospital wards, EDD may be a useful diagnostic tool.