Tuesday June 24, 2008
Verification of Endotracheal Tube Placement via Esophageal detection devices

Esophageal detection devices are easily used, inexpensive, and have generally demonstrated good utility in detecting esophageal intubations. It is available as either a self-inflating bulb or a syringe device. The EDD relies on the anatomic differences between the trachea and the esophagus. Application of negative pressure, either through aspiration of the syringe plunger or the bulb, leads to the collapse of the esophagus around the end of the endotracheal tube. This is due to the fibromuscular structure of the esophagus, whereas the trachea is very rigid and remains open due to its cartilaginous rings. In an improperly placed endotracheal tube, the bulb will be unable to fully inflate, or the syringe plunger will not be able to completely (or nearly completely) pull back from the body of the syringe.

Advantages:
inexpensive,
portable,
easy to use,
not dependent on environmental conditions (such as good lighting etc).
Unlike the ETCO 2 detector, it works just as well and is just as accurate if the patient is in cardiac arrest

Disadvantages:
false negative can result in obese patients,
false positive can result with a large amount of air in the esophagus,
false negative can result with a large copious pulmonary secretions.
It does not provide an ongoing assessment of continued proper tube placement.