Confirmation of nasogastric tube placement by colorimetric indicator detection of carbon dioxide: A preliminary report

Background: inadvertent insertion of nasogastric tubes into the trachea and distal airways is reported to range from 0.3% to 15% of insertions. Critically ill, mechanically ventilated patients are at a higher risk for such complications, some of which can be fatal. Objective: This preliminary prospective clinical investigation was designed to determine whether a colorimetric carbon dioxide (CO2) indicator device (Easy-Cap (TM), Nellcor, Inc., Hayward, CA) attached to the proximal end of a small bore feeding tube (FT) would reliably discriminate between those tubes passed into the airways and those passed into the alimentary tract. Methods: Ten critically ill, mechanically ventilated trauma patients requiring a FT insertion were evaluated. An Easy-Cap (TM) device was adapted to the proximal port of each FT. Each patient had one tube inserted per the nasogastric route and then another through the endotracheal tube while the Easy-Cap (TM) was observed for color changes consistent with the presence of CO2. Results: All transtracheal insertions showed immediate and unambiguous color changes consistent with the presence of CO2. None of the nasogastric insertions resulted in indicator color changes and all were confirmed with radiography (sensitivity 100%, specificity 100%, accuracy 100%). Conclusions: This preliminary report suggests colorimetric CO2 detection accurately and reliably identifies transtracheal FT insertion.