Which adjunct device is preferred to verify endotracheal tube placement in a patient with a perfusing rhythm?

• A. Esophageal detector device
• B. Stethoscope
• C. End-tidal CO2 monitoring (capnography)
• D. Pulse oximeter

Answer: (C)

End-tidal CO2 monitoring (capnography) directly confirms that the endotracheal tube is in the trachea by detecting exhaled CO2 and displaying a waveform with each breath. In a perfusing patient, CO2 is produced and expelled, so the presence of a robust capnography waveform verifies correct placement and allows continuous monitoring for dislodgement or ventilation issues. If the tube were in the esophagus, little to no CO2 would be detected and the waveform would be flat, prompting immediate rechecking.

Other methods are less reliable for placement confirmation. An esophageal detector device can fail or be misleading in some conditions and isn’t continuous monitoring. A stethoscope may help in a rough check but cannot reliably distinguish tracheal from esophageal placement. A pulse oximeter shows oxygenation status, which can appear acceptable even with misplacement for a short time and does not confirm tube location. Capnography provides the most direct, immediate, and ongoing confirmation of correct endotracheal placement.