Which of the following is a reliable method to confirm ETT placement?

• A. Imaging
• B. Auscultation of breath sounds
• C. Symmetric chest rise
• D. End-tidal CO2 waveform

Answer: (D)

End-tidal CO2 waveform provides real-time confirmation that the endotracheal tube is in the trachea and that ventilation is occurring. When the tube is properly placed, CO2 produced by metabolism is expelled through the lungs and detected by capnography, producing a recognizable waveform with each exhalation and a measurable end-tidal CO2 value. This immediate, ongoing feedback helps you verify placement quickly and monitor tube position during transport or ongoing resuscitation. If the tube were in the esophagus, there would be little or no CO2 detected, resulting in a flat or absent waveform, signaling misplacement.

Imaging can confirm placement, but it isn’t instantaneous and may not reflect current position during movement or chest compressions. Auscultation of breath sounds and looking for symmetric chest rise can be misleading, since sounds can be muffled, transmitted, or falsely reassuring, and chest rise alone does not guarantee tracheal placement. Therefore, the ETCO2 waveform is the most reliable single method for confirming endotracheal placement in real time.