Which method best confirms endotracheal tube placement?

• A. Chest auscultation
• B. Oximetry
• C. Radiographic confirmation
• D. End-tidal CO2 detector

Answer: (D)

Verifying endotracheal tube placement hinges on detecting exhaled carbon dioxide. The end-tidal CO2 detector, or capnography, gives breath-by-breath evidence of CO2 in the airway and shows a regular waveform when the tube is in the trachea. This immediate feedback lets you confirm correct placement and continuously monitor the tube’s position with each breath, which is crucial during rapid airway management.

Chest auscultation can be helpful but is not reliable on its own because sounds can be misleading—air may be heard over the chest even if the tube is in the esophagus, or movement and other factors can mask the true location. Oximetry measures oxygenation, not tube placement, and values can stay normal for a time even if the tube is misplaced. Radiographic confirmation is accurate but not immediate; it requires imaging access and time, making it unsuitable for rapid confirmation in emergent scenarios.