In the adult airway confirm-reconfirm protocol, which method is second in accuracy for confirming tube placement?

• A. ETCO2/waveform monitoring
• B. Auscultation
• C. Visualization of ETT protruding past the vocal cords
• D. Bilateral chest expansion

Answer: (A)

In confirming endotracheal tube placement, objective, real-time evidence that the tube is in the trachea is essential. After you visually verify the tube passes between the vocal cords, the next most accurate method is capnography with waveform monitoring. The presence of a consistent end-tidal CO2 waveform confirms that exhaled gas is coming from the lungs, indicating correct placement and ongoing ventilation. This method provides continuous, quantitative feedback and is less susceptible to ambient noise or subjective interpretation than other checks.

Auscultation and watching for bilateral chest expansion can help, but they’re less reliable. Breath sounds can be difficult to hear in noisy environments, with chest injuries, or with irregular ventilation, and chest movement alone doesn’t definitively prove tracheal placement. Visualization of the tube is important, but not always possible or conclusive in every situation. Therefore, ETCO2/waveform monitoring is the second most accurate method for confirming tube placement.