What is the gold standard for confirming endotracheal tube placement?

• A. Waveform capnography
• B. Auscultation
• C. Chest X-ray
• D. End-tidal CO2 colorimetric device

Answer: (A)

Waveform capnography provides real-time verification of ventilation by showing a continuous CO2 waveform along with a numerical end-tidal CO2 value. When the tube is in the trachea and the patient is being ventilated, exhaled CO2 appears on the waveform, confirming tracheal placement and a functioning airway. The waveform also helps detect tube dislodgement or esophageal intubation immediately—if the tube is in the esophagus, little to no CO2 is detected and the waveform is flat. This immediate feedback is why it’s considered the gold standard for confirming placement.

A colorimetric end-tidal CO2 device can indicate the presence of CO2 with a color change, but it does not provide a continuous waveform or precise numeric values, making it less reliable in ambiguous situations or poor perfusion. Auscultation and chest X-ray have roles in assessment, but auscultation can be misleading in noisy or CPR conditions, and chest X-ray, while useful, is not immediate and may delay confirmation in the field.