Final answer:
End-tidal carbon dioxide (ETCO2) monitoring is the most reliable confirmation for proper tube placement during intubation.
Step-by-step explanation:
The most reliable confirmation for proper tube placement during intubation is end-tidal carbon dioxide (ETCO2) monitoring.
ETCO2 monitoring measures the level of carbon dioxide in exhaled breath, which indirectly indicates proper placement of the endotracheal tube in the trachea.
When the tube is correctly positioned in the trachea, exhaled air will contain higher levels of carbon dioxide. If the tube is misplaced in the esophagus or bronchus, the exhaled air will have lower levels of carbon dioxide.