Which assessment technique is most reliable for detecting proper endotracheal tube placement?

Capnography is the most reliable assessment technique for confirming proper endotracheal tube placement. This method measures the concentration of carbon dioxide in exhaled air, providing real-time feedback on the presence of CO2. When the tube is correctly positioned in the trachea, it allows for effective gas exchange, resulting in the detection of carbon dioxide in the breath. If the tube is misplaced into the esophagus, no CO2 will be detected, indicating that the intubation was unsuccessful.

In contrast, other techniques like chest percussion and pulse oximetry do not specifically confirm tube placement. Chest percussion assesses lung sounds but cannot differentiate between tracheal and esophageal placement. Pulse oximetry measures oxygen saturation, which, while important, does not directly indicate if the endotracheal tube is in the correct position to facilitate ventilation. Blood gas analysis, although useful in assessing a patient's metabolic state and respiratory function, is not practical for immediate confirmation of tube placement at the time of intubation. Therefore, capnography stands out as the most effective and reliable method for ensuring the endotracheal tube is in the correct position.