Which one of the following assessments is most appropriate for determining the correct placement of an endotracheal tube in a mechanically ventilated client?

A. While skin color can indicate oxygenation status, it does not confirm tube placement. Cyanosis may appear late, and relying solely on skin color can delay recognition of incorrect placement. B. Respiratory rate shows ventilatory pattern but cannot reliably confirm endotracheal tube position. A patient may breathe or be ventilated even if the tube is in the esophagus or mainstem bronchus. C. Checking cuff inflation ensures a seal to prevent air leaks, but it does not indicate proper tracheal placement. An inflated cuff in the esophagus would not prevent misplacement. D. Auscultation of bilateral breath sounds over the lungs is a primary bedside assessment for confirming proper endotracheal tube placement. Absence of sounds on one side may indicate mainstem intubation, while no breath sounds with epigastric gurgling suggests esophageal placement. This assessment is immediate, noninvasive, and critical before confirming with a chest x-ray.