Final answer:
Absent breath sounds over the left chest would indicate that the endotracheal tube has likely been inserted too far, advancing into the right bronchus and resulting in inadequate ventilation to the left lung.
Step-by-step explanation:
The question pertains to identifying the indication that an endotracheal (ET) tube was advanced too far into the trachea based on auscultation of breath sounds. Auscultation is a procedure where clinicians use a stethoscope to listen to the internal sounds of the body. When the ET tube is inserted too far, it may advance into one of the main bronchi, typically the right bronchus due to its more vertical alignment. This would lead to breath sounds being heard on one side (the intubated side) and absent breath sounds on the other. Therefore, absent breath sounds over the left chest would indicate the ET tube was too far and potentially into the right bronchus, not providing adequate ventilation to the left lung.