**Core Concept**
In the context of endotracheal intubation, cuff pressure is crucial to prevent mucosal ischemia and damage to the tracheal wall while maintaining a secure airway. Proper cuff pressure is essential, especially in patients requiring prolonged ventilation.

**Why the Correct Answer is Right**
The optimal cuff pressure for endotracheal intubation is less than 20-25 cmH2O to prevent tracheal mucosal ischemia and stenosis. High cuff pressures can lead to mucosal damage, whereas low pressures may result in leaks and inadequate ventilation. The tracheal mucosa is sensitive to pressure, and cuff pressures above 30 cmH2O can cause ischemia and potentially lead to tracheal stenosis.

**Why Each Wrong Option is Incorrect**
**Option A:** 10-15 cmH2O is too low and may lead to leaks and inadequate ventilation.
**Option B:** 30-35 cmH2O is too high and may cause tracheal mucosal ischemia and stenosis.
**Option C:** 40-45 cmH2O is excessively high and can cause severe tracheal damage and mucosal ischemia.

**Clinical Pearl / High-Yield Fact**
To ensure proper cuff pressure, it is essential to regularly check the cuff pressure using a manometer, especially in patients requiring prolonged ventilation. A cuff pressure above 20-25 cmH2O should be avoided to prevent tracheal damage.

**Correct Answer: D. 30-35 cmH2O is too high and may cause tracheal mucosal ischemia and stenosis**