Explanation

**Rationale:** Increased intracranial pressure (ICP) results from swelling or bleeding within the skull, compressing brain tissue. The earliest sign is a **decreased level of consciousness** due to pressure on the reticular activating system, which regulates alertness. This subtle change, such as confusion or lethargy, requires immediate action to prevent further deterioration. **Widened pulse pressure** (e.g., increased systolic BP with stable diastolic BP) occurs later as part of Cushing’s triad, along with bradycardia and respiratory changes. **Pupils fixed and dilated** indicate severe, late-stage ICP from brainstem compression. **Projectile vomiting** is a later sign related to pressure on the vomiting center in the medulla. Early detection enhances patient safety by prompting timely intervention.