Final answer:
Dilated pupils are a critical sign in a patient with increased ICP and warrant immediate action. Rapid neurological assessments are crucial in emergencies to guide treatment.
Step-by-step explanation:
The change in the status of a patient being treated for increased intracranial pressure (ICP) that warrants immediate action by the nurse is B) Dilated pupils. This can indicate herniation of the brain due to increased ICP, a life-threatening situation that demands urgent medical intervention. A rapid assessment of neurological function, as in emergency situations, is vital because it helps identify issues such as strokes or trauma to the nervous system, enabling timely and appropriate treatment. It's important to note also that sudden improvement in neurological function could be misleading, as it may suggest transtentorial herniation. However, the presence of dilated pupils is an immediate and definitive sign of neurological deterioration requiring swift action.