A 5-year-old child is recovering after undergoing surgery for a brain tumor. The nurse is reviewing the child's postoperative care plan. The child is alert, but the nurse notices that the child is vomiting and complaining of a headache. The nurse's priority action should be:

A. Encouraging the child to drink fluids to stay hydrated is incorrect because while hydration is important, the priority is identifying and managing potential increased intracranial pressure (ICP). Giving fluids before assessing neurological status may delay recognition of a serious complication. B. Positioning the child in a flat supine position is incorrect because a flat supine position can actually increase ICP. Postoperative positioning for brain surgery typically involves head elevation (30 degrees) to promote venous drainage and reduce ICP, unless contraindicated. C. Administering an antiemetic to control vomiting is incorrect as controlling vomiting is secondary. Vomiting can be a sign of increased ICP, so addressing the underlying cause is more important than treating symptoms alone. D. Assessing the child's neurological status and checking for signs of increased intracranial pressure is correct. Vomiting and headache after brain surgery are red flags for increased ICP, which can lead to life-threatening complications such as brain herniation. Priority nursing actions include frequent neurological assessments (level of consciousness, pupil size and reactivity, motor function), monitoring vital signs for changes in blood pressure, pulse, and respiration (Cushing’s triad), notifying the healthcare provider immediately if ICP is suspected, and implementing interventions to reduce ICP, such as proper positioning, oxygenation, and minimizing stimuli.