During an assessment of a 22-year-old woman who sustained a head injury from an automobile accident 8 hours earlier, the nurse notices the following changes: both pupils were equal, but now the right pupil is fully dilated and nonreactive, and the left pupil is 4 mm and reacts to light. What do these findings suggest?

Choice A reason: Simultaneously palpating both carotid arteries is dangerous, risking reduced cerebral blood flow, especially in cardiovascular patients. Using the bell to listen for bruits is safer, so this is incorrect.

Choice B reason: Deep breaths are for lung auscultation, not carotid, where patients hold breath to reduce noise. The bell detects low-pitched bruits, so instructing deep breaths is incorrect for carotid assessment.

Choice C reason: Compressing the carotid artery risks reducing blood flow or dislodging plaques, which is unsafe. Listening with the bell for bruits is the standard method, so this is incorrect.

Choice D reason: Listening with the bell of the stethoscope detects low-frequency bruits, indicating carotid artery narrowing, which is critical in cardiovascular disease. This is the correct technique for safe assessment.

Choice A reason: Normal pupil findings include equal size (2–5 mm) and brisk reaction to light bilaterally. A fully dilated, nonreactive right pupil with a reactive left pupil indicates a neurological abnormality, not a normal finding, as it suggests significant brain dysfunction.

Choice B reason: Rechecking findings is prudent, but the described pupil changes—unilateral dilation and nonreactivity—are classic signs of a serious condition. Delaying action by only rechecking could miss critical intervention timing, as these findings strongly indicate a neurological emergency.

Choice C reason: A unilaterally dilated, nonreactive pupil with a normal contralateral pupil suggests increased intracranial pressure, often from a hematoma or swelling compressing the oculomotor nerve (Cranial Nerve III). This causes pupil dilation and loss of light reflex, requiring urgent intervention.

Choice D reason: Brainstem injury typically causes bilateral pupil changes, such as fixed, pinpoint, or dilated pupils, due to damage to brainstem nuclei. The unilateral findings here are more indicative of focal pressure (e.g., hematoma) than diffuse brainstem injury, making this less likely.