A nurse is caring for a client with Ménière's syndrome who is experiencing an acute episode of vertigo. Which nursing intervention should the nurse implement first?

Immediate Priority: Fall prevention is paramount. The first and most critical action is to assist the client to a supine position on a firm, low surface (e.g., bed or floor) with side rails raised and padded if possible.

Environmental Control: Dim the lights and reduce noise. A quiet, darkened room minimizes conflicting sensory input that can worsen vertigo and nausea. Avoid sudden movements or jarring the client's bed.

Pharmacological Management: Administer prescribed vestibular suppressants (e.g., meclizine, diazepam) and antiemetics after ensuring physical safety. These medications are secondary to stabilizing the patient's position.

Patient Education & Support: Instruct the client to keep their head still and eyes open, focusing on a fixed point if possible. Provide calm reassurance, as anxiety can intensify symptoms. Advise them to avoid sudden position changes.

Ongoing Monitoring: Stay with the client during the acute phase. Monitor vital signs and assess for dehydration if vomiting is severe. Keep the call light within reach and instruct the client to call for assistance before attempting to get up.