In initiating the Chvostek sign, the nurse should:

• A. Ask the patient to grimace, and note if the facial response is symmetrical.
• B. Inflate a blood pressure cuff to the systolic level, and watch for a carpopedal spasm.
• C. Tap the face over the facial nerve, and watch for a spasm of the facial muscle.
• D. Check the pupillary response to light, and determine whether the pupil accommodates and reacts.

Answer: (C)

Chvostek sign measures how responsive nerves are when calcium is low. By tapping briskly over the facial nerve just in front of the ear, you trigger a reflexive twitch in the facial muscles if the patient is hypocalcemic. The presence of a facial spasm or twitch on the tapping side indicates a positive sign and suggests hypocalcemia or related neuromuscular irritability, which guides further evaluation and treatment.

This is different from Trousseau sign, which uses a blood pressure cuff to induce carpopedal spasm, and from a pupillary light–reflex test, which assesses cranial nerves and brainstem function rather than electrolyte-related nerve excitability.