A client returns from a thyroidectomy. During the first 24 hours, which assessment finding requires the MOST immediate response?

POST-THYROIDECTOMY COMPLICATIONS: HYPOCALCAEMIA: Parathyroid glands (regulate calcium) may be inadvertently removed or devascularised during thyroid surgery; EARLIEST SIGNS: Perioral tingling, finger and toe numbness/tingling; CHVOSTEK'S SIGN: Tap the facial nerve at the cheek — positive if facial muscles twitch (abnormal); TROUSSEAU'S SIGN: Blood pressure cuff inflated above systolic — positive if carpopedal spasm occurs; PROGRESSION: Muscle cramps → tetany → laryngospasm (airway emergency) → seizures → cardiac dysrhythmias; NURSING RESPONSE: Notify RN immediately; anticipate: serum calcium level; IV calcium gluconate at bedside; cardiac monitoring; ADDITIONAL POST-THYROID MONITORING: Airway patency (haematoma can compress the trachea); hoarseness (recurrent laryngeal nerve injury — if worsening, notify); thyroid storm (rare — fever, tachycardia, hypertension, agitation); NURSING SCOPE: Assess for all post-op complications; be prepared for airway emergency (tracheotomy tray at bedside for first 24 hrs per facility protocol).