The Perioperative Management of the Voice and Serum Calcium Levels
The complications of laryngeal nerve injury and hypoparathyroidism are relatively uncommon with thyroid surgery. Injury to the recurrent laryngeal nerve results in a hoarse voice, while injury to the external branch of the laryngeal nerve can result in loss of high-pitched vocal range or projection. Neuropraxia, or stretch injury, to the recurrent laryngeal nerve is often transient and will recover over 2–3 months following surgery. Laryngoscopy is the gold standard for diagnosis of vocal cord abnormalities after thyroidectomy. Treatment of vocal cord dysfunction includes voice therapy and operative approaches that aimed at medialization of the paralyzed cord so as to improve adduction and apposition of the vocal cords during phonation which results in more normal voice. Injury or removal of the parathyroid glands during thyroidectomy can result in hypoparathyroidism causing subsequent hypocalcemia. The initial symptoms of hypocalcemia include paresthesias of the extremities, and perioral area can progress to tetany, seizures, and arrhythmias in severe cases. Postoperative supplementation with calcium with or without vitamin D is used in the treatment of hypocalcemia and as prophylaxis against the development of symptoms during inadequate parathyroid hormone production. Routine calcium and vitamin D supplementation or supplementation based on postoperative calcium or parathyroid hormone (PTH) levels are both viable options. Temporary hypoparathyroidism occurs in about a third of patients after bilateral thyroidectomy; however, permanent hypoparathyroidism is rare.
KeywordsThyroidectomy Recurrent laryngeal nerve External branch superior laryngeal nerve Paralysis Paresis Injury Voice Hoarseness Parathyroid Hypoparathyroidism Hypocalcemia Parathyroid hormone
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