A 29-year-old woman undergoes thyroidectomy for Graves' disease with ophthalmopathy. She was treated with antithyroid drugs and beta-blockers preoperatively. Physical examination and laboratory results prior to surgery were unremarkable. Her ophthalmopathy was characterized as moderate with no corneal involvement or visual loss.
The patient has no immediate surgical complications. Twenty-four hours after extubation, she reports feeling anxious and is irritable. She has paresthesias of her hands and around her lips. Six hours later, shortly after a nursing shift change, she complains of trouble breathing and has a high-pitched inspiratory sound. A quick inspection of her neck bandages reveals no hemorrhage.
What is the most likely cause of her dyspnea?

Question

A 29-year-old woman undergoes thyroidectomy for Graves' disease with ophthalmopathy.  She was treated with antithyroid drugs and beta-blockers preoperatively.  Physical examination and laboratory results prior to surgery were unremarkable.  Her ophthalmopathy was characterized as moderate with no corneal involvement or visual loss.
The patient has no immediate surgical complications.  Twenty-four hours after extubation, she reports feeling anxious and is irritable.  She has paresthesias of her hands and around her lips.  Six hours later, shortly after a nursing shift change, she complains of trouble breathing and has a high-pitched inspiratory sound.  A quick inspection of her neck bandages reveals no hemorrhage.
What is the most likely cause of her dyspnea?

Quizplus · Accepted Answer

This patient most likely has laryngospasm from hypocalcemia caused by transient or permanent hypoparathyroidism. Transient hypocalcemia is common in the first 24 hours after total thyroidectomy, occurring in about 60-90% of patients. Monitoring postoperative serum calcium and aggressively repleting calcium, either orally or intravenously, avoids complications of hypocalcemia. Laryngospasm causing inspiratory stridor after thyroidectomy is a medical emergency. The timing of stridor after thyroidectomy can provide a clue to its cause. If respiratory distress or stridor is apparent immediately upon extubation, bilateral recurrent laryngeal nerve injury is likely (Choice B). Stridor appearing within a few hours of surgery suggests possible wound hematoma with tracheal compression (Choice E). Prompt removal of bandages and examination of the wound for swelling should be performed. Stridor appearing later, especially if preceded by paresthesias or muscle cramps, suggests hypocalcemia from transient hypoparathyroidism or inadvertent parathyroidectomy. (Choice A) Clinical manifestations of acute lung injury (ALI) include tachypnea, tachycardia, and hypoxemia; physical examination reveals diffuse rales. There is usually a precipitating event such as sepsis, massive trauma, or transfusion. Pulmonary dysfunction occurs 48-72 hours after the precipitating event and progresses rapidly. This patient does not have precipitating events or clinical signs of ALI. (Choice D) Tracheomalacia (diffuse or segmental tracheal weakness) presents with dyspnea, cough, increased sputum production, wheezing, or stridor. Acquired causes of tracheomalacia include prolonged intubation, chest wall trauma, severe emphysema, and compression from a lesion. This patient had an uncomplicated surgical course and was extubated in < 24 hours, making tracheomalacia unlikely. Educational objective: Stridor after total thyroidectomy is a medical emergency. Evaluation for wound hematoma and the possibility of hypocalcemia and bilateral nerve injury is needed to assure a patent airway. __________ References: Diagnosis and management of hypocalcemia. (http://www.ncbi.nlm.nih.gov/pubmed/18535072) Hypomagnesemia and hypocalcemia after thyroidectomy: prospective study. (http://www.ncbi.nlm.nih.gov/pubmed/10773126) Patterns of post-thyroidectomy hemorrhage. (http://www.ncbi.nlm.nih.gov/pubmed/19565031)

A 29-Year-Old Woman Undergoes Thyroidectomy for Graves' Disease with Ophthalmopathy