A 47-year-old woman visits her physician because she noticed a “lump” in her neck 1 week ago. On physical examination, there is a 2-cm nodule in the right lobe of the thyroid gland. A fine-needle aspiration biopsy is performed, and microscopic examination of the specimen shows cells consistent with a follicular neoplasm. She undergoes a subtotalthyroidectomy. Which of the following laboratory tests should be performed on this patient in the immediate postoperative period?
Inadvertent removal of or damage to the parathyroid glands during thyroid surgery can cause hypocalcemia secondary to hypoparathyroidism.
This is the most common cause of hypoparathyroidism. Individuals with hypocalcemia exhibit neuromuscular irritability, carpopedal spasm, and sometimes seizures.
Calcitonin quantitation is not a useful measure to determine the status of calcium metabolism. The TSH concentration can increase if the patient becomes hypothyroid after surgery and is not receiving thyroid hormone replacement, but this is not an immediate problem.
Parathyroid hormone levels decrease if the parathyroid glands are inadvertently removed during thyroid surgery, but the calcium level is the best immediate indicator of hypoparathyroidism, and this test is more readily available in the laboratory.
Antithyroglobulin antibody levels are of no use in diagnosing surgical diseases of the thyroid.