NBME 17 PTH and Calcium Q post thyryoidectomy - panmedic

[ArchivalUser]

1. S3Q50 50. A 59-year-old man undergoes a total thyroidectomy and central lymph node dissection for a 4-cm follicular carcinoma of the thyroid. Twelve hours after the procedure, he has paresthesias of his hands and feet. Vital signs are stable, but carpal spasm is noted on inflation of the blood pressure cuff. Which of the following sets of laboratory findings in serum is most likely in this patient? Parathyroid Hormone Calcium

[ArchivalUser]

Right answer is decreased PTH and decreased calcium. but can anyone explain why

[ArchivalUser]

Ok i get it, it's because of the unwanted microresection of Parathyroid glands, there is tetany.