[Anesthesia and postoperative recovery for parathyroid gland surgery]

Abstract

Anesthesia for surgery of primary hyperparathyroidism (HPT) usually concerns asymptomatic elderly women with moderate hypercalcemia. Cardiovascular repercussions of the endocrine disorder are possible, but they are not frequent except for hypertension. Hyperparathyroid crisis is a life-threatening condition with severe hypercalcemia. Intravenous diphosphonates are very effective drugs to control hypercalcemia. The improvement is transient but allows curative parathyroidectomy to be performed with a minimal risk of cardiac arrhythmias. Anesthesia for surgery of secondary HPT concerns patients with chronic renal failure treated by hemodialysis. Cardiovascular disease is frequent and aggravated by the endocrine disorder. In patients with marked aortic stenosis or severe left ventricular dysfunction, parathyroidectomy should be performed by cervicotomy under local anesthesia. Hyperparathyroidism may persist after renal transplantation (tertiary HPT): in this case cardiovascular disease is minimal and the hypercalcemia is moderate. Parathyroidectomy is usually performed by cervicotomy under general anesthesia. Sternotomy is required in the case of an abnormal mediastinal location of a gland. An interaction between myorelaxants and hyperparathyroidism has been observed. Total blood calcium must be systematically assayed postoperatively because postoperative hypocalcemia is constant. Hypocalcemia is moderate in primary and tertiary HPT, due to transient functional hypoparathyroidism, with lowest observed the 2nd or 3rd postoperative day. Hypocalcemia should not be treated when asymptomatic because it resolutes on the 4th or 5th postoperative day. Intravenous calcium infusion may be necessary for 1 or 2 days, if serum calcium is below 1.9 mmol per liter with symptoms of tetany. Persistent hypocalcemia is due to an hungry bone syndrome or organic hypoparathyroidism that should be treated by oral vitamin D and calcium. In secondary HPT, hypocalcemia is early, marked and asymptomatic. Treatment must often be started on the 6th postoperative hour by intravenous calcium infusion, followed by oral vitamin D and calcium. The absence of postoperative hypocalcemia indicate incomplete removal of all abnormal parathyroid tissue. At the third postoperative day, a second cervicotomy may be performed to complete the neck exploration.