Parathyroid hormone levels 1 hour after thyroidectomy: an early predictor of postoperative hypocalcemia

Abstract

Background: Parathyroid dysfunction leading to symptomatic hypocalcemia is not uncommon following a total or completion thyroidectomy and is often associated with significant patient morbidity and a prolonged hospital stay. A simple, reliable indicator to identify patients at risk would permit earlier pharmacologic prophylaxis to avoid these adverse outcomes. We examined the role of intact parathormone (PTH) levels 1 hour after surgery as a predictor of post-thyroidectomy hypocalcemia. Methods:We prospectively reviewed the cases of consecutive patients undergoing total or completion thyroidectomy. Ionized calcium (Ca 2+ ) and intact PTH levels were measured preoperatively and at 1-, 6-and 24-hour intervals postoperatively. The specificity, sensitivity, negative and positive predictive values of the 1-hour PTH serum levels (PTH-1) in predicting 24-hour post-thyroidectomy hypocalcemia and eucalcemia were determined. Results:We reviewed the cases of 149 patients. Biochemical hypocalcaemia (Ca 2+ < 1.1 mmol/L) developed in 38 of 149 (25.7%) patients 24 hours after thyroidectomy. The sensitivity, specificity, positive and negative predictive values of a low PTH-1 were 89%, 100%, 97% and 100%, respectively. Conclusion:We found that PTH-1 levels were predictive of symptomatic hypocalcemia 24 hours after thyroidectomy. Routine use of this assay should be considered, as it could prompt the early administration of calcitriol in patients at ris k of hypocalcemia and allow for the safe and timely discharge of patients expected to remain eucalcemic.

Hypocalcemia posthyroidectomy: prevention, diagnosis and management

“…Accordingly, levels > 7 pg/mL [20], > 9.8 pg/mL [12], > 15 pg/mL [24,28,47], could exclude the development of persistent hypoparathyroidism. However the majority of authors agree with the cutoff < 15 pg/mL (24,28,47) In accordance with the majority of reports we conclude that postoperative iPTH levels < 10 pg/mL are predictors of hypocalcemia with a sensitivity of 72%-97.5%, specificity of 80%-99%, positive predictive value (PPV) of 53%-90% and a negative predictive value (NPV) of 80%-99% [11,16,45,51,52].…”

“…However, the progressive increase in serum calcium values between 6 and 24 hours after surgery, and the finding of normal postsurgical calcium levels, have a high NPV (80%-100%) ruling out the possibility of permanent hypocalcemia and hypoparathyroidism [13,19,31,45,51]. c) 25-Hydroxi-vitamin D 3 levels: Low levels of VD increase the probability of hypocalcemia in the postsurgical period [30,33].…”

An early predictor of postoperative hypocalcemia: parathyroid hormone levels 1 hour after thyroidectomy

“…Qahtani AA et al they prospectively reviewed the cases of consecutive patients undergoing total or completion thyroidectomy. 8 Ionized calcium (Ca…”

Prediction of Transient and Permanent Hypoparathyroidism after Total Thyroidectomy Using the Postoperative Serum Parathyroid Hormone Test: When Is the Best Time to Check?

“…To ensure accurate prediction, it is important to determine the optimal time for measuring iPTH. Various studies have assessed the usefulness of iPTH measurements obtained during surgery, at 1, 4, and 6 hour intervals after surgery, and on the morning of postoperative day 1 (12)(13)(14). Nevertheless, the time point of iPTH measurement that best predicts the parathyroid function prognosis of patients remains unclear (15).…”