AB084. SOH24AB_270. Perioperative monitoring of calcium levels after minimally invasive radio guided parathyroidectomy (MIRP) for early detection of hypocalcemia and its management: an observational study

Background: Minimally invasive radio guided parathyroidectomy (MIRP) is the gold standard treatment for primary hyperparathyroidism. Incidence of transient hypocalcemia after parathyroidectomy is reported as high as 35%, however there is insufficient evidence for incidence of hypocalcemia after MIRP. The guidelines on postoperative monitoring of calcium levels after MIRP are also unclear. Hypocalcemia can be divided into transient which occurs within 48 hours of surgery; temporary that may last up to 6 months post-surgery and permanent which lasts more than 6 months of surgery. It can be secondary to surgical manipulation or hungry bone syndrome.

Methods: Retrospective observational study, to determine the incidence of transient hypocalcemia after MIRP and development of a protocol for monitoring of serum calcium levels for early detection of hypocalcemia and its appropriate management.

Results: From January–November 2023, 46 MIRP and 2 Redo MIRP were performed in our unit.18 patients stayed overnight (logistic reasons) and the rest were discharged postoperatively. Admitted patients had repeat calcium levels within 24 hours. All patients were discharged on calcium supplements for two weeks and calcium levels were repeated on day 6 when they returned for review. One (2.1%) patient developed symptomatic hypocalcemia post-operatively with calcium level of 2.1 mg/dL.

Conclusions: The incidence of hypocalcemia after MIRP is low, therefore, avoiding routine investigations in immediate postoperative period for day cases is a safe practice and calcium supplementation decreases chances of hypocalcemia.

Keywords: Minimally invasive radio guided parathyroidectomy (MIRP); primary hyperparathyroidism; hypocalcemia; protocol; hungry bone syndrome