SAT223 Persistent Hypocalcemia After Thyroidectomy

Disclosure: R. Subramani: None. F. Manas: None. A. Kauser: None. S. Yavuz: None. Introduction: Hypocalcemia is one of the serious complications after total thyroidectomy with a reported incidence of 27.4% (transient)and 12.1% (permanent) probably related to iatrogenic parathyroidectomy. Here we report a case of hypocalcemia after thyroidectomy in the setting of normal parathyroid hormone levels. Summary: A 42-year-old female with medical history of multinodular goiter s/p thyroidectomy 2019 on thyroid hormone replacement presented with hypocalcemia since 2021. During the first-year post thyroidectomy, patient was doing well until she acquired COVID-19 in 2020 and started developing symptoms of paresthesia, and muscle spasms. Other parameters such as phosphorus, and 25 OH vitamin D were normal. Despite being on a high-dose calcium supplement 1200 mg every hour for 10 times daily and calcitriol 0.75 mg twice daily, her calcium levels were persistently low ranging between 7.1 to 8 mg/dl and normal albumin levels of 3.9 and 4.3, but parathyroid level (PTH) remained normal (27.7-37.5). The patient was also symptomatic. She was later switched to liquid calcium 1000 mg 6 times daily for better absorption. It is noted that she had recurrent symptomatic hypocalcemia episodes requiring multiple emergency room (ER) visits during times of stress such as viral illness. The patient was treated with a trial of teriparatide, after which her symptoms improved and there were no further ER visits. Her calcium level increased from 7.4 to 8.4 and calcium supplement requirement reduced to 1200 mg daily. During recent outpatient visit, the patient had hypocalcemia episodes after missing teriparatide doses as expected. Conclusion: Despite our patient had normal PTH levels, the parathyroids glands did not respond appropriately to hypocalcemia. Promberger et al studied a case of eight patients with hypocalcemia with normal PTH following thyroidectomy. All these patients had normal PTH levels during post-op period, but persistently low and ionized calcium levels 12 months after surgery. This suggests during persistent hypocalcemia normal parathyroid levels may indicate an inadequate PTH response. In our case, developing hypocalcemia long after surgery and relation to COVID-19 infection may suggest autoimmune phenomenon as developing PTH-antibodies or receptor malfunction, theory yet to be investigated. In cases of severe symptomatic hypocalcemia requiring significant amount of calcium supplement PTH analogs are very effective treatment. Presentation: Saturday, June 17, 2023