Role of preoperative serum calcium levels in predicting postoperative transient hypocalcemia in patients undergoing hemithyroidectomy surgery

Background: There is increase in incidence of thyroid disease and thyroid surgery over the years, mostly affecting females. Hypocalcemia following thyroid surgery can be fatal and increases hospital stay and cost. Transient hypocalcemia in postoperative period following hemithyroidectomy is seldom seen and often overlooked. We studied the role of preoperative serum calcium levels in predicting the postoperative transient hypocalcemia in patients undergoing hemithyroidectomy. Methods: This is a prospective study on patients undergoing hemithyroidectomy at tertiary care hospital from June 2022 to February 2023. The serum calcium levels were recorded preoperatively and in immediate postoperative period (within 24 hrs after surgery). The serum calcium level of 9-11 mg/dl was considered normal range and level below 9 mg/dl was considered as hypocalcemia. Results: Gender distribution was 50 females (90.9%) and 5 males (9.09%) with mean age of 38.6 years. Out of 55 patients who underwent hemithyroidectomy, 15 patients had low serum calcium levels (<9 mg/dl) preoperatively. Out of these 15 patients, 10 patients (66.6%) developed postoperative transient hypocalcemia. None of the patients had symptoms of hypocalcemia in postoperative period. Conclusions: The preoperative serum calcium levels can predict the postoperative transient hypocalcemia in patients undergoing hemithyroidectomy surgery. In two-thirds of patient who had serum calcium levels below 9 mg/dl preoperatively developed postoperative transient hypocalcemia. Further studies are required to know the cause of low serum calcium levels preoperatively and postoperative transient hypocalcemia in patients undergoing hemithyroidectomy surgery.