To investigate the risk factors of early hypocalcemia after total thyroidectomy.

A retrospective study was conducted in 715 patients who underwent total thyroidectomy for thyroid cancer from January 2016 to June 2019. Statistical analysis were performed by using SPSS 24.0 software. Risk factors of early hypocalcemia were analyzed by using chi-square test, t test or nonparametric test. Logistic model were employed for multiple factors analysis. A P value of <0.05 was considered as statistically significant difference.

There were 297 cases (41.5%) of postoperative hypocalcemia, including 228 cases (76.8%) of asymptomatic hypocalcemia, and 69 cases (23.2%) with clinical symptoms. Among them, gender, BMI (body mass index), serum calcium on the 1st day after surgery, PTH on the 1st day after surgery, PTH on the 3rd day after surgery, number of cancer lesions, number and range of CLND were risk factors for early postoperative hypocalcemia (P<0.05). In the multivariate analysis, gender (P=0.003), BMI (P=0.005), CLND sweep range (P=0.019), PTH on the 1st day after surgery (P=0.033), and number of cancer lesions (P=0.011) were independent risk factors.

Women, low body weight, unilateral or bilateral central lymph node dissection, significant decrease of PTH on the first day after surgery, and more than two cancer lesions are independent risk factors for early hypocalcemia.