Occurrence of Clinically Significant Hypocalcemia 6-12 Months Following Total Thyroidectomy could be overrated: Results of a ProspectiveMulticenter Study

Background: Thyroid surgeries are among the most common operations performed in the world. Hypocalcemia following total thyroidectomy is a common complication that is sometimes difficult to correct. The aim of this study was to compare two groups of patients: those with normocalcemia and those with hypocalcemia following total thyroidectomy upon discharge from the hospital and 6 to 12 months following surgery as well as to determine the clinical value. Methods: From January 2015 through April 2017, 400 patients were included in this prospective multicenter study. All the patients underwent total thyroidectomy due to various thyroid diseases. The following risk factors were analyzed: preoperative and postoperative biochemical blood parameters, clinical effects and factors related to surgery, the patient and the disease. By way of random of selection, 2 groups of patients were formed: 30 patients who had a normal level of calcium detected in the blood upon discharge from the hospital following total thyroidectomy (normocalcemia group), and 30 patients who had a reduced level of calcium in the blood upon discharge from the hospital (hypocalcemia group). In these groups of patients, the following parameters were determined: calcium, ionized calcium, 25-hydroxyvitamin D, parathyroid hormone, clinical expression of hypocalcaemia and the use of calcium and 25-hydroxyvitamin D preparations upon discharge from the hospital and 6 to 12 months following surgery. Results: Based on the data of our study, the comparison of patient groups with normocalcemia and hypocalcemia upon discharge from the hospital and 6 to 12 months following surgery demonstrated that there were no statistically significant factors for postoperative hypocalcaemia. Generally, there were no differences between the groups 6 to 12 months following surgery. A reduced level of calcium was determined only in 2 of 30 patients with hypocalcaemia 6 to 12 months following surgery. In the group of patients with normocalcemia, the level of calcium remained normal both on day 2 when they were discharged from the hospital and 6 to 12 months following surgery. Comparing the normocalcemia and hypocalcemia groups on day 2 following surgery and 6 to 12 months following surgery, McNemar’s test showed a statistically significant distribution between these patient groups (pu003c0.01). Of the 2 mentioned patients with hypocalcemia, clinical symptoms were not observed in 1 patient 6 to 12 months following surgery. The patient did not take calcium and calcitriol preparations. Another patient complained about numbness of fingers. The patient used calcium and calcitriol preparations. In the hypocalcemia group, a reduced level of parathyroid hormone was determined in 9 patients on day 1 following surgery. A reduced level of parathyroid hormone was determined in 1 patient of this group 6 to 12 months following surgery. Conclusion: Hypocalcemia following total thyroidectomy is among the most common complications. Treatment with calcium and 25-hydroxyvitamin D preparations after surgery leads to disappearance of both biochemical and clinical expression of hypocalcemia in the majority of cases. Upon discharge from the hospital, patients with more pronounced hypocalcemia should be administered calcium and calcitriol preparations, even in the absence of clinical symptoms.