• Korean Journal of Head & Neck Oncology
• /
• v.11 no.2
• /
• pp.185-190
• /
• 1995

Transient and permanent hypocalcemia after various types of thyroidectomy are well-known complications, and are more common after bilateral subtotal thyroidectomy for Graves' disease. However, their causative mechanisms are not well explained. Four hundred thirty patients with Graves' disease who underwent bilateral subtotal thyroidectomy from January 1983 through December 1992 were analyzed to determine the incidence and risk factors for the development of postthyroidectomy hypocalcemia. Of the 430 patients underwent bilateral subtotal thyroidectomy, symptomatic transient and permanent hypocalcemia developed in 24.2 % (104/430) and 0.5 % (2/430), respectively. With analysis of potential risk factors, the increase in incidence of the postthyroidectomy hypocalcemia was found to be statistically related to the larger thyroid gland, the larger amount of blood loss during thyroidectomy, the smaller remnant thyroid tissue, the higher levels of serum alkaline phosphatase and TBII titers. Our data suggest that impairment of parathyroid gland blood supply, degree of thyrotoxic osteodystrophy and autoimmune process of each patient are regarded as main mechanisms of postthyroidectomy hypocalcemia in patients with Graves' disease.

• Korean Journal of Head & Neck Oncology
• /
• v.15 no.1
• /
• pp.52-60
• /
• 1999

Objectives: For investigation of the differentiation between transient and permanent hypocalcemia, we focused on a postoperative calcium requirement and an interval of normalization in serum hypocalcemic level and studied for the causes of postoperative hypocalcemia. Material and Method: Postthyroidectomy hypocalcemia was studied in 193 patients who were admitted from January, 1991 to December, 1998 and underwent lobectomy, subtotal thyroidectomy or total thyroidectomy. We compared postoperative serum calcium, phosphate and ionized calcium levels among three groups which were lobectomy, subtotal thyroidectomy and total thyroidectomy, respectively. Result: All patients revealed postoperative decline in serum calcium and ionized calcium, especially, the lowest serum calcium level was seen in 48 hours after surgery. Serum calcium level was returned to normal in five to six postoperative days in most patients. But 24 patients required calcium supplementation due to symptomatic hypocalcemia. In this series, we discovered that the important period for monitoring of serum calcium level was 24 to 96 hours after surgery. If the calcium replacement therapy was not required in the first 72 hours after surgery, it would not be needed during the remainder of the patient's hospital course. Symptomatic transient hypocalcemia was 22 cases(11.4%) and permanent hypocalcemia was 2 cases(1%). Conclusion : We found that hypoalbuminemia, preoperative hyperthyroidism and impairment of blood supply to parathyroid were the main causes of postthyroidectomy hypocalcemia. We also thought that the interval from initial medication to normalization in serum calcium level, and the increase of requirement in calcium and vitamin D were the important factors for differentiation between transient and permanent hypocalcemia.