Hypocalcemia following hemithyroidectomy

Hypocalcemia as a manifestation of hypoparathyroidism is a well recognized complication of total thyroidectomy. Less well recognized is the possibility of hypocalcemia following subtotal thyroidectomy. A prospective observational series of 107 patients undergoing hemithyroidectomy was evaluated by preoperative serum calcium and albumin determinations as well as serum calcium determinations at one and seven days postoperatively. There was a significant decrease in mean calcium concentration from the preoperative determination (9.1 mg/dL) to postoperative day one determination (8.4 mg/dL) and then a significant mean increase in the calcium concentration from postoperative day one to day seven (9.0 mg/dL). There was no statistical difference between the mean preoperative calcium concentration and the day seven mean calcium concentration. Additional analyses failed to show a significant relationship between repeated calcium determinations and either disease pathology (benign versus malignant), sex, or race. At one week post surgery, patients' serum calcium normalized. Thus the need for calcium replacement or prolonged hospitalization was generally not necessary. The possible exceptions are patient's with low or low normal calcium preoperatively, unknown status of their parathyroid glands (i.e., previous thyroid surgery), devascularization/resection of parathyroid tissue at the time of surgery and patients undergoing completion thyroidectomy.