Hypocalcemia following total
thyroidectomy (TT) must be considered permanent in patients requiring
calcium replacement after one year. The aim of this study was to identify early risk factors predicting long-term outcome of postoperative
hypocalcemia. Among 453 patients who underwent TT from January 1998 to May 2003, a cross-sectional study between 44 patients with transient
hypocalcemia (9.7%) and 3 patients with permanent
hypocalcemia (0.7%) was carried out. Both low serum
calcium level (< 8 mg/dl) and high serum
phosphorus level (> 4.5 mg/dl), measured on postoperative day 7, were predictive for outcome. Central neck
lymph node dissection, performed for
thyroid carcinoma, also correlated with outcome. Serum
phosphorus level > 4.5 mg/dl on postoperative day 7 resulted the only independent factor predicting permanent
hypoparathyroidism. Therefore indication for central dissection would be very strict. When serum
phosphorus level is unfavorable a correct replacement
therapy is mandatory to prevent the consequences of permanent
hypocalcemia.