Are preoperative serum calcium, parathyroid hormone, and adenoma weight predictive of postoperative hypocalcemia?

The objective of this study is to determine whether preoperative serum calcium, parathyroid hormone, or adenoma weight is predictive of postoperative hypocalcemia after removal of a parathyroid adenoma. A retrospective chart review was performed for consecutive parathyroidectomy patients over a 6-year period at a community-based teaching institution. Patients with renal failure (serum creatinine >1.7), hyperplastic disease, and parathyroid carcinoma were excluded. The outcome measures were postoperative serum calcium and the presence of signs or symptoms such as paresthesias, anxiety, or Chvostek's sign. One hundred forty-one patients underwent parathyroidectomy during the study period. Fifty-four patients were excluded as a result of hyperplastic disease, renal failure, carcinoma, or unavailable records. Of the remaining 87 patients 25 (28.7%) developed hypocalcemia (serum calcium < 8.0), and ten patients (11.5%), developed symptoms. The mean preoperative calcium levels for the normocalcemic and hypocalcemic groups were 10.9 and 10.6, respectively (P < 0.217). The mean preoperative parathyroid hormone levels (normal 10-54) were 214 and 139, respectively (P < 0.305), and the mean adenoma weights were 1.059 and 1.337 g respectively (P < 0.343). This study demonstrates no statistically significant difference in the mean preoperative serum calcium levels, parathyroid hormone levels, or adenoma weight between normocalcemic and hypocalcemic patients postoperatively.