Duke WS, et al. - Researchers investigated 316 participants to assess how preoperative core-laboratory parathyroid hormone (CL-PTH) level and the baseline intraoperative PTH (IOPTH) level were related and the impact of any changes on clinical decision making in successive surgical patients with primary hyperparathyroidism undergoing parathyroidectomy. They observed higher levels of baseline IOPTH measurements with a mean difference of 68.2 pg/mL in more than 75% of subjects undergoing parathyroidectomy. They suggested that prolongation of the operation in some cases could result from employment of CL-PTH as a surrogate of an IOPTH baseline value.