Cost Savings Associated with Post-thyroidectomy Parathyroid Hormone Levels

Objectives: A 1-hour post-thyroidectomy parathyroid hormone (PTH) level of < or =8 ng/L is predictive of patients who will develop hypocalcemia and guides early supplementation with calcium and vitamin D. However, most hypocalcemic patients fail to meet this criterion. The goal of this study was to determine whether PTH < or = 15 ng/L could be used as a better predictor of hypocalcemia. STUDY DESIGN, SUBJECTS, AND METHODS: This retrospective study involved 270 thyroidectomy patients (2004-2006). PTH and calcium levels, length of admission, supplementation, and rates of hypocalcemia were recorded.

Results: Forty-three percent (26/60) of patients developing hypocalcemia met the PTH < or = 8 ng/L cut-off. In contrast, 80% (48/60) of patients developing hypocalcemia had a PTH < or = 15 ng/L. Two point two percent of patients had a 1-hour PTH < or = 15 ng/L and failed to develop hypocalcemia, for a specificity of 97%.

Conclusions: A 1-hour PTH cut-off of < or =15 ng/L for prophylactic supplementation should allow the prevention of the majority of cases of hypocalcemia, leading to significant cost savings by shortening hospital stays.