Improving post-thyroidectomy care using a PTH and calcium-based algorithm

INTRODUCTION: Thyroidectomy is a fundamental therapeutic intervention for various thyroid disorders, yet it entails significant risks, including iatrogenic hypoparathyroidism. Since 2019, our institution has implemented a standardized post-thyroidectomy protocol using parathyroid hormone (PTH) and calcium measurements to stratify hypocalcemia risk and guide calcium and alfacalcidol supplementation. OBJECTIVE: This study aimed to assess the effectiveness of this structured approach in reducing unscheduled referrals due to hypocalcemia within three weeks after total thyroidectomy and evaluate the utility of early postoperative PTH levels in predicting permanent hypoparathyroidism (PhP). METHODS: A retrospective observational cohort study was conducted at Radboud UMC Nijmegen, including 373 adult patients who underwent total/completion thyroidectomy between January 2014 and April 2025. Patients were assigned to either the post-protocol cohort (PPC) (N = 154) or the historic cohort (N = 219), depending on whether surgery occurred after or before protocol implementation, and subsequently compared. RESULTS: Unscheduled referrals were significantly more frequent in the historic cohort than in the PPC (19.2% vs. 11% respectively, p = 0.034), and the introduction of the protocol was associated with a significant reduction in the odds of these referrals. Early postoperative PTH levels were a significant predictor of unscheduled referrals (p = 0.003), postoperative hypocalcemia (p < 0.001) and PhP (p < 0.001). A postoperative PTH cutoff of 1.7 pmol/L was identified as a clinically meaningful threshold for PhP prediction, demonstrating 100% sensitivity. CONCLUSIONS: Subject to assay availability and workflow efficiency, implementation of this protocol may reduce post-thyroidectomy emergency consultations and readmissions, improving healthcare resource utilization and optimizing follow-up.