Hypocalcemia Post Total Thyroidectomy: A Ten-Year, Single Institution Experience With a Parathyroid Hormone-Guided...

To report 10-year experience with a parathyroid hormone (PTH)-guided calcium (Ca) and calcitriol supplementation protocol in reducing the incidence of hypocalcemia after total thyroidectomy (TT).

Single-institution, retrospective chart review of patients who underwent TT. One hundred forty-eight patients had an operation prior to the protocol introduction and 735 had surgery after the protocol was started. Total serum Ca < 8 mg/dL was defined as hypocalcemia. The 4-hour PTH stratified patients into low (>30 pg/mL), intermediate (15-30 pg/mL), and high (<15 pg/mL) hypocalcemia risk groups, to guide Ca and calcitriol management. Demographic information, preoperative and postoperative characteristics, and outcomes were recorded. Fisher's exact test and Wilcoxon rank sum test were used to compare the characteristics between the 2 groups. Multivariable logistic regression was used to account for confounding variables. Area under the ROC curve was used to determine optimal 4-hour PTH value as predictor of hypocalcemia.

The postprotocol group had significantly lower hypocalcemia incidence (9.9% vs 20.9%, P < .001) and related readmissions (0.9% vs 4.7%, P = .004) than the preprotocol group. Lymph node dissection and parathyroids embedded in thyroid tissue were significant risk factors for hypocalcemia. Hypocalcemia occurred in 24.3% of patients with PTH <15 pg/mL vs 2.3% with PTH >30 pg/mL. Lymph node dissection and parathyroids embedded in thyroid tissue were significant risk factors.

A PTH-guided Ca and calcitriol supplementation protocol significantly reduces post-TT hypocalcemia and related readmissions and may represent a useful approach in managing suitable candidates for outpatient TT.