Endocrine Abstracts

Background: The aim of this study is to compare the value of phosphate measures, which may predict the development of hypocalcemia in the early post operative period following total thyroidectomy, to iPTH and Ca measurements.

Metods: In this prospective study, patients who underwent total thyroidectomy in our clinic between March 2012 and April 2013, independent of diagnosis were included in a consecutive manner. Venous blood samples for calcium (Ca²⁺), phosphate (PO₄³⁻) and iPTH measurements were taken from the study patients ~24 h before surgery and shortly after the patient was brought back to their beds on the surgery ward. Calcium measurements were made immediately when symptoms of hypocalcemia developed or 24 h postoperatively in symptom free patients and at day 5 postoperatively to evaluate late hypocalcemia.

Results: 120 patients who underwent total thyroidectomy in our clinic were included in this study. Values of PO₄³⁻ over 3.5 mg/dl was found to be the most sensitive parameter in predicting postoperative hypocalcemia with a rate of 59.09%. The specificity of this parameter was found to be 67.1%. The sensitivity and specificity of a measured iPTH value below 10 pg/ml was 29.55 and 92.11% respectively. The sensitivity and specificity of a measured value Ca levels <8 mg/dl was 18.18 and 94.74% respectively.

Conclusion: In light of our findings, we suggest that phosphate levels measured in the early postoperative phase of total thyroidectomy, can be used to predict the development of hypocalcemia. Phosphate measurement can be used as an alternative particularly in centers where iPTH measurement cannot be performed.