Objectiva: Postoperative intact parathyroid hormone (iPTH) levels and some other factors as a predictor of hypocalcemia are analyzed in 115 patients after TTE.
Background: Postoperative hypocalcemia is the most common complication observed after total thyroidectomy (TTE). It is not easy to predict in which patients this complication will occur. We adopted and implemented a novel method to predict this complication – monitoring of postoperative intact parathyroid hormone (iPTH) levels.
Methods and results: Prospective study involves 115 patients. From January till December 2010 we performed 111 TTE and 4 completion thyreoidectomies (hemithyreoidectomy (HTE) after previous HTE). Gender and age of patients, final histopatology diagnosis, number of parathyroid glands visible during operation, duration of operation and surgeon were factors that did not influence development of postoperative hypocalcemia. A hospital stay was prolonged in patients with hypocalcemia. iPTH level morning after surgery less than 15 pg/ml was a statistically significant predictor of postoperative hypocalcemia.
Sensitivity, specificity, positive and negative predictive value of iPTH<15 pg/ml for predicting postoperative hypocalcemia were 71 %, 99 %, 97 % and 86 %, respectively.
Sensitivity of iPTH<15 pg/ml in predicting symptomatic postoperative hypocalcemia was 100 %.
Conclusion: Measuring iPTH levels morning after TTE allows prediction of subsequent hypocalcemia with a high sensitivity, specificity, PPV and NPV. Normal iPTH levels ruled out development of hypocalcemia symptoms. Patients with normal iPTH can be safely discharged and the overtreatment of postthyroidectomy patients with calcium and/or vitamin D supplements can be also avoided (Tab. 2, Fig. 3, Ref. 29).