RESUMO
Background: We aimed to assess the predictive value of the absolute and relative intact parathormone (iPTH) decline levels as reliable markers of postoperative hypocalcemia. Materials & methods: iPTH levels were measured 4 h after surgery and the following morning after surgery (postoperative day 1). iPTH, absolute iPTH decline (ΔPTH) and relative iPTH decline (ΔPTH%) were calculated and correlated with symptomatic hypocalcemia. Results: Of the 95 patients, 20% of patients (n = 19) developed symptomatic hypocalcemia. The ΔPTH (U = 206; p < 0.001) and ΔPTH% (U = 127; p < 0.001) were significantly higher in patients with symptomatic hypocalcemia. A ΔPTH% of 20% (sensitivity of 84%; specificity of 91%); and an absolute iPTH decline of 3.75 pg/ml (sensitivity of 74%; specificity of 87%) were highly predictive of symptomatic hypocalcemia. Conclusion: Postoperative ΔPTH and ΔPTH% have the potential to be predictors of symptomatic hypocalcemia following thyroidectomy and could facilitate a safe early discharge.