Early Postoperative Parathormone and Calcium as Prognostic Factors for Postoperative Hypocalcemia

Abstract

Background. Postoperative hypocalcemia is one of the most common complications after total thyroidectomy. Parathormone (PTH) and calcium levels, measured several hours after surgery, have been suggested as valuable markers for detecting patients at risk for post-thyroidectomy hypocalcemia. We aimed to determine if early post-surgery PTH and calcium levels can be used for the early identification of patients at risk for symptomatic hypocalcemia. Methods. PTH and calcium were measured before surgery and at 10 min and 4 h post-thyroidectomy, in 77 patients. Performance characteristics of PTH and calcium levels and their post/pre-surgery ratios were calculated. Results. Four-hour calcium was a sensitive (93.75%) but not specific (67.61%) indicator of patients at risk for symptomatic hypocalcemia. The 4-h/pre-surgery PTH ratio was the most accurate (90.81%) and the most specific (94.37%) test to identify patients at risk. Serum calcium at 4-h, 4-h/pre-surgery PTH ratio, and PTH at 10 min post-surgery had the higher diagnostic odds ratios (50.86, 32.85, and 29.04, respectively). The 4-h/pre-surgery PTH ratio also had the highest (0.694) Youden’s J statistic. Conclusions. Low serum calcium levels 4 h after thyroidectomy and the 4-h/pre-surgery PTH ratio could be valuable additions to everyday clinical practice in post-thyroidectomy patients.

Post-thyroidectomy hypocalcemia and related complications

“…According to Kim et al, (2021) and others, performing two PTH measurements (intraoperative and immediate postoperative), found that PTH values greater than 10.0 pg/ml and an increase in postoperative PTH compared to intraoperatively indicate low risk of hypocalcemia (Daskalaki et al, 2022;D. H. Kim et al, 2021;Rahman, 2021).…”

Construction and validation of a predictive model for hypocalcemia after parathyroidectomy in patients with secondary hyperparathyroidism

“…Hypocalcemia is one of the most common complications ( 6 ), with a prevalence of up to 20%–85% ( 7 , 8 ), and can result in convulsions, cardiac arrhythmias, seizures, and even sudden death in patients. The traditional causes of post-PTX hypocalcemia also includes severe vitamin D deficiency (uncorrected hypovitaminosis D) ( 9 ), the high frequency of dialysis ( 7 ), and the co-presence of malabsorption ( 10 ), etc. However, preoperative perioperative preparation may benefit patients more.…”