Intact PTH measurement 1 hour after total thyroidectomy as a predictor for patients at risk for developing symptomatic hypocalcaemia

Abstract

Postoperative hypocalcaemia is one of the most common complication observed in patients undergoing total thyroidectomy with a report incidence ranging from 1.6% to 50%. Transient hypocalcaemia occur in upto 50% patients and permanent hypocalcaemia in 2%.Symptoms appear usually between 2 ^nd to 5 ^th postoperative day. In the absence of any reliable predictors of clinically relevant hypocalcaemia after total thyroidectomy, prolonged hospitalization to monitor serum calcium concentrations has been considered the standard of cure. To minimize postoperative complications and to permit an early and safe discharge, it is important to identify various methods to predict patients at high risk of developing significant hypocalcaemia , who are candidates for early treatment and patient at low risk who can be discharged early from hospital. We reviewed our experience in Yenepoya Medical College with 22 total thyroidectomies to determine the threshold value of 1 hour post total thyroidectomy iPTH level that can identify those at high risk for developing symptomatic hypocalcaemia. This is a prospective study done from sept 2012 to sept 2013.Based on our observations we concluded that, a 1 hour postoperative serum intact PTH 15pg/l has both sensitivity and specificity >90% for predicting patients at risk for developing post total thyroidectomy symptomatic hypocalcaemia.