Validation of intra-operative parathyroid hormone and its decline as early predictors of hypoparathyroidism after total thyroidectomy: A prospective cohort study

• Hypoparathyroidism is a common complication after total thyroidectomy.
• Early and accurate predictor of hypoparathyroidism is always sought.
• ioPTH and PTH decline are accurate, reliable, and early predictor of post-operative hypoparathyroidism.

IntroductionTotal thyroidectomy is a preferred surgical technique for benign as well as malignant thyroid pathologies, but many a times can cause hypoparathyroidism. The aim of this study is to evaluate the intra-operative parathyroid hormone (ioPTH) level and its decline as predictors for post-operative hypoparathyroidism after total thyroidectomy.MethodsIn this single-centre prospective cohort study, 90 patients who underwent total thyroidectomy for benign as well as malignant pathologies of thyroid gland were studied. Intra-operative parathyroid levels and at different time intervals parathyroid hormone and serum calcium levels were measured to predict hypoparathyroidism. The data was analysed using independent sample t test and p value < .05 was considered to be significant.ResultsThere were 14 male and 76 female patients with a mean age of 41 years. Most common thyroid pathology for which total thyroidectomy was done was colloid goitre (62). Twenty four patients (26.66%) developed hypoparathyroidism. Intra-operative PTH was found to be most accurate predictor for diagnosing post-operative hypoparathyroidism (cut off was (11.3 pg/ml, calculated using ROC curves) and has maximum sum of sensitivity (91.7%) and specificity (97%). On taking cut off values of intra-operative PTH and PTH decline together, they were found to be most accurate predictor for permanent hypoparathyroidism.DiscussionEarly and accurate predictor of hypoparathyroidism is very important and always sought. Very early prediction during intra-operative periods can be used for auto transplantation of parathyroid gland.ConclusionIntra-operative parathyroid hormone and its decline are accurate, reliable, and early predictor of hypoparathyroidism after total thyroidectomy.