Vol. 7, Issue 2, Part B (2025)

Background: Postoperative hypocalcaemia is the most common complication following total thyroidectomy, often caused by transient or permanent hypoparathyroidism due to inadvertent parathyroid gland damage. Early identification of patients at risk allows timely calcium supplementation and may facilitate early discharge.
Objective: To find out the prediction of post-operative hypocalcaemia by early PTH assay among the patients undergone total thyroidectomy in DMCH. 
Methods: This prospective observational study was conducted at the Department of ENT & Head-Neck Surgery, Dhaka Medical College Hospital (DMCH). Eighty patients undergoing total thyroidectomy were included. Serum intact PTH was measured within one hour postoperatively, and calcium levels were assessed preoperatively, 24, and 48 hours postoperatively. The association between PTH levels and hypocalcaemia was analyzed, and sensitivity, specificity, predictive values, and accuracy were calculated.
Results: The mean age of patients was 41.4±13.96 years with ranged from 18 to 80 years and out of 80 samples male were 7(8.8%) and female were 73(91.2%) with a male to female was 1:10.5. Almost two third (61.3%) of cases were benign and 31(38.8%) malignant. More than one third (38.8%) of patients had ipsilateral enlarged cervical lymph nodes and needed neck dissection. The mean preoperative PTH level was 39.51±21.81 pg/mL, which significantly declined to 16.12±16.34 pg/mL postoperatively (p=0.001). Hypocalcaemia developed in 42.5% of patients at 24 hours and 48 hours postoperatively. Postoperative PTH levels showed significant correlation with hypocalcaemia at 24 hours (p=0.001) and 48 hours (p=0.001). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of first-hour PTH for predicting hypocalcaemia were 88.9%, 100%, 100%, 89.3%, and 94.2%, respectively.
Conclusion: First hour post-operative Parathyroid hormone assay is more effective to predict early post-operative hypocalcaemia after total thyroidectomy.