Endocrine Abstracts

Introduction: Patients undergoing total thyroidectomy may stay in hospital for several days postoperatively because of the risk of hypocalcaemia, which necessitates frequent serum calcium level checks. A reliable test for predicting postoperative hypocalcaemia may enable many patients to have day case surgery. Recent studies suggest that perioperative PTH levels may be useful in identifying those at risk of hypocalcaemia.

Objectives: The aim of the study was to establish whether intra and perioperative PTH levels could predict the occurrence of postoperative hypocalcaemia in patients undergoing total thyroidectomy.

Methods: The study was carried out prospectively from January 2005 to March 2006. All patients undergoing total thyroidectomy were eligible for entry into the study. Venous blood samples for PTH and serum calcium assay were taken preoperatively, post-induction, post-excision of the thyroid, 6 hours postoperatively and 20 hours postoperatively. The end point was hypocalcaemia (corrected calcium <2.20 mmol/L) within 48 hours of surgery.

Results: 22 patients were eligible and results were available for 20 patients, with every patient having a 6 hour postoperative calcium and PTH level available. 10 out of 20 patients (50%) developed hypocalcaemia of <2.20 mmol/L within 48 hours of surgery. 6 patients (30%) had a PTH level 6 hours postoperatively of <1 pmol/L of whom 3 (15%) had hypocalcaemia that definitely required treatment. 4 patients (20%) with a postoperative PTH level of >1 pmol/L developed hypocalcaemia and in all cases this was mild and transient. No patient with a 6 hour postoperative PTH level of >1 pmol/L required treatment for hypocalcaemia.

Conclusions: Perioperative PTH levels may be useful in predicting postoperative hypocalcaemia following total thyroidectomy. Consequently, changes in service provision from an inpatient basis to a day case unit with the facility to admit patients could reasonably be considered with the aim of saving money and beds whilst improving patient care.