The Study of a Safe and Cost-effective Method to Identify Patients at Low Risk for the Development of Significant Hypocalcemia After Total Thyroidectomy.

INTRODUCTION:

In recent years there has been a global trend towards more radical and aggressive approach to thyroid surgery (total or subtotal thyroidectomy against semithyreoeidectomy), almost regardless of the pathological cause, even for benign diseases. There is also developed, a serious skepticism as complications of total or subtotal thyroidectomy is neither rare nor insignificant. In particular, complications of thyroidectomy is the laryngeal nerve paresis (0.2% bilateral, unilateral 3,7-3,9%, 2% transient, lasting 1%), bleeding (1-2%), infection of the wound (0, 3-1,6%) and hypocalcaemia (permanent hypocalcaemia in over 6 months follow up 1,7-4,4%, while transient, manageable with vit D and calcium substitution 8,3-9,9%). The post total thyroidectomy hypocalcaemia is not only more frequent but also has the most delayed onset after surgery (up to several 24hours later) in relation to bleeding and paresis of the laryngeal nerve, which is immediate postoperative complications. This is the main cause of prolonged hospitalization and monitoring of patients postoperatively which is linked to increased risk of bacterial infections and increased cost.9, 10 Great effort has been made in the last 15 years to reduce the length hospital stay of patients in order to perform the total thyroidectomy as a one day surgery.6, 11 In this way great importance is the prediction of those patients are more likely to experience post-operative hypocalcaemia. The appearance of postoperative hypocalcaemia associated with specific diseases such as thyroid disease Graves, the thyreotoxicosis and thyroid cancer 7.8, and the surgical technique (the extent of excision, the type of thyroid artery ligation, the number of parathyroid recognized intraoperative but also those autotransplanted) 12. Moreover, beyond these factors, great importance is given to methods of monitoring patients to find reliable indicators to allow safe release out of the hospital after the first 24 hours without risk of hypocalcaemia. The measurement of parathyroid hormone (PTH) both intraoperative and postoperatively (4 hours) is a hot topic in contemporary literature and promises accurate predictions 13, but there is disagreement about the precise time of receiving the specimens and great consideration about the increased cost 14, 15 (at our hospital is not even available). An older, simple, fast and economical method is to measure levels of free serum calcium 6,9. Despite that the correlation of the immediate post-operative levels of free calcium, with the likelihood of developing hypocalcaemia has variations in different surveys, resulting to early release of patients directly when free calcium is in normal range, by some departments, while others follow strict protocols of monitoring patients for days . However, the variation in the levels of free serum calcium between the first 6 and 12 postoperative hours alone or in combination with measurement of PTH seems to give some answers and it is under great consideration in the international community.

It is therefore, in line with the current literature, important to develop a safe, and also cost-effective protocol monitoring patients after total thyroidectomy, which, in combination with predisposing risk factors of hypocalcaemia, will predict low-risk patients for developing hypocalcaemia and allow secure release from the hospital.

PRIMARY OBJECTIVES:

The objective of this perspective study is to correlate the variability of the levels of free serum calcium (Ca + +), and also the levels of albumin (ALB), phosphorus (PO-3), magnesium (Mg) and total albumin (TPR), between two measurements on 6 and 12 hours postoperatively, the incidence of hypocalcaemia in patients undergoing total thyroidectomy for any reason. The aim is to develop on the basis of variation in levels of free serum calcium, a secure method of prediction and identification of low risk patients for developing hypocalcaemia providing an early release from hospital.