Endocrine Abstracts

Temporary hypocalcaemia following total thyroidectomy occurs in around 30% of patients and is usually due to inadvertent damage to the parathyroid glands. Whilst mild cases are easily managed with oral calcium supplementation, there is the potential for severe calcium deficit with the ensuing risks of cardiac dysrhythmias, tetany and in extreme cases death. It is common practice to have a post-surgery protocol to allow the early identification of these patients. Whilst many protocols rely solely on post-operative serum calcium levels, more are now utilising parathyroid hormone (PTH) assays to predict those at risk of developing hypocalcaemia. In most of these centres, it is possible to have a PTH result within hours of the request. Unfortunately, in many UK hospitals, laboratories will not process PTH assays overnight or indeed daily. For this reason there is no widely accepted protocol, which incorporates the test, despite the growing body of evidence supporting its use.

Our unit is a tertiary referral centre performing around 100 thyroid operations per year. Within our multidisciplinary clinic we have an ongoing prospective database of 1483 patients who have undergone thyroid surgery over the last 15 years. Of the 505 patients who underwent total thyroidectomy, 22.2% developed temporary hypocalcaemia. Based on our experience and the latest evidence, we have produced a protocol to allow the prompt identification and management of this complication. It has the advantage over other protocols in that it allows for a lack of overnight laboratory availability without compromising patient safety. We also propose that it is possible to accurately identify patients who will not suffer hypoparathyroidism allowing their safe and early discharge. To date we have tested the protocol on 31 consecutive patients undergoing total or completion thyroidectomy (eight of whom developed temporary hypocalcaemia), demonstrating its efficacy and reliability in a clinical setting.