The Short Synacthen Test (SST) is a widely used investigation of adrenocortical function and is considered the gold standard for diagnosing primary adrenal insufficiency (PAI) by the Endocrine Society1. The standard high-dose test involves administration of a supraphysiological dose (250mcg) of synthetic adrenocorticotropic hormone (ACTH), followed by serial measurement of plasma cortisol. The SST protocol can be time consuming and labour intensive to perform and not without risk, with anaphylaxis to Synacthen previously reported2.
With the development of the modern ACTH assay, guidelines for investigating PAI have shifted to recommend paired measurement of serum cortisol and plasma ACTH initially, with progression to SST only in equivocal cases1. Other indications include evaluation of adrenal suppression after exogenous steroid use, suspected 21-hydroxylase deficiency and other causes of adrenal hyperplasia.
The SST remains frequently requested in public hospitals within Queensland and is also one of the only dynamic tests of endocrine function requested by non-endocrinologists. Our clinical experience suggests that the SST is not always performed for a generally accepted indication or in the appropriate clinical setting.
Our retrospective audit therefore seeks to evaluate SST requesting patterns across public hospitals in Queensland, using data collected by Pathology Queensland between January 2020 to January 2021. The electronic medical record of these patients will be accessed to determine the indication for the test, as well as which specialty requested the test, and whether there were documented SST-related adverse events. Our primary objective is to determine the reasons for performing SSTs within Queensland public hospitals and to compare this with existing recommendations.