Background: Short Synacthen tests (SSTs) are used to assess adrenal function by injecting tetracosactide and measuring blood cortisol after 30 and 60 min. Many SSTs at Royal Bournemouth Hospital (RBH) are undertaken externally to the Bournemouth Diabetes and Endocrine Centre (BDEC). There is an increasing cost-implication for undertaking SSTs exacerbated by recent problems with Synacthen supply. A 0900 h cortisol or random cortisol on acutely unwell patients can be sufficient for assessing adrenocortical function without the need for SSTs.
Method: We undertook a retrospective audit of 333 patients over 5 years that underwent SSTs at RBH. We assessed whether prior cortisol samples were undertaken (0900 h or random) and if a prior cortisol was >450 mmol/l, whether a SST was still undertaken. We also looked at whether non-BDEC patients were on steroids at time of testing.
Results: 55% (182/333) of SSTs were initiated external to the endocrine department. Only 50% of patients (169/333) had a prior cortisol measurement whether it was 0900 h or random. 20% (35/169) of these were >450 mmol/l and therefore could have avoided a SST. Of those without a prior cortisol the baseline cortisol was >450 mmol/l in 45% (75/164) and a SST could have been avoided. 19% (25/130) of non-BDEC patients were taking steroid therapy (steroid inhaler/nasal spray/kenalog injection) during the test and in many cases this was multiple different steroids.
Discussion: At RBH more than half of SSTs are undertaken by non-endocrinologists and many tests could potentially be avoided by undertaking a 0900 h cortisol. One in five of the tests performed outside the endocrine department were not initiated appropriately with patients being on steroids at time of testing. Discussing all future SSTs with BDEC could improve performance, reduce cost, and prevent unnecessary testing.