Endocrine Abstracts

Background/aims: The short synacthen test (SST) is a dynamic function test used to assess the hypothalamic pituitary adrenal axis. Interpretation requires consideration of sample timing and cortisol method. Currently the 30 minutes post-synacthen cortisol (CORT30) at NHS Greater Glasgow and Clyde (NHS GGC) is >450 nmol/l measured on the Abbott Architect. A large reference range study published a cut-off of >430 nmol/l for this method. This audit aims to document clinical outcomes of patients with results in the range 430–450 nmol/l.

Method: SST requests were identified from laboratory databases at NHS GGC for six months beginning 01/05/2017. Requests with CORT30 430–450 nmol/l were selected for further analysis to include reason for request, steroid status prior to test and outcome/clinical management of the patient post test.

Results: Tests with CORT30 430–450 nmol/l accounted for 3.4% requests (53/1573). Request reasons were varied and included: steroids for another condition (26%), pituitary tumour/lesion (11%), blood pressure (11%), adrenalectomy (9%), hypoglycaemia (9%) and lethargy (6%). Outcomes for patients prescribed oral steroids initially (n=18) were: steroids continued 29%; reduced dose 17%; steroid cover for illness 17%; steroids stopped 17%; relapse of primary condition requiring steroids 22%. Outcomes for patients not initially prescribed steroids (n=35) were: no steroids 71%; steroids started 8%; steroids for illness 8%; steroids for illness but since started 6%; steroids started but stopped soon afterwards 6%. Repeat SST was performed in 13 patients within 6 months of borderline test, 62% were normal. A further 4 patients had a repeat SST planned but not yet performed.

Conclusion: SSTs with results 430–450 nmol/l account for 3.4% of all requests. Repeat testing was performed or planned in 32% of these cases. Findings were reviewed by the endocrinology team and the 430 nmol/l cut-off has been implemented.