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The value of short synacthen testing in patients treated with corticosteroids: an audit at a teaching hospital
May Al-Shaghana, Peter Hewins,Sarah Logan
Renal Medicine Department, Queen Elizabeth Hospital, Birmingham
Problem
Long-term corticosteroid therapy is frequently used in renal patients with immune-mediated glomerular disease. Where feasible this medication can be withdrawn for patients in stable remission, thereby reducing the risks and complications associated with extended corticosteroid treatment. However unrecognised adrenal insufficiency may be present and thereforestopping steroids could be potentially life threateningin this patient cohort.
Over the past couple of years the renal department in this tertiary centre has changed its clinical practice and routinely undertaken short synacthen tests (SST)prior to stopping long-term corticosteroids; previouslyadrenal function was only tested when patients became overtly unwell after the withdrawal ofcorticosteroid treatment.
Purpose
Toidentify the prevalence of adrenal insufficiency in patients who have had an SST prior to stopping steroids in order to establish whether it is valuable to test asymptomatic patients to allow for improved management of patients who are found to have adrenal insufficiency.
Design
Patients who had an SST conducted between 1st September 2013 and 31st August 2014 were studied. Data was collected through a case note review using online electronic systems.
Findings
41 (21 males and 20 females) SSTs were conducted on patientswho were on long-term immunosuppression for various indications; glomerulonephritis (17/41), lupus nephritis (10/41), ANCA associated vasculitis (6/41) and other underlying diagnoses such as tubulo-interstitial nephritis (8/41). Patients were on corticosteroids for an average of 7 years prior to having the SST (range: 0-17). At the time of testing mostpatients (24/41) were on prednisolone 5mg daily. Forty-six percent (19/41) of patients failed the SST; a fail was defined as the post-test cortisol<550nmol/l. The average 30-minute post-test cortisol level was 721nmol/l (range: 555-997) for the patients who passed the test and 384nmol/l (range: 70-522) for the patients who failed.
8/19 patients who failed the SST were started on hydrocortisone replacement therapy and 11/19 remained on prednisolone.5/19 patients who failed the SST were referred to endocrinology for further management. 4/19 of the patients who failed the SST had a repeat test after an average of 31 weeks (range: 9-48 weeks), the other 15 patients did not have a repeat test during the duration of this study.One patient passed the repeat SST and came off steroids, the other 3 patients who failed the retestremained on their steroid treatment.
Of the 22 patients that passed the SST, 16 patients stopped steroids altogether.
Conclusion
Approximately half of patients on long term corticosteroids were shown tohave adrenal insufficiency. Whilst all patients who were found to have adrenal insufficiency were either commenced on hydrocortisone therapy or maintained on prednisolone, only one quarter of these patients were referred to endocrinology for appropriate long term management and follow up.
Relevance
Due to the high prevalence of adrenal insufficiency in this cohort, local practice was adjusted to routinely conduct an SST prior to withdrawing steroids in patients who have been on long term corticosteroid therapy. This facilitated safe management. The audit also highlighted the need for more frequent conversion to hydrocortisone and systematic repeat testing.