title: Use of day 1 early morning cortisol to predict the need for glucocorticoid replacement after pituitary surgery.
abstract: BACKGROUND
  Assessment of adrenal reserve in patients who have undergone pituitary surgery is crucial. However, there is no clear consensus with regards to the type and timing of the test that should be used in the immediate post-operative period. Recently, there has been increased interest in measuring post-operative cortisol levels. We present our data utilising day 1 post-operative early morning cortisol as a tool to assess adrenal reserve in steroid-naive patients.
  
  
  METHODS
  A retrospective analysis of endoscopic pituitary surgery undertaken over a 2-year period. 82 patients underwent 84 surgeries in total. Patients who were already on glucocorticoids pre-operatively and patients with Cushing's disease, pituitary apoplexy and those without follow-up data were excluded, leaving a study group of 44 patients with 45 operations. A 9am day 1 post-operative cortisol value of > 400 nmol/L was taken as an indicator of adequate adrenal reserve. All the patients were reassessed at 6 weeks with a standard short synacthen test (SST) using 250 micrograms of intravenous synacthen.
  
  
  RESULTS
  22 out of 45 patients had a cortisol value of > 400 nmol/L on day 1 post-operatively and were discharged without glucocorticoid supplementation. Of these, only 2 patients subsequently failed the SST when reassessed at 6-8 weeks. The remaining 23 patients had a cortisol value of < 400 nmol/L on day 1 post-operatively and were discharged on hydrocortisone 10 mg twice daily. At 6-8 weeks, nine continued to show suboptimal stimulated cortisol levels whereas the remaining fourteen patients showed adequate adrenal reserve. The 9 am cortisol value had high specificity (81.8%) and positive predictive value (90.9%) for integrity of the HPA axis. Sensitivity was 58.8% and negative predictive value was 39.1%.
  
  
  CONCLUSIONS
  A day 1 post-operative early morning cortisol is a useful tool to predict adrenal reserve post-pituitary surgery, enabling clinicians to avoid unnecessary blanket glucocorticoid replacement.
authors: a Department of Endocrinology , University Hospital of Wales , Cardiff , UK.
authors: L N Rao
authors: LN
authors: Bondugulapati
authors: b Institute of Molecular and Experimental Medicine, Cardiff University , Cardiff , UK.
authors: Christopher
authors: C
authors: Campbell
authors: a Department of Endocrinology , University Hospital of Wales , Cardiff , UK.
authors: Sharmistha Roy
authors: SR
authors: Chowdhury
authors: c Department of Neurosurgery , University Hospital of Wales , Cardiff , UK.
authors: Pablo
authors: P
authors: Goetz
authors: a Department of Endocrinology , University Hospital of Wales , Cardiff , UK.
authors: J Stephen
authors: JS
authors: Davies
authors: a Department of Endocrinology , University Hospital of Wales , Cardiff , UK.|b Institute of Molecular and Experimental Medicine, Cardiff University , Cardiff , UK.
authors: D Aled
authors: DA
authors: Rees
authors: c Department of Neurosurgery , University Hospital of Wales , Cardiff , UK.
authors: Caroline
authors: C
authors: Hayhurst
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood* / Q000378:metabolism; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010900:Pituitary Diseases / Q000175:diagnosis / Q000601:surgery*; D010913:Pituitary-Adrenal System / Q000378:metabolism; D011182:Postoperative Care; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D005938:Glucocorticoids; D006854:Hydrocortisone
keywords: Pituitary adenoma; corticosteroids; hypothalamo-pituitary-adrenal axis; short synacthen test; transsphenoidal surgery