Endocrine Abstracts

A 26-year-old woman presented to the Endocrine clinic with features of Cushing’s syndrome (CS). Investigations revealed a non-suppressible cortisol in low dose Dexamethasone suppression test with a suppressed ACTH, and two positive 24-hour urine cortisol collections, indicating CS. CT imaging revealed a left adrenal adenoma of 3.4 cm. Following a left adrenalectomy, she was discharged on once daily Prednisolone 3 mg. She was well for a year except for one occasion where she reported forgetting to take her Prednisolone and started vomiting. She did not seek medical help. This resolved after she had her Prednisolone dose the following day. On review a year later, a Short Synacthen test (SST), showed a suboptimal response (Table 1). As we were certain that the right adrenal was intact, we planned to gradually reduce the prednisolone dose, to assess for recovery of endogenous cortisol production. Administering a replacement dose of glucocorticoids during the perioperative period helps to preserve normal physiological function, while also reducing potential risks of adrenal crisis. While corticosteroid therapy is commonly used for patients with CS undergoing adrenalectomy, there is no clear consensus on the best approach. A general strategy involves administering steroids both intraoperatively and postoperatively, starting with intravenous administration followed by oral administration, and then gradually tapering the dosage to allow recovery of the HPA axis and endogenous cortisol production. There is limited evidence how best to do this. We have found use of a Prednisolone tapering regimen alongside clinical assessment can help the weaning process. She is currently being weaned down to 1 mg Prednisolone. Patients with adrenal CS have reduced cortisol secretion due to negative feedback on the HPA axis. This leads to a decrease in ACTH release. Reduced ACTH stimulation to both the adrenal cortex surrounding the lesion and the contralateral, often atrophic adrenal gland, results in adrenal insufficiency and need for glucocorticoid replacement therapy. However, patients undergoing unilateral adrenalectomy will have adrenal reserve in the contralateral adrenal gland and should be able to recover endogenous cortisol production. This can be stimulated by deliberately reducing the dose of prednisolone to aid ACTH secretion. Life-long glucocorticoid replacement therapy may be avoided in such patients.