PS 11-28 ADRENAL INSUFFICIENCY UNDER STANDARD DOSAGE OF POST-OPERATIVE GLUCOCORTICOID REPLACEMENT AFTER HEMI-LATERAL ADRENALECTOMY FOR CUSHING'S SYNDROME

Abstract

Objective: The patients who have undergone hemi-lateral adrenalectomy for Cushing's syndrome become steroid-dependent. Therefore, sufficient replacement of glucocorticoid is needed in the post-operative period, though, determination of the adequate dosage for post-operative glucocorticoid replacement is difficult. Design and Method: A 62 year old Japanese woman presented hypertension 5 years ago and since then she showed loss of muscle strength and edematous face. Because facial edema, general fatigue, and muscle weakness were progressively worsened, she consulted us. Radiological examinations detected a 30 mm left adrenal mass. Endocrinological evaluations revealed an elevated urinary free cortisol (114 μg/day), without suppression of serum cortisol in midnight and with suppression of ACTH (<1.0 pg/ml) in the morning. After overnight 8 mg dexamethasone challenge, the serum cortisol level was maintained at 34.4 μg/dl and ACTH was <1.0 pg/ml. 131-IAdosterol scintigraphy revealed higher uptake in the left adrenal mass. Under a diagnosis of Cushing's syndrome due to left adrenal adenoma, laparoscopic left adrenalectomy was performed and 200 mg/day of hydrocortisone was administrated during peri-operative days. The dose was reduced gradually and she discharged with 30 mg/day of hydrocortisone. Results: She was transferred to emergency unit because of the symptoms of adrenal insufficiency on post-operative day 15. After an infusion of hydrocortisone 200 mg, the symptoms were immediately disappeared. The dose of hydrocortisone was slowly decreased under hospitalization; however, reduction of hydrocortisone lower than 60 mg/day was difficult because of nausea and fatigue. Hydrocortisone was gradually reduced and she discharged on post-operative day 92 at the dose of 30 mg/day. Conclusions: The glucocorticoid receptor would be down-regulated due to long-term exposure to excessive cortisol before surgery. Complicated heart failure was suggested to reduce absorption of hydrocortisone from intestine. In such cases, we should consider enough hydrocortisone administration with a dose of more than 30 mg/day to avoid adrenal insufficiency after surgery of Cushing's syndrome.