Endocrine Abstracts

Etomidate, an imidazole derived anaesthetic agent, potently inhibits adrenocortical 11-beta-hydroxylase at non-hypnotic doses in Cushing's syndrome. We report its use in controlling hypercortisolism in a patient with aggressive Cushing's disease requiring pelvic surgery for endometrial carcinoma.

IJ, a 42-year old female was diagnosed with Cushing's disease in 1998 in Malaysia. 8am cortisol was 800nmol/l, midnight cortisol 659nmol/l and ACTH 103ng/l. MRI revealed a 14x16x19mm pituitary adenoma. In May 1999 she had sub-frontal craniotomy with sub-capsular excision of the tumour; post-operative 8am cortisol was 531nmol/l.

Transverse colectomy was performed in 2001 for Dukes B adenocarcinoma of the colon.

MRI pituitary showed suprasellar and right cavernous sinus extension. She presented to our unit for further management in September 2001. Mean cortisol was 765nmol/l and ACTH 95ng/l on metyrapone. She underwent trans-sphenoidal surgery and external beam radiotherapy (45Gy fractionated over 7 weeks). 9am cortisol was 500nmol/l; she was commenced on metyrapone 1g tds and ketoconazole 200mg tds. Mitotane was not tolerated due to adverse side effects. Stereotactic multi arc radiotherapy (12.5Gy) was performed in January 2003 and transcranial debulking surgery in March 2004. Mean post-operative cortisol was 908nmol/l and ACTH 464ng/l.

In July 2004 she was diagnosed with endometrial carcinoma and total abdominal hysterectomy was planned. Mean cortisol was 928nmol/l and she was commenced on rosiglitazone without effect (mean cortisol 1226nmol/l). Pre-operatively she commenced an etomidate infusion (2.5mg/hr). Mean cortisol fell to 288nmol/l, reaching a nadir of 172nmol/l on day 3 and she commenced hydrocortisone 5mg tds. The etomidate infusion was continued post-operatively; she made an uncomplicated recovery.

This case highlights the value of intravenous etomidate in the acute control of hypercortisolism where conventional treatments are inadequate or poorly tolerated.