Endocrine Abstracts

Introduction: The demand of cortisol rises during stress and to avoid acute cortisol deficiency, patients undergoing transsphenoidal surgery at Skåne University Hospital (Sweden) receive peri- and postoperative substitution with hydrocortisone (HC), even at normal ACTH function. Some anesthetics are known to affect cortisol levels.

This study aimed to assess the perioperative cortisol plasma levels during transsphenoidal surgery in ACTH sufficient and deficient patients.

Description of methods/design: We studied 15 patients with transsphenoidal surgery for a pituitary adenoma. Out of 10 patients with normal ACTH function (morning P-cortisol >400 nmol/l and/or >550 nmol/l after Synacthen); 7 patients were not receiving HC substitution whereas the remaining 3 received the routine 50 mg iv HC. 5 patients with ACTH deficiency received the routine iv HC of 100 mg in the morning before surgery and with the additional 50 mg HC for an afternoon operation (n=2). P-cortisol was measured at the start and every 30 min during surgery (surgery duration 60–200 min). Propofol and remifentanil were used as anesthetics.

Results: Among 7 patients with normal ACTH function, P-cortisol levels were, at the start of surgery between 38–244 nmol/l and during the operation the levels decreased to 24–139 nmol/l. At the time point of intrasellar manipulation a distinct rise of the cortisol levels was noted in 6 of these 7 patients (to 350–628 nmol/l). Correspondingly, in the 3 ACTH-sufficient patients receiving 50 mg HC at the start of surgery, cortisol levels increased slightly, from 407 to 553, 719 to 822, and 1092 to 1180 nmol/l, respectively. In the 3 ACTH-deficient patients undergoing surgery in the morning cortisol levels fell slightly from very high levels. In the 2 patients who received additional 50 mg HC in the afternoon cortisol levels peaked at 1914 and 2384 nmol/l.

Conclusion: The low p-cortisol in the first phase of surgery in ACTH-sufficient patients without HC substitution is probably explained by anesthetics. When surgery reached the sella tursica, cortisol levels increased in 6 of 7 patients. In the ACTH deficient patients, pre-operative HC resulted in high cortisol levels without corresponding increase after intrasellar manipulation. Patients who did not receive HC substitution did not show any abnormal parameters during surgery. Supraphysiological cortisol levels were achieved after iv HC.