Perioperative serum cortisol levels in ACTH sufficient and ACTH deficient patients during transsphenoidal surgery of pituitary adenoma

Purpose No previous study has analyzed serum cortisol levels during transsphenoidal endoscopic pituitary surgery in patients with and without hydrocortisone (HC) substitution. Methods A total of 15 patients undergoing surgery for a pituitary adenoma were studied. Those with normal ACTH function were either not given HC (n = 7) or received 50 mg intravenous HC at the start of surgery (n = 4). Patients with ACTH deficiency received intravenous HC of 100 mg in the morning before surgery (n = 4) with the additional 50 mg for an afternoon operation (n = 2). Propofol and remifentanil were used as anesthetics. Serum cortisol was measured at the start of and every 30 min during surgery. Results Among 7 patients with normal ACTH function without HC substitution, cortisol levels before surgery were 126–244 nmol/L, among the 4 patients undergoing surgery in the morning, whereas the 3 who underwent surgery in the afternoon had lower levels, 38–76 nmol/L. During nose/sinus surgery cortisol levels decreased to 79–139 and 24–54 nmol/L, respectively. At intrasellar manipulation a distinct rise was noted. Also, in the 4 ACTH sufficient patients receiving HC, cortisol levels decreased during nose/sinus surgery, but only with a slight increase during intrasellar surgery. In the 4 ACTH deficient patients cortisol peaked at 1914–2582 nmol/L. Conclusions Patients with normal ACTH function without HC substitution had very low cortisol levels during the first part of surgery, likely suppressed by the anesthetics. After mechanical impact in the sella, a marked increase in cortisol was noted. Supraphysiological cortisol levels were achieved with our routine HC substitution, advising us to reduce the supplementation.