Endocrine Abstracts

Background: Peri-operative glucocorticoids are routinely administered to patients undergoing trans-sphenoidal surgery for non-functional pituitary adenomas (NFPA) irrespective of the integrity of hypothalamic-pituitary-adrenal (HPA) axis.

Aim: To evaluate HPA axis before and three months after endoscopic trans-sphenoidal adenomectomy (E-TSA) in patients with clinically NFPA utilizing 1 mg ACTH stimulation test and determine the need for glucocorticoid administration.

Design: Open prospective study.

Setting: Tertiary care referral hospital.

Patients: From July 1st, 2017 to December 31st, 2018, 63 consecutive patients (48 ± 12.5 years, M:F = 2.3:1) with intra/suprasellar non-functioning pituitary adenoma requiring surgical excision were enrolled in this study.

Interventions: Glucocorticoids were administered to patients with demonstrable hypocortisolism. Perioperative glucocorticoids were administered to patients with peak cortisol <16 µg/dl during 1 mg ACTH test preoperatively. Postoperatively, glucocorticoids were given to patients with 0800 cortisol <8 mg/dl on the third postoperative day. At three months follow up, glucocorticoids were given to patients with peak cortisol <16 µg/dl on LDACTH test. Main outcome measurements: Stimulated cortisol using low dose (1 mg) ACTH test (LDACTH) was determined preoperatively. After E-TSA, 0800 cortisol was determined on the third post-operative day and LDACTH test was repeated at three months after surgery.

Results: Hypocortisolism was present in 43 patients (68.2%) pre-operatively and persisted in 33 patients (52.4%) on the third post-operative day. Thirty-three patients (52.4%) had hypocortisolism at three months after surgery. Fourteen patients (22.2%) didn’t require glucocorticoids during the entire study period and thirty patients (47.6%) didn’t require glucocorticoids after three months. None of the patients developed adrenal crisis during the study. There was a significant correlation between postoperative day third 0800 cortisol ≥ 8 mg/dl and stimulated cortisol (LDACTH) ≥ 16 mg/dl at three months (r = 0.62, P < 0.0001). Postoperative day third 0800 cortisol <8 mg/dl had 75% sensitivity and 58.1% specificity in predicting adrenal insufficiency at three months after surgery (AUC 0.66, P = 0.026).

Conclusions: HPA function is preserved in significant proportion NFPA patients undergoing E-TSA. Perioperative glucocorticoids should be given only in patients with demonstrable preoperative hypocortisolism on 1 mg ACTH test. Postoperative day third 0800 cortisol <8 mg/dl is a reasonable predictor of adrenal insufficiency at three months after surgery.