Evaluation of the hypothalamic-pituitary-adrenal axis immediately after pituitary adenomectomy: is perioperative steroid therapy necessary?

Patients undergoing pituitary adenomectomy are usually given glucocorticoid therapy, although there are no data to document the need for such therapy. We prospectively studied hypothalamic-pituitary-adrenal axis (HPA) function in 88 consecutive pituitary adenoma patients before and after selective adenomectomy, excluding those with corticotroph adenomas. Preoperatively, 5 patients had adrenal insufficiency (AI); they were treated with glucocorticoids and excluded from the analysis. The remaining 83 patients had normal HPA function preoperatively and were not given glucocorticoids before, during, or immediately after surgery, but were closely monitored, and their serum cortisol levels were measured in the immediate postoperative period. Two patients were clinically suspected to have AI postoperatively and were treated accordingly. The remaining 81 patients had no clinical manifestations of AI and received no glucocorticoid therapy. Their serum cortisol levels in the immediate postoperative period were appropriately elevated. The mean serum cortisol level was 40.5 +/- 11.1 (+/- SD) micrograms/dL (1117 +/- 306 nmol/L) 6 h after surgery; serum cortisol levels decreased gradually thereafter. Morning serum cortisol levels were within the normal range on the fourth, fifth, and sixth days after surgery: day 4, 15.1 +/- 7.0 micrograms/dL (417 +/- 193 nmol/L); day 5, 16.4 +/- 5.6 micrograms/dL (453 +/- 155 nmol/L); and day 6, 16.3 +/- 5.7 micrograms/dL (450 +/- 157 nmol/L). When tested 3 months after surgery, all 81 patients had normal HPA function. We conclude that HPA function is rarely compromised after selective pituitary adenomectomy. Close observation and serum cortisol measurements in the immediate postoperative period can reliably predict the integrity of the HPA after surgery. Routine glucocorticoid therapy is not needed in patients undergoing selective adenomectomy whose preoperative adrenal function is normal.