THE IMPORTANCE OF CORTISOL AND ACTH IN TH E IMMEDIATE POSTOPERATIVE PERIOD OF PITUITARY SURGERY IN NONSECRETORY ACTH ADENOMAS

BACKGROUND: The aim of this study was to evaluate the usefulness of ba sal cortisol and ACTH in the immediate postoperative period of pituita ry surgery as indicators of definitive adrenocorticotropin function. M ETHODS: Twenty-one patients with pituitary, non producers of ACTH, ade nomas, three microadenomas and 18 macroadenomas treated by adenomectom y by a trans-sphenoidal route were respectively studied. The basal cor tisol and ACTH were compared in the first week following surgery with the definitive results obtained after one month by dynamic tests (stim ulation with ACTH or insulin hypoglucemia). RESULTS: The six patients with secondary adrenal failure (AF) in the definitive evaluation had l ower basal cortisol in the immediate postoperative period than the pat ients with AF (135.3 +/- 225.3 nmol/l versus 473.6 +/- 147.2 nmol/l; p < 0.05). The values of ACTH were also lower (2.3 +/- 1.6 nmol/l versu s 4.8 +/- 3.4; p < 0.05). In all the patients with definitive AF excep t one, the basal cortisol in the first week was lower than 130 nmol/l and in those who did not present AF it was greater than 220 nmol/l. CO NCLUSIONS: In the immediate postoperative period after pituitary surge ry cortisol is a good indicator of definitive adrenocorticotropin func tion. This parameter may identify the patients requiring posterior sub stitutive treatment.