[Value of basal cortisol and ACTH in the immediate postoperative period of hypophyseal surgery in non-ACTH secretory adenomas].

BACKGROUND: The aim of this study was to evaluate the usefulness of basal cortisol and ACTH in the immediate postoperative period of pituitary surgery as indicators of definitive adrenocorticotropin function. METHODS: Twenty-one patients with pituitary, non producers of ACTH, adenomas, three microadenomas and 18 macroadenomas treated by adenomectomy by a trans-sphenoidal route were respectively studied. The basal cortisol and ACTH were compared in the first week following surgery with the definitive results obtained after one month by dynamic tests (stimulation with ACTH or insulin hypoglycemia). RESULTS: The six patients with secondary adrenal failure (AF) in the definitive evaluation had lower basal cortisol in the immediate postoperative period than the patients 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 versus 4.8 +/- 3.4; p < 0.05). In all the patients with definitive AF except 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. CONCLUSIONS: In the immediate postoperative period after pituitary surgery cortisol is a good indicator of definitive adrenocorticotropin function. This parameter may identify the patients requiring posterior substitutive treatment.