Pituitary-adrenal dynamics after ACTH-secreting pituitary tumor resection in patients receiving no steroids post-operatively

Abstract

It has recently been suggested that the classical routine of glucocorticoid administration before and after transsphenoidal surgery (TSS) in Cushing's disease (CD) patients may not be necessary, since it is likely that peritumoral normal corticotrophs are not completely suppressed during this period. We compared the dynamics of ACTH and cortisol from a group of CD patients (cured and not cured), receiving no steroids post-operatively, with a control group of acromegalic patients who presented normal hypothalamic-pituitary-adrenal (HPA) axis. Blood samples for ACTH and cortisol determination were obtained immediately before, at the end of surgery and at 4, 8, 12, 16, 24, 48 and 72 h after surgery, in 8 cured CD patients (Group I), 9 not cured CD patients (Group II) and in 7 subjects with acromegaly (Group III) who presented normal HPA axis (control group). The mean ACTH level in Group I was significantly lower than in Group III from 4 to 12 h and lower than in Group II from 8 to 12 h post-operatively. The mean cortisol level in Group I was lower than in Groups II and III from 8 to 72 h after surgery. No difference in mean cortisol level was observed among Groups II and III during the evaluated period. The lowest cortisol value in Group II was 193 nmol/l (at 24 h after surgery) and in Group I patients, after 20 h post-operatively, the highest cortisol level was 165 nmol/l. Although all cured CD patients (Group I) presented serum cortisol level lower than 55 nmol/l until 72 h after surgery, none had significant complications related to adrenal insufficiency. Ours findings are in agreement with recent observations that there is probably no need for glucocorticoid administration until clinical and/or laboratorial data are suggestive of adrenal insufficiency. However, we have also shown that a subphysiological HPA axis response could be observed in cured CD patients after TSS, and a definitive conclusion about glucocorticoid management during and after this procedure could not be made on the ground of the few cases studied in the literature.