gms | German Medical Science

Objective: After transsphenoidal pituitary surgery postoperative hydrocortisone substitution is usually conducted. There are no guidelines for the postoperative hormone substitution. This study is exploring the predictive value of the fasting cortisol level (FCL) on 6th postoperative day (POD6) for the recovery of the adrenocorticotropic axis in order to facilitate the handling of hydrocortisone substitution.

Methods: Retrospectively the data of 286 patients who underwent primary transphenoidal pituitary surgery was analyzed. After excluding M.Cushing, patients undergoing additional radiation therapy and a secondary surgery as well as patients without sufficient follow-up data 101 patients were finally included in the study. Hydrocortisone dose amounted on the day of surgery to 150mg and was reduced daily up to 30mg on the 5th postoperative day (POD5). On POD6 the fasting cortisol level was measured and compared to the outpatient medical report concerning the termination date of hydrocortisone substitution and what preceding work-up the decision to terminate the substitution was based upon. Further characteristics of the patients, the operation, laboratory and follow-up data were collected and analyzed using the Pearson’s correlation coefficient to measure the linear correlation between two variables.

Results: Out of 101 patients 77 had a termination of hydrocortisone substitution within 0.5–25 months. The termination was based on mainly stimulation tests or clinical and laboratory features. The fasting cortisol levels (FCL) on POD6 of these patients were 1.6–196.2ng/ml (standard value 62–194mg/ml). The termination of HC intake had a positive correlation with the FCL (r=0.27) stating the higher the FCL level on POD6 was, the higher the probability for HC therapy termination. Taking the bottom standard value of FCL 62ng/ml as a cut-off parameter the specificity was 95%. Furthermore positive correlations were seen with complete tumor removal (r=0.29), hormone-active adenomas (r=0.23) and thyreotropic and gonadotropic sufficiency. Negative correlations were seen with preoperative HC substitution (r=-0.27), postoperative complications (r=-0.22) and tumor mass (r=-0.30).

Conclusion: The FCL examined on POD6 is a predictor for the recovery of the adrenocorticotropic axis after the performance of transsphenoidal pituitary surgery with a specificity rate of 95%. Preoperative HC intake and postoperative complications pointed to a persisting adrenocorticotropic failure.