Hypothalamic-Pituitary-Adrenal (HPA) axis in the Postoperative Period: Poor Dexamethasone Suppressibility in Subjects with Normal HPA function

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 50-71-HPA Axis
Clinical
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-58
Katia El Sibai*1, Heitham Ajlouni2, Warren Selman2 and Baha M Arafah3
1University Hospitals Case Medical Center, Cleveland, OH, 2University Hospitals, Case Medical Center, Cleveland, OH, 3Case Western Reserve Univ, Cleveland, OH
Background: HPA function is highly activated during the peri- and postoperative period as evident by elevated cortisol and ACTH levels. Similar features are reported during major stresses and critical illnesses. The dynamics of HPA function in the peri-operative period have not been well studied. The goal of this investigation was to examine whether HPA function can be suppressed with DEX during the peri-operative period.

Methods: Generally, patients with pituitary adenomas are not treated with glucocorticoids during/after transsphenoidal surgery unless they have deficiency. At times, single or multiple doses of DEX are administered to some patients peri-operatively. The current study included 9 patients who had normal HPA function preoperatively and who inadvertently received DEX peri-operatively. They were treated with a single (4-20 mg, mean 9.2; n=5) or multiple doses (8-40mg, mean 26mg/day; n=4) of DEX during the first 24 postoperative hours. While receiving DEX, HPA function was assessed by repeated measurements of ACTH and Cortisol levels. Their data were compared to other patients (controls) who had the same surgical procedure, had normal preoperative HPA function, had similar ages and gender distribution, but received no glucocorticoids peri-operatively. Plasma ACTH and cortisol levels were measured repeatedly during the first 24 hours after surgery in all patients.

Results: At all time intervals, the data of patients who had one dose of DEX and that of patients who took multiple doses were similar and were combined to represent DEX-treated subjects. Serum cortisol and plasma ACTH levels preoperatively in DEX-treated subjects (13.9±10.8 ug/dL; 42.6±10.7 ng/L respectively) were similar to those observed in subjects who were not given DEX (11.3±8.4 ug/dL;16.3±11.6 ng/L respectively). Eight hours after surgery, cortisol and ACTH levels in the DEX-treated subjects (25.7±12.9 ug/dL; 124.4±186 ng/L respectively) were similar to those of controls (34.4±12 ug/dL;123±99 ng/L respectively). Cortisol and ACTH levels drawn at 12, 18 and 24 hours after surgery in the DEX treated patients were similar to those of controls.

Summary and Conclusions: HPA function is highly activated in the peri-operative period, a feature similar to that observed in the critically ill. The stimuli for this activation are powerful enough that they can’t be suppressed with large doses of DEX. Caution is warranted in evaluating hypercortisolism in the peri-operative period.

Nothing to Disclose: KE, HA, WS, BMA

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm