Morning Serum Cortisol Level After Transsphenoidal Surgery for Pituitary Adenoma Predicts Hypothalamic-Pituitary-Adrenal Function Despite Intraoperative Dexamethasone Use

Abstract

Perioperative glucocorticoid (GC) is rarely needed in patients undergoing transsphenoidal surgery (TSS). We instituted a steroid-sparing protocol in the settings of intraoperative dexamethasone use. We evaluated the safety of using a cut off cortisol level of 14 μg/dL on postoperative day (POD)-1 and -6 after dexamethasone use during the surgery. We also analyzed the efficacy of serial morning cortisol levels for weaning GC replacement. The charts of 48 adult patients who received dexamethasone 4 mg intraoperatively were reviewed. Morning cortisol levels were measured on POD-1. Patients with cortisol ≥14 μg/dL were discharged without CG replacement. Morning cortisol level was checked routinely on POD-6, and GC replacement was initiated when the level was <14 μg/dL. Serial cortisol levels were measured in patients requiring GC after the first postoperative week. Overall, 67% patients had POD-1 cortisol ≥14 μg/dL and did not require GC on discharge. After POD-6, 83% of patients were not on GC replacement. A cosyntropin stimulation testing (CST) was only performed in 3 patients. There were no hospital admissions for adrenal crisis during the postoperative period. A steroid-sparing protocol with POD-1 and -6 morning cortisol levels can be safely and effectively used in the settings of intraoperative dexamethasone administration. It leads to avoidance of GC in more than two-thirds of patients on discharge and more than 80% of patients after the first postoperative week. We found that dynamic adrenal testing could be omitted in the majority of patients by using serial morning cortisol levels to assess the hypothalamic-pituitary-adrenal (HPA) axis.