Background: Adrenal insufficiency is a feared complication in patients undergoing transphenoidal surgery (TSS). Using the insulin tolerance test (ITT) for the preoperative assessment of hypothalamic-pituitary-adrenal (HPA) status is less than ideal, and the morning serum cortisol (MSC) is often used as a proxy for ITT. However, neither the ITT nor the MSC level has been validated to indicate HPA sufficiency compared to a physiological gold standard such as patients' ability to withstand transphenoidal surgery.
Objective: To evaluate the intraoperative and postoperative course of nine patients with non-ACTH-secreting pituitary adenomas who did not receive intraoperative cortisol replacement despite having a preoperative MSC below 9 μg/dl (250 nmol/l) and to compare this with a set of patients with a preoperative MSC greater than 14.5 μg/dl (400 nmol/l) and another set of patients with MSC below 9 μg/dl (250 nmol/l) who received intraoperative cortisol administration.
Methods: Preoperative and day 1 and day 2 postoperative MSC, intraoperative anesthetic record, vital signs, fluid balance, medications, and complications were recorded.
Results: None of the patients experienced the full syndrome of adrenal insufficiency. One patient with a preoperative MSC <9 μg/dl (250 mol/l) had isolated postoperative fatigue and required cortisol replacement. No patient suffered any life-threatening complications. There were no differences among the three groups in their intraoperative or postoperative courses when compared for intraoperative hypotension, acute blood pressure drop, and administration of vasopressors.
Conclusion: This study suggests that TSS can be performed safely in patients with preoperative MSC less than 9 μg/dl (250 nmol/l) in closely monitored settings without intraoperative cortisol administration. Further studies are warranted.