Endocrine Abstracts

Objective: Postoperative nausea and vomiting is common after general anaesthesia and is reported by ~20–25% of all patients. The standard prophylaxis at the authors department is a single treatment of 4 mg of dexamethasone before initiating anesthesia. Dexamethasone is known to suppress ACTH and cortisol levels. The objective was to find out whether the standard PONV-prophylaxis of 4 mg of dexamethasone has an effect on postoperative levels of cortisol in patients undergoing transsphenoidal pituitary surgery and therefore simulates pituitary defency or in cases of cushings masks persistent disease.

Methods: consecutive patients who were operated during a course of 6 months were included. 19 patients with a known history of PONV received a standard dose of 4 mg of dexamethasone perioperatively. Blood tests were drawn at the first postoperative day in the usual manner and were compared to blood tests of patients who had no history of PONV and therefore received no prophylaxis.

Results: Patients who were treated with a dexamethasone PONV-prophylaxis showed no significant changes of cortisol levels; preoperative median of 93 ng/ml, range 39–265 ng/ml postoperative 92 ng/ml, range 10–733 ng/ml (P=0.353) opposed to patients who did not receive such treatment; preoperative 127.5 ng/ml, range 10–387 ng/ml vs postoperative 263 ng/ml, range 10–1016 ng/ml (P<0.001). Paired t-test was used to determine significance.

Conclusions: As the early postoperative blood checks of cortisol levels yields very important information about potential pituitary insufficiency after transsphenoidal surgery, it is of crucial information that dexamethasone PONV prophylaxis suppresses (in analogy to a dexamethasone suppression test) postoperative cortisol levels in such a significant manner.