Dexamethasone PONV Prophylaxis Alters the Hypothalamic-Pituitary-Adrenal Axis After Transsphenoidal Pituitary Surgery

BACKGROUND: Postoperative nausea and vomiting (PONV) is common after general anesthesia and are reported by approximately 20% to 25% of all patients and up to 39% of patients undergoing neurosurgical procedures. The most common standard prophylaxis is a single application of 4 mg of dexamethasone before initiating anesthesia. Dexamethasone is known to suppress adreno-corticotroph hormone and cortisol levels. The objective was to find out whether this prophylaxis has an effect on the postoperative levels of cortisol in patients undergoing transsphenoidal pituitary surgery, and therefore simulates pituitary deficiency.

PATIENTS AND METHODS: A retrospective analysis of the files of 136 consecutive patients who were operated during a course of 6 months were included. Nineteen 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 and were compared with 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 in cortisol levels; preoperative median of 93 μg/L (range, 39 to 427) and a postoperative median of 87 μg/L (range, 10 to 733; P=0.798) opposed to patients who did not receive such treatment; preoperative cortisol 114 μg/L (range, 10 to 387) and postoperative levels of 273 μg/L (range, 10 to 1352; P<0.001).

CONCLUSIONS: As early postoperative blood checks of the cortisol levels yield important information about potential pituitary sufficiency after transsphenoidal surgery, the probability that dexamethasone PONV prophylaxis suppresses postoperative cortisol levels should be considered.