gms | German Medical Science

Objective: Postoperative nausea and vomiting is common after general anaesthesia and is reported by approximately 20–25% of patients. The standard prophylaxis at the authors department is a single treatment of 4mg of dexamethasone before initiating anaesthesia. Dexamethasone is known to suppress adrenocorticotrophic hormone (ACTH) and cortisol levels. The objective was to find out whether this prophylaxis has an effect on postoperative levels of cortisol in patients undergoing transsphenoidal pituitary surgery and therefore simulates pituitary deficiency.

Method: 36 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 and were compared to blood tests of patients who had no history of PONV and therefore received no prophylaxis. Patients with Cushing's disease were excluded.

Results: Patients who were treated with a dexamethasone PONV-prophylaxis showed no significant changes of cortisol levels; preoperative median of 93 ug/l (range 39-427) and a postoperative median of 87 ug/l (range 10–733) (p=0.798) opposed to patients who did not receive such treatment; preoperative cortisol 114 ug/l (range 10–387) and postoperative levels of 273 ug/l (range 10–1,352) (p<0.001)

Conclusions: Cortisol levels after pituitary surgery usually rise due to the stress reaction and therefore are a good indicator for sustained pituitary function. As early postoperative blood checks of cortisol levels yield important information about potential pituitary sufficiency after transsphenoidal surgery, the probability that dexamethasone PONV prophylaxis suppresses postoperative cortisol levels must be considered.