The Effect of Different Dexamethasone Doses Used for Prophylaxis Against Nausea-Vomiting on Serum Cortisol Level

Aim: Dexamethasone is used for prevention of postoperative nausea and vomiting (PONV). Most important side effect of steroid use is adrenal suppression. In this study we aimed to evaluate the effects of single dose of 2, 4, 8 mg dexamethasone on adrenal glands by measuring serum cortisol levels, and also in preventing postoperative nausea and vomiting. Material and Method: Forty patients scheduled for elective total nasal reconstruction under general anesthesia were included to the study. Patients were randomly divided into four groups. Immediately before the induction of anesthesia 2 ml intravenous serum physiologic to group S, 2 mg dexamethasone to group D2, 4 mg dexamethasone to group D4, 8 mg dexamethasone to group D8 were applied. Blood sampling was done from the patients at preoperative visit day (t0), preinduction and before dexamethasone injection (t1), after induction at 2. (t2), 6.(t3), 9. (t4),12. (t5),18.(t6), 24.(t7) and 72. (t8) hours for measurement of serum cortisol levels. Results: Demographic data, anesthetic and surgical times were similar in the groups. The 8 mg and 4 mg dexamethasone doses were found to be more effective than the control and D2 groups in prevention of PONV. In 4 and 8 mg groups no increase was observed in the cortisol levels. In 8 mg group there was significant suppression in cortisol levels between 9.and 24.hours of induction. Conclusion: Both 4 and 8 mg dexamethasone doses are effective for prevention of PONV. Because 8 mg dexamethasone causes suppression of serum cortisol levels, we think that the application of 4 mg dexamethasone is safer than 8 mg.