A comparison of the activity of the sympathoadrenal and adrenocortical system under inhalation anesthesia techniques.

Epinephrine, norepinephrine, ACTH and cortisol plasma levels as well as heart rate and blood pressure were studied in 32 patients undergoing ophthalmic surgery. Epinephrine levels rose significantly during nitrous oxide anesthesia and also during enflurane-nitrous oxide anesthesia, whereas they fell slightly during halothane-nitrous oxide anesthesia. Norepinephrine levels remained unchanged. ACTH and cortisol levels increased during all three types of anesthesia. During nitrous oxide and enflurane-nitrous oxide anesthesia, heart rate and blood pressure were elevated, halothane nitrous oxide anesthesia was associated with an increased heart rate but not with increased blood pressure.