Alpha and beta power increase may reflect sedative component of anesthesia. Simultaneous delta, alpha, and beta power increase may correlate with loss of consciousness. Theta and delta power increase may reflect surgical anesthesia. Opioid-induced gamma power decrease may reflect suppression of pain perception. Pentobarbital-, fentanyl-, and midazolam-induced immobility to noxious stimulation may be mediated supraspinally.

A 33-year-old woman weighing 108 kg with obesity and neurofibromatosis was presented with a 2-year history of poorly controlled hypertension, headaches, palpitations, and occasional chest pain. Her blood pressure was 170/100 mm Hg, and she was treated with daily oral dose of diltiazem (360 mg), hydrodiuril (12.5 mg), lisinopril (20 mg), and metoprolol XL (25 mg) tablets. Biochemical evaluation for pheochromocytoma showed elevated 24-hour urine metanephrine levels of 5496 mcg and normetanephrine level of 6415 mcg. A computed tomographic scan of the abdomen showed a 6 Â 6-cm right adrenal mass. The remainder of her preoperative tests was otherwise normal. Three weeks before surgery, the patient was started on phenoxybenzamine of 10 mg per day orally, which was gradually increased to 30 mg 3 times a day. The day before the planned surgery, the patient was admitted to surgical floor, her average blood pressure and heart rate were 134/76 mm Hg and 65 bpm, respectively. At midnight, she was given an extra dose of 40 mg of phenoxybenzamine and also received 1 L of 5% dextrose with 0.45% normal saline. The following morning patient was taken to the operating room, standard monitors were

No abstract