Anesthetic management with propofol for pheochromocytoma resection under monitoring of bispectral index and blood volume]

In two patients, pheochromocytoma resection was performed under propofol/fentanyl anesthesia, while bispectral index (BIS) monitoring and blood volume measurement using pulse spectrophotometry were done. In one patient (Case 2), arterial blood concentrations of propofol were measured by high performance liquid chromatography (HPLC), and compared with those of the estimated blood concentrations. Continuous infusion of nitroprusside and bolus infusion of nicardipine and/or diltiazem were used when hypertension and tachycardia occurred. After resection of the tumor, propofol dosage was reduced keeping the BIS values around 60. In both patients, blood volume was maintained higher than normal value (Case 1: 79-101, and Case 2: 91-112 ml x kg(-1)) during operation. After tumor resection, the blood pressure was maintained well without rapid infusion of fluid or vasopressor. Arterial blood concentration of propofol was lower than the estimated blood concentration during operation in high blood volume case (Case 2). BIS monitoring and blood volume measurement are useful for adjustment of propofol dosage and for avoidance of hypotension after pheochromocytoma resection.