Continuous intravenous infusions of phentolamine and esmolol for preoperative and intraoperative adrenergic blockade in patients with pheochromocytoma

Abstract

HE IMPORTANCE of preoperative adrenergic blockade in patients with pheochromocytoma is well recognized, with a-blockade being of primary importance. /3-adrenergic blockade has had a more limited role in these patients, and is usually reserved for the treatment of tachyarrhythmias.’ Long-lasting adrenergic antagonists have the potential disadvantage of persistent effects following tumor removal. Ideal agents for adrenergic antagonism in this condition would be rapidly acting, short-lasting (Y- and @blockers for precise control of blood pressure (BP) and heart rate (HR). Phentolamine (Regitine; Ciba-Geigy Ltd, Basel, Switzerland) is a useful drug for (Yblockade and BP control in patients with pheochromocytoma. It has the advantages of rapid onset and short duration and may be administered as a continuous infusion.’ Esmolol (Brevibloc; DuPont Critical Care, Waukegan, IL), a new intravenous (IV) &selective adrenergic antagonist, also possesses a rapid onset and short duration (T,,, is nine minutes),3 and has been used in the treatment of supraventricular tachycardias,4 attenuation of the stress response to intubation5 and prevention of myocardial ischemia during coronary artery surgery.6 Combined with a-blockade provided by phentolamine, esmolol should be an ideal agent for