Preparation for surgery of phaeochromocytoma by blockade of alpha-adrenergic receptors with urapidil: what dose?

The preparation for phaeochromocytoma surgery is a matter of debate. Pre-operative blockade of alpha-1 receptors is increasingly employed in an attempt to reduce the risk of hypertensive episodes, especially during manipulation of the tumour. In this study, we compared the interest of an almost complete blockade of these receptors by high doses of urapidil in comparison with that of moderate doses of this drug. The study was conducted in two consecutive series of 18 patients, the first treated by a moderate dose, and the second by the highest dose tolerated by the patient. The two groups were comparable in other respects. All patients were operated under laparoscopy by the same surgeon and managed by the same anaesthetist using the same protocol. The number of hypertensive peaks was significantly reduced using the high dose of urapidil, with no more hypotensive episodes after tumour removal in this group. The area under the curve of norepinephrine levels as a function of time was significantly larger with the high doses of urapidil, arguing in favour of a more complete blockade of alpha-1 receptors. Our findings indicate the value of aggressive blockade of alpha-1 receptors in preparation for surgery of phaeochromocytoma.