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

Abstract

The preparation for phaeochromocytoma surgery is a matter of debate. Pre-operative blockade of a-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 a-1 receptors. Our findings indicate the value of aggressive blockade of a-1 receptors in preparation for surgery of phaeochromocytoma.

Point of controversy: perioperative care of patients undergoing pheochromocytoma removal–time for a reappraisal?

“…This improved prognosis is currently attributed to the widespread preoperative administration of vasodilating drugs and large fluid volumes, even in patients with normal or borderline elevation of catecholamine levels (5,(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). Nevertheless, none of these practices are evidence based, and to our opinion, a critical review of the available literature does not support this dogma.…”

“…Mortality has no longer been reported in most recent studies of patients undergoing pheochromocytoma removal (11,12,18,22,31). This improved prognosis is currently attributed to the widespread preoperative administration of vasodilating drugs and large fluid volumes, even in patients with normal or borderline elevation of catecholamine levels (5,(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30).…”

“…Epidural and spinal anesthesias have been used alone or as a complement to general anesthesia for pheochromocytoma removal with satisfactory results (15,22,29). However, they do not provide the best comfort when carrying out an adrenalectomy (10-12), and sympathetic blockade associated with spinal anesthesia does not protect against the hemodynamic effects of catecholamine release during tumor manipulation (13,16,29,35).…”

“…nicardipine infusion or bolus is currently used in patients undergoing pheochromocytoma removal (18, 50). -Urapidil is an a-blocking agent that was judged useful in managing hypertension following the induction of anesthesia and during tumor dissection in patients undergoing pheochromocytoma removal (22). Heart rate did not change significantly (22).…”

“…The subsequent sudden intraoperative withdrawal of vasopressors following pheochromocytoma resection was believed to cause abrupt relaxation of the vascular bed, in turn resulting in hypotension and shock unless the reduced blood volume was restored (13)(14)(15). This led to the assumption that optimal preoperative care had to include preoperative vasodilation of the previously constricted vascular compartment by a vasodilating drug along with restoring blood volume by major fluid infusion (5,(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30).…”