[Use of urapidil during surgery for pheochromocytoma].

OBJECTIVE

To investigate the efficacy of urapidil, administered either by boluses or a continuous infusion, to control hypertension during resection of phaeochromocytoma.

STUDY DESIGN

Prospective open study.

PATIENTS

Seven consecutive patients aged between 23 and 60 years, with a hypersecretant phaeochromocytoma.

METHODS

Standard anaesthetic technique including thiopentone, opioid, muscle relaxant, nitrous oxide and isoflurane. Invasive haemodynamic monitoring with a Swan-Ganz catheter and radial arterial catheterization. Infusion of cristalloids and colloids (20 mL.kg-1.h-1). Evaluation of two regimens of urapidil administration following the initial injection of a bolus of 25 mg in case of severe hypertension i.e. SAP > 180 mmHg > 1 min: a) boluses of 25 or 50 mg of urapidil injected according to the response obtained after the first bolus or in case of resurgence of a new hypertensive event; b) continuous infusion of 150-200 mg.h-1.

RESULTS

Three patients developed hypertension between the induction of anaesthesia and the beginning of the tumor dissection. One bolus of 25 or 50 mg of urapidil was efficient to control this event. During the dissection of the phaechromocytoma, higher doses (75-100 mg) were required to significantly decrease SAP and DAP values (P < 0.001). Heart rate did not change significantly in patients not receiving esmolol. A continuous infusion, used in three patients, did not prevent the occurrence of peaks in two patients, requiring additional doses. After the removal of the tumor, three patients experienced severe hypotension with decreased systemic vascular resistances and high cardiac output. Vasoactive drugs were injected to restore better haemodynamic conditions.

CONCLUSION

Urapidil is useful for the management of hypertension during the resection of phaechromocytoma. However further investigations are needed to determine its role in the occurrence of prolonged collapse after the tumor removal.