Use of magnesium sulphate in the anaesthetic management of phaeochromocytoma: a review of 17 anaesthetics.

Seventeen anaesthetics are described in 16 patients with phaeochromocytoma in whom magnesium sulphate (MgSO4) was the principal anti-adrenergic agent used. In 15 of the 17 anaesthetics, MgSO4 produced satisfactory control of cardiovascular changes at induction and tracheal intubation, but in four of these additional sodium nitroprusside was required to control the arterial pressure during handling of the tumour. In one pregnant patient undergoing Caesarean section, MgSO4 was ineffective in controlling cardiovascular disturbances because of inadequate serum magnesium concentrations. This patient had a magnesium deficit before operation. In another patient, diagnosis was made during operation and MgSO4 provided satisfactory control of the crisis. Catecholamine release was studied in five patients and MgSO4 was found to reduce catecholamine concentrations from the time of induction until tumour handling.