Hypertensive responses during operation for phaeochromocytoma: a study of plasma catecholamine and haemodynamic changes.

Virtually all patients undergoing resection of a phaeochromocytoma exhibit hypertensive crises at some period perioperatively. In order to study the events associated with hypertensive responses, cardiovascular variables were measured with a Swan-Ganz pulmonary artery catheter and plasma catecholamine levels were determined simultaneously in eight patients during surgery for phaeochromocytoma. Hypertensive responses requiring vasodilator treatment occurred in five patients, i.e. systolic blood pressure (BP) greater than 200 mmHg for more than 1 min. Transient elevation, at least in systolic BP, to greater than 200 mmHg occurred in all patients. Hypertensive responses were identified associated with two circumstances: the first in association with noxious stimuli, i.e. intubation, skin incision, etc., but were not generally accompanied by an elevation in plasma noradrenaline and adrenaline levels; the second occurring during tumour manipulation were more severe and were always accompanied by elevated plasma noradrenaline and adrenaline levels. Transient left ventricular dysfunction, defined by increased pulmonary capillary wedge pressure (PCWP) and decreased cardiac index (CI) secondary to a marked increase in systemic vascular resistance (SVR), was observed in four patients during palpation of the tumour, while one patient exhibited more marked and prolonged ventricular dysfunction. It is concluded that hypertensive responses associated with noxious stimuli may be controlled with deep anaesthesia while those due to tumour manipulation cannot be prevented and are best treated with vasodilators.