Difference between arterial pressure in clino- and orthostatism. A method for evaluating preparation for pheochromocytoma intervention

Four patients with pheochromocytoma underwent pre-surgical treatment with phenoxybenzamine and volemic expansion. The postural hypotension was evaluated by daily monitoring of the arterial pressure and heart rate in clino orthostatism. The patients underwent surgery and hemodynamic monitoring by Swan-Ganz catheter when postural hypotension was at the lowest level. Hemodynamic data were: elevated cardiac output, normal systemic vascular resistance and filling pressure. These results confirm that the orthostatic hypotension reduction is a valid indication to evaluate the effectiveness of the treatment period with phenoxybenzamine and volemic expansion