Postoperative management of patients with pheochromocytoma.

The optimal preoperative and postoperative management of patients with pheochromocytoma demands a multidisciplinary approach. We report on 5 recent patients to illustrate the large volumes of fluid needed in the early postoperative period. This large fluid requirement is owing to a combination of a change in vascular compliance after excision of a pheochromocytoma, the residual effects of specific preoperative medications (phenoxybenzamine and alpha-methyl-p-tyrosine) and the loss of fluid into the retroperitoneal compartment (third space) produced by extensive dissection. It takes 3 half-lives (36 hours) to dissipate the effects of phenoxybenzamine and alpha-methyl-p-tyrosine, which corresponds to the time in which these patients require large volumes of intravenous fluids.