Unexpected pheochromocytoma--a case report of anesthesia in a uremic patient.

Pheochromocytoma is an uncommon neoplasm causing blood pressure changes. It may go undiagnosed in uremic patients in whom hypertension is common. The preferential diagnostic work-up, including urine and serum catecholamine measurements, is unsuitable for uremic patients due to anuria and inherent increases in serum catecholamine levels. Here, we present a case of uremia, scheduled for right adrenalectomy and simple nephrectomy, who had been sustaining hypertension. Malignant hypertension was only discovered during surgical manipulation of the adrenal tumor. Pheochromocytoma was highly suspected. The patient was treated with nitroglycerin, fentanyl, and increased concentration of isoflurane to deepen the anesthesia. However, the results were only fair and after ligation of the tumor veins, hypotension ensued. Pathological examination verified the diagnosis of pheochromocytoma. In reviewal of the whole course of treatment, it was considered that the placement of a pulmonary artery catheter to detect volume shifts and changes in hemodynamic status was indicated. Related papers were reviewed and application of diagnostic tools and their limitations, safety and efficacy of anesthetics and vasodilators, and possible complications relevant to management of pheochromocytoma were also discussed. In conclusion, it is important to remain alert, administer agents cautiously, and set up complete monitoring if needed, and carry out postoperative intensive care to lessen complications in the anesthetic management of this rare and dangerous incidentaloma encountered during anesthesia.