Endocrine Abstracts

Introduction: Resecting a pheochromocytoma is a high-risk surgical procedure, life threatening complications may occur. In this presentation, we reported a case of resistance hypotension after pheochromocytoma resection.

Case: A 70-year-old male with a history of prostate adenocarcinoma admitted to urology policlinic for cancer screening. Abdominal ultrasound revealed 6.5×5.5 cm mass in left adrenal gland and patient referred to endocrinology policlinic. He had history of diabetes for 10 years and hypertension. In physical examination blood pressure and pulse were 120/80 mmHg and 75 beats/ min respectively. In laboratory investigations fasting blood glucose was 121 mg/dl, A1C was 9.7%. Plasma renin activity, plasma aldosterone concentration and aldosterone to renin ratio were all normal. 24 h urine metanephrine and normatenephrine were 7053 μg/day (52–341) and 5533 μg/day (88–444) respectively. Surrenal MR detected 6.9×5.2×5.5 cm adenom in right adrenal that enhanced after gadolinium and hyperintens on T2 weighted images. Pheochromocytoma was diagnosed and right surrenalectomy was planned. For premedication patient was hospitalized 10 days before operation. First doxazosin and then metoprolol started. 3 day before operation patients was hydrated with i.v. saline. Preoperative blood pressure and pulse were 120/80 mmHg, 72 beats/min respectively. Intraoperatively short time sodium nitroprusside was used due to hypertensive spell. After removing the mass severe hypotension occurred (60/40 mmHg). Even though administration of i.v. saline, 20 μg/kg per min adrenaline, 15 μ/kg per min noradrenaline, 20 μ/kg per min dopamine and 40 mg prednol, blood pressure did not increase. After 1 h postoperatively blood pressure was 80/40 mmHg. Patient screened in intensive care unit and adrenaline infusion continued for 12 h then blood pressure increased gradually and adrenaline infusion ceased.

Discussion: First line treatment in pheochromocytoma is surgery. Premedication is important to prevent preoperative and postoperative complications. Inadequate premedication may cause hypertensive crisis before resection and severe hypotension after resection. There are many cause for postoperative severe hypotension include residual a-blockade, residual action of vasodilators, inadequate volume replacement and adrenoceptor down-regulation. As a consequence even though adequate premedication severe hypotension may be seen and it should be resistance to catecholamines, in this situation high dose catecholamines or alternative approaches (such as vasopressine infusion) should be used.