Inadvertent diagnosis of pheochromocytoma after endoscopic premedication.

Hypertensive crisis in a patient with pheochromocytoma can be induced by endoscopy premedication. Opiates, glucagon, and metoclopramide are commonly used in the gastrointestinal laboratory and capable of releasing catecholamines from a pheochromocytoma. Patients who have just had endoscopy can display untoward effects such as nausea, weakness, and diaphoresis. Such patients should probably have their blood pressure carefully recorded. Although hypotension is expected, endoscopists should be alert to the finding of severe hypertension and consider pheochromocytoma. The need for this becomes even greater considering that primary gastrointestinal endoscopy is often being done in doctor's offices away from hospitals and more acute resuscitative resources. In the case reported, a life-threatening hypertensive crisis was induced by fentanyl. The hypertensive crisis was correctly ascribed to pheochromocytoma, enabling institution of lifesaving treatment.