Unexpected pheochromocytoma leading to cardiac arrest during the perioperative period: a case report and literature review.

Background: Pheochromocytomas (PCCs) are rare neuroendocrine catecholamine (CA)-secreting tumours that originate from chromaffin tissue and can produce and store CAs. Unexpected PCCs pose a serious threat to the perioperative safety of patients and a considerable challenge to anaesthesiologists because of the risks of fatal hypertensive crises and other stresses.

Case presentation: A 37-year-old woman who was scheduled for tonsillectomy and palatopharyngoplasty under general anaesthesia experienced a malignant cardiovascular event after induction, which was characterized mainly by a sharp increase in heart rate and blood pressure, ultimately leading to cardiac arrest and the occurrence of secondary long QT syndrome. Based on the perioperative clinical manifestations, measurements of plasma and urinary CAs, postoperative bilateral adrenal computed tomography results and surgical pathological results, the patient was diagnosed with an undiagnosed PCC.

Conclusions: Anaesthesiologists should pay attention to patients with recurrent chest tightness, as these patients may have an undiagnosed PCC. Extreme hypertension and tachycardia during the perioperative period may indicate a PCC. We should not automatically use beta-adrenergic receptor blockade while overlooking the importance of alpha-adrenergic receptor blockade. If a serious malignant cardiovascular event occurs in patients with an undiagnosed PCC during the perioperative period, multidisciplinary comprehensive treatment is crucial.