Abstract: Pheochromocytoma and paraganglioma (PPGL) are rare neuroendocrine tumors, and intraoperative hemodynamic instability (IHI) represents a major challenge in their perioperative management. This article systematically reviews three routinely used parameters for evaluating preoperative preparation: preoperative blood pressure, duration of α-adrenergic blockade, and clinical symptoms. These parameters primarily reflect static hemodynamic status or indirect pharmacological effects and therefore may not comprehensively characterize vascular reactivity and peripheral perfusion. Moreover, their predictive value for IHI remains limited. As a noninvasive and continuous measure of dynamic perfusion, the peripheral perfusion index (PPI) reflects changes in peripheral vascular tone and tissue perfusion and may provide complementary information for assessing the adequacy of preoperative preparation in patients with PPGL.

Key words: pheochromocytoma, paraganglioma, hemodynamics, α-adrenergic receptor blocker, peripheral perfusion index