[Strategies for perioperative pain management and the prevention and management of postoperative delirium in frail older patients].

Postoperative pain and postoperative delirium (POD) may share some pathophysiological mechanisms in frail older patients. Persistent nociceptive input, accumulation of analgesic drugs, hemodynamic fluctuations, and respiratory depression may increase the risk of acute brain dysfunction. Potential mechanisms include blood-brain barrier disruption and neuroinflammation, disturbances in cerebral perfusion and oxygen metabolism, and disruption of sleep and arousal networks. A systematic review suggests a dose-response relationship between postoperative pain intensity and POD, although the certainty of the evidence is low and causality remains unproven. This article proposes a "dual-exposure, three-pathway, closed-loop management" framework for perioperative analgesia and the prevention and management of postoperative delirium in frail older patients. Preoperative assessment should include frailty, cognitive status, and pain-related risk. Intraoperatively, precision multimodal analgesia should be tailored to incisional, visceral, and inflammatory pain, with the regimen adjusted using data from nociception, electroencephalographic, cerebral oxygenation, and hemodynamic monitoring. Postoperatively, pain should be assessed repeatedly over time, together with concurrent screening for POD and identification of reversible precipitating factors. The goal of analgesia in frail older patients should not be defined simply as "zero pain" or complete avoidance of opioids. Instead, adequate analgesia should be provided while minimizing treatment-related adverse effects that may impair brain function.