PERIOPERATIVE BRAIN PROTECTION IN MODERN ANESTHESIA: NEUROINFLAMMATION, CEREBRAL AUTOREGULATION, AND STRATEGIES TO PREVENT POSTOPERATIVE NEUROCOGNITIVE DISORDERS

Abstract

Perioperative neurocognitive disorders threaten functional recovery after surgery, particularly in older adults with cognitive impairment, frailty, or cerebrovascular disease. Their prevention requires a framework that connects surgical inflammation with cerebral perfusion, anesthetic exposure, and the conditions of postoperative recovery. This narrative review examines the biological basis and clinical evidence for perioperative brain protection, with particular attention to neuroinflammation, cerebral autoregulation, and interventions intended to prevent postoperative delirium and subsequent cognitive decline. Experimental studies implicate damage associated molecular signals, cytokine-mediated blood–brain barrier dysfunction, recruitment of peripheral immune cells, and altered microglial activity in postoperative memory impairment. Human biomarker studies support inflammatory and neuronal-injury associations but have not established a clinically actionable molecular phenotype. Cerebral autoregulation offers a rationale for individualized perfusion management; however, promising cardiac surgical studies have not established a universal blood pressure target or a consistent reduction in longer-term neurocognitive disorders. Trials of electroencephalography-guided anesthesia have produced conflicting results, and major hip-fracture trials have not demonstrated that regional anesthesia alone prevents delirium. Dexmedetomidine has the strongest current pharmacological evidence for reducing postoperative delirium in selected settings, although heterogeneous regimens and cardiovascular adverse effects require careful interpretation. Evidence for preventing persistent postoperative neurocognitive disorder remains substantially less secure. Multicomponent care that identifies baseline vulnerability, supports physiological stability, provides effective analgesia, preserves sleep and mobility, and detects delirium systematically remains central to practice. Future studies should combine mechanistic phenotyping with standardized cognitive outcomes, rigorous follow-up, and implementation assessment. Contemporary perioperative brain protection is best understood as individualized, coordinated care across the surgical pathway, with interventions judged by patient-centered recovery rather than physiological or biomarker changes alone.