Postoperative delirium: from bundles to precision prevention.

Perioperative brain health, encompassing postoperative delirium (POD) and longer-lasting cognitive decline, has become a major priority for patient safety and quality of recovery in older surgical patients. The 2018 unified nomenclature introduced perioperative neurocognitive disorders as an umbrella term spanning pre-existing neurocognitive disorder, POD, delayed neurocognitive recovery, and postoperative neurocognitive disorder. The incidence of POD varies widely, reflecting differences in age, baseline cognition, surgical type, and ascertainment; however, its clinical footprint is consistently substantial, with increased mortality, longer hospitalization, and downstream cognitive deterioration. Electroencephalography (EEG)-guided anesthesia trials have yielded mixed results, favoring its integration with hemodynamic optimization and medication stewardship. Screening uptake remains < 10% in many settings, limiting the ability to provide scalable and equitable brain care. Current prevention standards prioritize multicomponent, non-pharmacological bundles such as mobilization, reorientation/cognitive stimulation, sleep promotion, sensory optimization, hydration, nutrition, oxygen delivery, and prompt management of precipitating factors. Nonetheless, translation to "precision prevention" is constrained by three gaps: low implementation of recommended screening pathways, heterogeneity and limited transportability of prognostic models, and an under-operationalized vulnerability domain in which frailty and malnutrition lack standardized tools, cut-offs, and linked interventions. Biomarkers and perioperative physiology including EEG suppression patterns and individualized perfusion targets are biologically coherent adjuncts for risk refinement; however, current evidence supports their use as additive stratifiers within bundles rather than stand-alone gatekeepers. Next-generation perioperative brain health studies should standardize vulnerability phenotyping, integrate evidence-based selective monitoring and biomarker-informed refinement, and embed these elements into scalable workflows that convert guidelines into practical bedside actions.