Intraoperative blood pressure strategies and neurocognitive outcomes: A systematic review

Intraoperative blood pressure instability during anesthesia may compromise cerebral perfusion and has been associated with postoperative delirium and perioperative neurocognitive disorders. However, randomized evidence remains heterogeneous regarding whether targeted intraoperative blood pressure management strategies reduce postoperative neurocognitive complications compared with standard care.

We conducted a systematic review of randomized controlled trials evaluating intraoperative blood pressure, perfusion-related, ventilatory, or anesthetic strategies in adult surgical patients. The review was registered in PROSPERO and reported according to PRISMA 2020. Searches were performed in PubMed, EMBASE, and LILACS, with no language or publication-status restrictions. Study selection, data extraction, and risk-of-bias assessment were performed independently by two reviewers. Risk of bias was evaluated using the Cochrane Risk of Bias 2 tool. Because of clinical and methodological heterogeneity in interventions, populations, neurocognitive definitions, and follow-up timing, findings were synthesized narratively without meta-analysis.

Thirteen randomized controlled trials were included. Protocolized interventions, including prophylactic vasopressor infusion, individualized blood pressure targets, ventilatory adjustment, and regional or combined anesthetic techniques, were generally associated with improved hemodynamic stability and selected early perioperative benefits. Individualized blood pressure management reduced altered consciousness from 15.9% to 5.4% in one trial, while prophylactic norepinephrine reduced intraoperative hypotension from 74% to 15% in another. High normocapnia markedly reduced cerebral desaturation events from 55.6% to 8.8%. Trials evaluating sedative or anesthetic regimens, including esketamine, remimazolam, dexmedetomidine, desflurane, sevoflurane, and propofol-based strategies, suggested possible benefits on hemodynamic stability, analgesic requirements, and early recovery markers. However, evidence for sustained reduction in postoperative delirium or long-term perioperative neurocognitive disorders remained limited and inconsistent.

Protocolized intraoperative blood pressure and perfusion-related strategies may improve hemodynamic stability and reduce selected early perioperative complications. Nevertheless, current randomized evidence is insufficient to conclude that these strategies consistently prevent postoperative delirium or long-term perioperative neurocognitive disorders. Future trials should use standardized neurocognitive definitions, validated delirium instruments, longer follow-up, and complete reporting of absolute event rates and effect estimates.