Cerebral Autoregulation and Delirium Study

Reducing Delirium After Cardiac Surgery: Personalized Targeted Blood Pressure Management Strategy Using Cerebral Autoregulation Monitoring: A Pilot Study

Approximately one in four elderly patients develops postoperative delirium (POD) after cardiac surgery. POD is associated with prolonged hospitalization, increased mortality, and higher health care costs. While patient-related risk factors are often difficult to modify, surgery- and anesthesia-related factors may be optimized to reduce the incidence of POD. One potentially modifiable factor is intraoperative blood pressure management. Current practice commonly relies on standardized blood pressure targets during cardiac surgery; however, this "one-size-fits-all" approach may not account for individual variability in cerebral perfusion requirements. This study proposes a personalized blood pressure management strategy based on real-time monitoring of cerebral autoregulation, with the goal of maintaining optimal cerebral perfusion and protecting the brain from both hypo- and hyper-perfusion

The primary aim of this pilot study is to evaluate the feasibility of conducting a subsequent definitive trial by assessing recruitment rates, protocol adherence, and the completeness and quality of short-term outcome data collection. The pilot study will also provide an opportunity to identify potential challenges and optimize the design of the larger trial, if necessary.

If the study hypothesis is confirmed and subsequently reproduced in larger, rigorous clinical trials, the findings could have important implications for intraoperative blood pressure management in elderly patients undergoing cardiac surgery. Specifically, this research may support a transition from the current "one-size-fits-all" blood pressure management strategy toward an individualized, real-time approach guided by cerebral autoregulation monitoring. Such a personalized strategy could potentially reduce the incidence of postoperative delirium (POD) in this high-risk population.

Conversely, premature implementation of personalized blood pressure management based solely on the currently available preliminary evidence may lead to unintended adverse consequences. Therefore, the proposed pilot study is essential to provide critical feasibility and safety data before proceeding to a larger definitive trial.

This study will be conducted as a prospective, single-centre, randomized controlled clinical trial comparing a real-time cerebral autoregulation monitoring-based blood pressure management strategy with standard care. Participants will be randomized into two groups:

Intervention Group: Blood pressure management guided by real-time cerebral autoregulation monitoring.

Control Group: Standard intraoperative blood pressure management according to current institutional practice.

Inclusion Criteria:

• Consenting patients aged ≥ 60 years undergoing elective complex cardiac surgery (coronary artery bypass grafting plus valve surgery, double-valve surgery, triple-valve surgery, redo operations, or aortic arch surgery), or patients aged ≥ 70 years undergoing isolated coronary artery bypass grafting or single-valve repair/replacement surgery.

Exclusion Criteria:

• Patients with symptomatic cerebrovascular disease.
• History of delirium.
• Major neurocognitive impairment (e.g., dementia or Mini-Mental State Examination score < 10).
• Schizophrenia.