Effect of Personalized Perioperative Blood Pressure Management on Postoperative Complications and Mortality in High-risk Patients Having Major Abdominal Surgery: a Multicenter Prospective Randomized Controlled Interventional Clinical Trial

Rates of major complications and mortality in the first weeks after surgery remain very high: postoperative mortality is still around 2% in central Europe and the United States. Postoperative deaths are a consequence of postoperative complications. Postoperative complications that are most strongly associated with postoperative death include acute kidney injury and acute myocardial injury. To avoid postoperative complications it is thus crucial to identify and address modifiable risk factors for complications. One of these modifiable risk factors may be intraoperative hypotension. Intraoperative hypotension is associated with major postoperative complications including acute kidney injury, acute myocardial injury, and death. It remains unknown which blood pressure value should be targeted in the individual patient during surgery to avoid physiologically important intraoperative hypotension. In current clinical practice, an absolute mean arterial pressure threshold of 65mmHg is used as a lower "one-size-fits-all" intervention threshold. This "population harm threshold" is based on the results of retrospective studies. However, using this population harm threshold for all patients ignores the obvious fact that blood pressure varies considerably among individuals. In contrast to current "one-size-fits-all" perioperative blood pressure management, the investigators propose the concept of personalized perioperative blood pressure management. Specifically, the investigators propose to test the hypothesis that personalized perioperative blood pressure management reduces the incidence of a composite outcome of acute kidney injury, acute myocardial injury, non-fatal cardiac arrest, and death within 7 days after surgery compared to routine blood pressure management in high-risk patients having major abdominal surgery. The investigators will perform preoperative automated blood pressure monitoring for one night to define individual intraoperative blood pressure targets. Automated blood pressure monitoring is the clinical reference method to assess blood pressure profiles. The mission of the trial is to reduce postoperative morbidity and mortality after major surgery. The vision is to achieve this improvement in patient outcome by using the innovative concept of personalized perioperative blood pressure management. This trial is expected to change and improve current clinical practice and will have a direct impact on perioperative blood pressure management guidelines.