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 (IMPROVE-multi)

• Applicant: Professor Dr. Bernd Saugel
• Subject Area: Anaesthesiology
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 445158321

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 and deaths it is thus crucial to identify and address modifiable risk factors for complications. One of these modifiable risk factors may be intraoperative hypotension – i.e., low blood pressure during surgery. Intraoperative hypotension is associated with major postoperative complications including acute kidney injury, acute myocardial injury, and death. The medical problem is that it remains unknown which blood pressure value should be targeted in the individual patient during surgery with general anesthesia to avoid physiologically important intraoperative hypotension. In current clinical practice, an absolute mean arterial pressure threshold of 65 mmHg is used as a lower "one-size-fits-all" intervention threshold. This “population harm threshold” of 65 mmHg is based on the results of retrospective database 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, we propose the concept of personalized perioperative blood pressure management. Specifically, we 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. We 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 and an international consensus group recently defined it as "the optimal method to establish baseline values" before surgery. The mission of the trial is to markedly 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 guidelines of perioperative blood pressure management.

• DFG Programme: Clinical Trials
• Co-Investigator: Professor Dr. Frank M. Brunkhorst