Postoperative mortality within 30 days after surgery is around 2% in patients having major noncardiac surgery in Europe and the USA. In fact, if the first 30 days after surgery were considered a disease, it would be the third leading cause of death globally. Postoperative deaths are a consequence of postoperative organ injury and complications - including acute myocardial injury, acute kidney injury, and severe infectious complications. To avoid postoperative deaths, it is thus crucial to reduce postoperative organ injury and complications. To reduce postoperative organ injury and complications, modifiable risk factors need to be addressed. These modifiable risk factors for postoperative organ injury include low blood flow states and intraoperative hypotension. Optimizing blood flow (i.e., cardiac index) during surgery may thus be effective in reducing postoperative organ injury and complications. However, the optimal hemodynamic treatment strategy for high-risk surgical patients remains unclear. Cardiac index varies substantially between individuals. However, current intraoperative hemodynamic treatment strategies mainly aim to maximize cardiac index instead of using personalized cardiac index targets for each individual patient. A single-center pilot trial suggests that using individualized cardiac index targets during surgery may reduce postoperative organ injury and complications compared to routine hemodynamic management. However, large robust trials investigating the effect of personalized hemodynamic management targeting preoperative baseline cardiac index on postoperative complications are missing.

The investigators, therefore, propose a multicenter randomized trial to test the hypothesis that personalized intraoperative hemodynamic management targeting preoperative baseline cardiac index reduces the incidence of a composite outcome of acute kidney injury, acute myocardial injury, non-fatal cardiac arrest, severe infectious complications, and death within 7 days after surgery compared to routine hemodynamic management in high-risk patients having elective major abdominal surgery.

not provided

Inclusion Criteria:

Consenting patients ≥45 years scheduled for elective major abdominal surgery (involving visceral organs) under general anesthesia that is expected to last ≥90 minutes AND presence of ≥1 of the following high-risk criteria:

• exercise tolerance <4 metabolic equivalents as defined by the guidelines of the American College of Cardiology/American Heart Association
• renal impairment (serum creatinine ≥1.3 mg dL-1 or estimated glomerular filtration rate <90 mL min-1 (1.73 m2)-1 within the last 6 months
• coronary artery disease
• chronic heart failure (New York Heart Association Functional Classification ≥II)
• valvular heart disease (moderate or severe)
• history of stroke
• peripheral arterial occlusive disease (any stage)
• chronic obstructive pulmonary disease (any stage) or pulmonary fibrosis (any stage)
• diabetes mellitus requiring oral hypoglycemic agent or insulin
• immunodeficiency due to a disease (e.g., HIV, leukemia, multiple myeloma) or therapy (e.g., immunosuppressants, chemotherapy, radiation, steroids [above Cushing threshold])
• liver cirrhosis (any Child-Pugh class)
• body mass index ≥30 kg m-2
• history of smoking within two years of surgery
• age ≥65 years
• expected surgery duration ≥180 minutes
• B-type natriuretic peptide (BNP) >80 ng/L or N-terminal B-type natriuretic peptide (NT-proBNP) >200 ng/L within the last 6 months

Exclusion Criteria:

• emergency surgery
• ambulatory surgery
• planned surgery: nephrectomy, liver or kidney transplantation surgery
• status post transplantation of kidney, liver, heart, or lung
• sepsis (according to current Sepsis-3 definition)
• American Society of Anesthesiologists physical status classification V or VI
• pregnancy
• impossibility to perform cardiac index monitoring using the Starling Fluid Management System (Baxter, Deerfield, IL, USA)
• current participation in another clinical trial or treatment with a similar biological mechanism or primary outcome measure

Start date 12 months after article publication End date: 5 years after article publication

Written request to Principal Investigator

In patients in the routine management group, the treating anesthesiologists will be blinded to data of preoperative baseline cardiac output measurements to avoid performance bias. Participanting patients, outcome assessors, and data analysts are blinded to group allocation.