Targeting a patient’s preoperative resting cardiac index during high-risk abdominal surgery does not improve outcomes and may increase the risk of death, according to findings from a multicenter trial.
The PELICAN Trial Results
Researchers conducted the PELICAN study involving 1,095 patients undergoing elective major abdominal surgery at 12 university medical centers across Europe. To investigate further, Bernd Saugel, MD, from University Medical Center Hamburg-Eppendorf, and co-workers conducted a trial in 1111 patients recruited at 12 university medical centers in Austria, the Czech Republic, Denmark, Germany, and Spain. The primary composite outcome, which included acute kidney injury, acute myocardial injury, severe infectious complications, nonfatal cardiac arrest, or death within the first week, occurred in 44.3% of patients receiving the targeted therapy compared to 46.9% in the routine care group. The difference was not statistically significant, indicating that adjusting treatment based on a preoperative resting cardiac index did not affect early postoperative safety.
Although the main endpoint did not reveal any advantage, the follow-up results were worrisome. In the secondary analysis, death within 90 days occurred in 5.7 % of the 541 individuals who were treated with personalized cardiac-index–directed hemodynamic management, versus 2.8 % of the 540 patients given standard therapy (relative risk = 2.06). Thus, the tailored cardiac-index approach doubled the likelihood of 90-day mortality compared with conventional care.
Why Targeting Cardiac Index May Fail
The overarching premise of preventing organ injury through intraoperative cardiac index–guided hemodynamic therapy is that increasing cardiac index increases oxygen delivery and, thereby, ensures that tissue perfusion and oxygenation meet metabolic demands. However, increasing cardiac index does not necessarily result in increased oxygen delivery. The administration of intravenous fluids may cause hemodilution, which can reduce arterial oxygen content despite an increase in cardiac index. Furthermore, increasing oxygen delivery can improve tissue oxygenation only when oxygen consumption becomes dependent on oxygen delivery.
