Can goal-directed therapy reduce cardiac complications in high-risk surgical patients?

By James E. Barone MD

NEW YORK (Reuters Health) - A new meta-analysis from a group of intensivists at St. George's Hospital in London found that goal-directed therapy (GDT) reduced cardiovascular complications, specifically the incidence of arrhythmias, in high-risk surgical patients.

Goal-directed therapy is the optimization of oxygen delivery by using hemodynamic monitoring and intravenous fluids or vasoactive drugs as needed. Some studies have suggested that perioperative GDT may reduce morbidity and mortality, but it has not been widely adopted.

Two of the authors, Drs. Maurizio Cecconi and Nishkantha Arulkumaran, commented by email to Reuters Health. They said, "Our first question was, is GDT safe? We found that not only it was safe, but also decreased complications."

Dr. Michael P. Grocott is a professor of anesthesia and critical care medicine at University of Southampton, England. He said, "The review is well conducted, and the analysis robust, so the result is clear. The risk is inadvertent bias in choice of selection criteria by individuals very familiar with the literature."

The authors included only randomized controlled trials of GDT on adults that included information about cardiovascular complications such as arrhythmias, acute pulmonary edema, or acute myocardial ischemia.

After identifying 12,398 papers, the search strategy pared the number of suitable studies down to 22 comprising 2129 patients, 275 (12.9%) of whom experienced cardiovascular complications. The most common complication was an arrhythmia, which occurred in 23% of patients with complications, followed by acute pulmonary edema (19%) and acute myocardial ischemia (11%).

Compared to the control group, patients who received GDT had significantly fewer perioperative cardiovascular complications (OR 0.54; p=0.0005). The reduction in cardiovascular complications was driven by the rates of arrhythmias, which were significantly reduced in the GDT cohort (OR 0.54; p=0.007). Rates of acute pulmonary edema and acute myocardial ischemia were not significantly different.

When either normal or supernormal physiologic goals were targeted using minimally invasive cardiac output monitors, significantly fewer cardiovascular events occurred (OR 0.47; p=0.0008). However, when pulmonary artery catheters were used to direct therapy, they were neither beneficial nor harmful (p=0.25).

The clearest benefits of GDT were seen in patients with minimally invasive cardiac output monitoring who received fluids and inotropes in an effort to achieve supranormal oxygen delivery.

The authors said in their email, "No monitor itself can change outcome, however if a monitor is coupled with a protocol applied in the perioperative period, goal-directed therapy can decrease overall complications."

"It is not the monitor that makes the difference, it is the package of care including the clinicians' competent use and interpretation of the monitor and the application of an intervention in response to the information gained," said Dr. Grocott, who co-authored a similar meta-analysis on this subject but was not involved in the current study.

The effect of GDT on mortality or other complications such as acute renal failure were not addressed by this meta-analysis. Some other limitations of the study included the inability to ascertain whether a treatment algorithm or the presence of the monitor itself was the important factor. The goals of therapy were different in each included study, as were the years of study publication and characteristics of the patients and their operations.

The paper appeared online January 10 in the British Journal of Anaesthesia.

"Our results suggest that GDT is safe and previous studies from our group showed that it reduces complications and length of stay, has an effect on long term mortality and is also cost-effective," said Drs. Cecconi and Arulkumaran.

They caution that GDT "is not a magic bullet," but should be part of a 360-degree strategy that goes from proper pre-operative assessment and risk reduction before surgery to optimal recovery after surgery. Used in this context, they believe that anesthesiologists should use GDT for high risk surgical patients.

Dr. Grocott was a bit more restrained. He said, "At present the evidence is quite balanced. There is no convincing harm signal, but there is controversy as to whether the intervention makes no difference or is beneficial." He pointed out that the quality of early studies was poor by today's standards and the overall mortality was much higher. It is therefore uncertain as to whether data from these studies can be generalized to 2014.

SOURCE: http://bit.ly/1ms6Dna

Br J Anaesth 2014.

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