Newswise — March 3, 2015 – For patients undergoing coronary artery bypass graft (CABG) surgery, the anesthesiologist managing the procedure can have a major impact on the risk of adverse outcomes, according to a study published on January 23rd in Anesthesia & Analgesia.

"The rate of death or major complications among patients undergoing coronary artery bypass graft [CABG] surgery varies markedly across anesthesiologists," according to the report by Dr. Laurent G. Glance of University of Rochester (N.Y.) Medical Center and colleagues. They write, "These findings suggest that there may be opportunities to improve perioperative management to improve outcomes among high-risk surgical patients." The study, previously posted online, appears in the March issue of the journal.

Differences in Outcomes for Different AnesthesiologistsDr. Glance and colleagues used a New York State heart surgery database to study the impact of anesthesiologists on the outcomes of CABG surgery. The analysis included 7,920 patients undergoing isolated CABG (no other procedures performed at the same time) at 23 hospitals in 2009 and 2010. The cases were managed by 91 different anesthesiologists and 97 surgeons.

The study focused on the risk of death or major complications—myocardial infarction, kidney failure, or stroke—occurring in the hospital. Differences in the rate of adverse outcomes between anesthesiologists were adjusted for patient risk factors, heart disease severity, other medical conditions, and hospital quality.

"The variability across anesthesiologists was highly significant," the researchers write. For "low-performing" anesthesiologists (in the bottom one-fourth of performance), the adjusted rate of death or major complications was 3.33 percent. By comparison, for "high-performing" anesthesiologists (in the top one-fourth), the risk of serious adverse outcomes was 1.82 percent.

For patients managed by low-performing anesthesiologists, the adjusted rate of adverse outcomes was about 82 percent higher, compared to those managed by high-performing anesthesiologists. The absolute difference in risk between groups was about 1.5 percentage points. "The performance gap was observed across multiple hospitals and all patient risk groups," Dr Glance and coauthors add.

Can Surgery Be Made Safer by Improving Anesthesia Care?While anesthesia for surgery is generally safe, there is ongoing debate over the true risk of death and serious complications. Counting only very rare complications may create the impression that anesthesia is "safer than it actually is." The researchers write, "However, if more common but still major complications...are caused as much by anesthesia as by surgical management, then surgery can be made safer by further improving anesthesia care."

The researchers note some important limitations of their study, including the inability to fully account for differences in outcomes between surgeons and hospitals. The study also excluded anesthesiologists who had either a low volume of CABG cases or no deaths or major complications—although this is likely to underestimate the differences between anesthesiologists.

The findings show "substantial variability" in death or major complications across anesthesiologists, with close to a twofold difference in risk for CABG patients cared for by low- versus high-performing anesthesiologists. The researchers note that the absolute difference in mortality risk is similar to that reported for high- and low-volume surgeons performing CABG procedures.

"This observation should encourage anesthesiologists and surgeons to increase their efforts to develop evidence-based strategies for improving perioperative care," Dr. Glance and colleagues write. Especially in the era of "Big Data" created by the use of intraoperative electronic medical records, they add, "[I]t should be feasible to create and analyze vast digital libraries of clinical information and use these data to identify best practices in perioperative medicine."

Dr. Steven Shafer, Editor-in-Chief of Anesthesia & Analgesia and Professor of Anesthesiology, Perioperative and Pain Medicine at Stanford University adds “These are very important findings, but they must be considered preliminary until further research helps us understand why performance varies among anesthesiologists. The answer is likely more complex than just differences in clinical skill.”

Read the article in Anesthesia & Analgesia.

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About Anesthesia & AnalgesiaAnesthesia & Analgesia was founded in 1922 and was issued bi-monthly until 1980, when it became a monthly publication. A&A is the leading journal for anesthesia clinicians and researchers and includes more than 500 articles annually in all areas related to anesthesia and analgesia, such as cardiovascular anesthesiology, patient safety, anesthetic pharmacology, and pain management. The journal is published on behalf of the IARS by Lippincott Williams & Wilkins (LWW), a division of Wolters Kluwer Health.

About the IARSThe International Anesthesia Research Society is a nonpolitical, not-for-profit medical society founded in 1922 to advance and support scientific research and education related to anesthesia, and to improve patient care through basic research. The IARS contributes nearly $1 million annually to fund anesthesia research; provides a forum for anesthesiology leaders to share information and ideas; maintains a worldwide membership of more than 15,000 physicians, physician residents, and others with doctoral degrees, as well as health professionals in anesthesia related practice; sponsors the SmartTots initiative in partnership with the FDA; supports the resident education initiative OpenAnesthesia; and publishes two journals, Anesthesia & Analgesia and A&A Case Reports.