Huge registry shows anesthesia complication rates dropped by more than half in four years

Anesthesia-related complications decreased by more than half in four years, according to the Anesthesia Quality Institute’s (AQI) National Anesthesia Clinical Outcomes Registry (NACOR) of more than 3.2 million anesthesia cases. The results are being presented at the ANESTHESIOLOGY™ 2014 annual meeting.

While the overall mortality rate held steady between 2010 and 2013 (at .03 percent, or 3 deaths per 10,000 surgeries or procedures involving anesthesia), the percentage of adverse events related to anesthesia decreased from 11.8 percent to 4.8 percent of procedures during that time period. The most common minor complication was postoperative nausea and vomiting (35.53 percent), while the most common major complication was medication error (11.71 percent).

“Our goal was to determine the nature and incidence of surgical complications at the national level and to identify their risk factors,” said Jeana E. Havidich, M.D., associate professor of anesthesiology at Dartmouth-Hitchcock Medical Center, Lebanon, N.H. “Previous studies examined adverse events for specific surgical procedures, types of anesthesia or patient populations. This is the first time we’ve been able to look at such a large amount of data on a national level.”

Investigating factors associated with anesthetic complications and near complications is essential for understanding and preventing complications and improving patient safety, said Dr. Havidich. So far, NACOR contains data from about 25 percent of all anesthesia practices in the United States.

Researchers also determined that: Complication rates were not higher in procedures that occurred during evening hours and holidays; patients older than 50 had the highest rates of serious adverse events; and minor complications were more common in healthier patients undergoing elective daytime procedures.

Study coauthor Richard P. Dutton, M.D., M.B.A., AQI executive director, said the study results could be explained in a number of ways.

“Our findings may be the result of changes in the demographics of practices submitting outcomes information to NACOR over time,” he said. “It also could be that outcomes improved in the practices that participate in NACOR’s data gathering.”

Lead study author Adrian Liau, Ph.D., AQI senior research associate, is pleased with the AQI’s progress, but looks forward to further data that will clarify the current results. “As large as our databases are, we only have four years of information so there hasn’t been enough time to definitively gauge the trends we’re seeing,” said Dr. Liau. “Still, we are rapidly building a larger representation of adverse events, and understanding the broad pattern of anesthesia risk through the study of large datasets such as NACOR will help to guide future quality improvement efforts.”