News Release

More Americans undergo procedures involving anesthesia outside of O.R.

Registry of more than 18 million patients shows growth driven by minimally invasive procedures and test

Peer-Reviewed Publication

American Society of Anesthesiologists

CHICAGO – More than one-third of Americans who undergo procedures involving anesthesia now have them outside of the operating room (O.R.), an increase of 27 percent in five years, according to an analysis of a large registry being presented at the ANESTHESIOLOGY® 2016 annual meeting. Researchers say these patients tend to be older and in poorer health, having been urged by physicians to have less-risky minimally invasive procedures and tests that don’t need to be performed in an O.R.

“The growth reflects a shift toward safer, less-invasive procedures and tests that still require anesthesia,” said Richard Dutton, M.D., a senior author of the study and chief quality officer for U.S. Anesthesia Partners, Dallas. “Whether inside or outside an O.R., it’s important that anesthesia for patients with severe health conditions is provided by physician anesthesiologists who have the extensive training and skill to deliver safe care.”

The research is based on an analysis of the Anesthesia Quality Institute’s National Anesthesia Clinical Outcomes Registry (NACOR) of anesthesia cases in all settings, from hospitals to freestanding clinics. Researchers identified more than 5.9 million non-O.R. anesthesia cases and 12.4 million O.R. cases from 2010 through 2014 and determined the percentage of cases performed outside the O.R. increased from 28 percent to 36 percent. Non-O.R. patients were an average of 3.5 years older than O.R. patients. Colonoscopy (a screening test for colon cancer) was the most common non-O.R. procedure involving anesthesia.

Procedures that involve large incisions typically take place in an O.R., a sterile environment with extensive specialized equipment, and often are performed under general anesthesia, which makes the patient lose consciousness. Conversely, non-O.R. procedures often are performed by inserting a catheter into an artery, through tiny incisions or using a scope through the mouth or rectum and may be less risky than surgery, particularly for older patients who have heart disease, stroke, severe liver disease or other life-threatening conditions.

Anesthesia provided during non-O.R. procedures is more likely to involve intravenous (IV) sedation that may range from minimal (making the patient drowsy but able to talk) to deep (the patient likely won’t remember the procedure) or regional anesthesia that numbs part of the body. These procedures can be performed in radiological suites or other procedure rooms that don’t feature the same extensive equipment as the O.R.



Founded in 1905, the American Society of Anesthesiologists (ASA) is an educational, research and scientific society with more than 52,000 members organized to raise and maintain the standards of the medical practice of anesthesiology. ASA is committed to ensuring physician anesthesiologists evaluate and supervise the medical care of patients before, during and after surgery to provide the highest quality and safest care every patient deserves.

For more information on the field of anesthesiology, visit the American Society of Anesthesiologists online at To learn more about the role physician anesthesiologists play in ensuring patient safety, visit Join the ANESTHESIOLOGY® 2016 social conversation today. Like ASA on Facebook, follow ASALifeline on Twitter and use the hashtag #ANES2016.


LaSandra Cooper
Senior Public Relations Manager
American Society of Anesthesiologists
O: (847) 268-9106
C: (708) 650-2886

Amanda ReCupido
Public Communications Inc.
O: (312) 558-1770
C: (847) 445-2360

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.