Newswise — CHICAGO – Children who are exposed to general anesthesia from birth to age 2 have developmental testing results in kindergarten that are similar to those of children who have not been exposed, according to a new study published in the October issue of Anesthesiology, the official medical journal of the American Society of Anesthesiologists (ASA).

The study provides some reassurance that exposure to general anesthesia in young children is not associated with significant long-term effects on the growth and development of the brain, according to the researchers. Every year, millions of children require general anesthesia to undergo surgical or diagnostic procedures. Although exposure to anesthetics in the developing brains of animals has been linked to abnormalities in behavior, learning and memory, the effect in human children is unclear. Results have varied, but the combined analysis of previous studies in humans suggest that although a single anesthetic exposure might be safe, multiple exposures may be associated with increased risk, the authors note.

The new study compared the results of developmental testing in kindergarten in more than 4,000 children exposed to general anesthesia before the age of 4 with those of more than 13,000 children who had not been exposed.

The researchers found that developmental testing results did not differ in children exposed to either single or multiple anesthetics from birth to 2 years, the period assumed to be of greatest risk. Children exposed to a single anesthetic from 2 to 4 years showed small deficits in testing in language and cognition. However, multiple exposures from age 2 to 4 were not associated with greater risk. These new results are corroborated by another large observational trial previously published in Anesthesiology that was conducted independently. These findings refute the previously held assumption that the earlier and more times a child is exposed to general anesthesia, the greater the likelihood of long-term risk to brain development, researchers wrote.

“These results suggest that the concerns raised by animal studies may not be directly applicable to children,” said Ruth Graham, M.D., study lead author, Department of Anesthesia, University of Manitoba in Winnipeg, Canada. “Rather, the combination of biological and social factors that are responsible for the need for surgery and anesthesia may also account for the small deficits seen in the developmental testing in kindergarten in the 2- to 4-year-old age group.”

“Although further research is required to elucidate the specific factors responsible for the findings seen in 2- to 4-year-old children, this study adds to the growing body of literature that exposure to general anesthesia in very young children is not associated with significant neurodevelopmental concerns,” said Dr. Graham.

SmartTots, a public-private partnership between the U.S. Food and Drug Administration and the International Anesthesia Research Society, is coordinating and funding research with the goal of ensuring safe surgery for the millions of infants and young children who undergo anesthesia and/or sedation each year. Last year, SmartTots, in partnership with the ASA, released a consensus statement on the “Use of Anesthetic and Sedative Drugs in Infants and Toddlers,” which urges health care providers, patients and caregivers to discuss the timing of planned procedures and to evaluate each child’s care individually based on age, type and urgency of the procedure and other health factors.

THE AMERICAN SOCIETY OF ANESTHESIOLOGISTSFounded 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 that physician anesthesiologists evaluate and supervise the medical care of patients before, during, and after surgery to provide the highest quality and safest care that 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 # # #