Study: No short-term neurodevelopmental risk after brief anesthesia in infants | Image Credit: © relif - © relif - stock.adobe.com.

Preliminary results from a randomized clinical trial suggest that brief exposure to inhaled anesthesia during surgery does not lead to adverse short-term neurodevelopmental outcomes in infants and young children, according to findings published in Anesthesiology.¹

The trial, led by Ji-Hyun Lee, MD, PhD, of Seoul National University Hospital, compared 2 approaches to general anesthesia in 400 children under the age of 2 years, undergoing surgery lasting less than 90 minutes. One group received sevoflurane alone, while the other received a “balanced” regimen designed to lower sevoflurane exposure through the addition of intravenous dexmedetomidine and the opioid remifentanil.

At approximately 30 months of age, participants underwent assessments of nonverbal intelligence and parent-reported behavioral outcomes. Investigators analyzed complete data from 343 children and found no meaningful differences in IQ, behavior, or language development between the groups. While the balanced approach "effectively reduced sevoflurane requirements during surgery, it did not provide measurable developmental advantages," said Lee and coauthors, according to a press release.

Authors noted that findings were preliminary, and that full, final results will feature long-term follow-ups at age 5 years, which will include full-scale IQ assessment.

Adding to existing data

Currently, the findings add to existing evidence, including the earlier GAS trial, that single, brief anesthetic exposures are unlikely to cause clinically significant neurodevelopmental impairment. GAS was an international, assessor-masked, equivalence, randomized, controlled trial conducted at 28 hospitals in Australia, Italy, the USA, the UK, Canada, the Netherlands, and New Zealand.²

In GAS, patients were randomly assigned (1:1) to receive either awake-regional anesthetic or sevoflurane-based general anesthetic. The primary outcome measure was full-scale intelligence quotient (FSIQ) on the Wechsler Preschool and Primary Scale of Intelligence, third edition (WPPSI-III), at 5 years of age. Between February 9, 2007 and January 31, 2013, of the 4023 infants who were screened, 722 were randomly allocated, with 50% allotted to each group.

"The median duration of general anaesthesia was 54 min (IQR 41-70)," wrote the investigative team. "The mean FSIQ score was 99·08 (SD 18·35) in the awake-regional anesthesia group and 98·97 (19·66) in the general anesthesia group, with a difference in means (awake-regional anesthesia minus general anesthesia) of 0·23 (95% CI -2·59 to 3·06), providing strong evidence of equivalence."

Previous concerns about potential risks stemmed from animal studies showing possible neurotoxicity of anesthetics in developing brains, which led the FDA in 2017 to issue warnings about repeated or prolonged use in children younger than 3 years.³

“These results provide reassurance for families and clinicians that brief surgical anesthesia is not associated with short-term developmental harm,” wrote Lee and colleagues. "These findings support existing evidence suggesting that brief anesthetic exposure is unlikely to result in clinically significant neurodevelopmental impairment," they added.1

In an accompanying editorial, Andrew Davidson, MBBS, MD, and Caleb Ing, MD, MS, noted the challenges of studying anesthesia safety in young children, particularly given the role of underlying health conditions in neurodevelopment.

Still, they emphasized the value of these preliminary results. “The lack of an effect of differing sevoflurane dose on neurodevelopment may argue against sevoflurane being a cause of neurotoxicity,” they concluded.

References:

1. No sign of toxic effects of inhaled anesthesia in young children. Press release.The American Society of Anesthesiology. Published September 9, 2025. Accessed September 9, 2025.
2. McCann ME, de Graaff JC, Dorris L, et al. Neurodevelopmental outcome at 5 years of age after general anaesthesia or awake-regional anaesthesia in infancy (GAS): an international, multicentre, randomised, controlled equivalence trial. Lancet. doi:10.1016/S0140-6736(18)32485-1
3. FDA Drug Safety Communication: FDA approves label changes for use of general anesthetic and sedation drugs in young children. Updated May 9, 2017. Accessed September 9, 2025. https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-fda-approves-label-changes-use-general-anesthetic-and-sedation-drugs