How might anesthesia at a very young age affect children as they grow up? University of Vermont (UVM) Associate Professor of Anesthesiology and Assistant Professor of Pediatrics Robert Williams, M.D., and colleagues, developed a database that compares spinal anesthesia response data from more than 2,500 Vermont babies with standardized test scores and other data from the Vermont Department of Education to try to understand whether anesthesia exposure early in life affects cognitive function later on. Not only is Williams’ research helping to understand more about this connection, but the method of analyzing education data in tandem with medical data shows promise as a model for future studies.
In a paper in the June 20 issue of the journal Anesthesia and Analgesia, Williams and six colleagues from UVM and Fletcher Allen Health Care start to hone in on whether or not choice of anesthetic technique in infants has neurodegenerative effects and answers the question: Do these children – who have all received the same type of anesthesia - show achievement gaps relative to a control group? The study looks specifically at babies who received spinal anesthesia, as recorded in the Vermont Infant Spinal Registry – a robust database that grew from records kept by Professor of Anesthesiology Emeritus J. Christopher Abajian, M.D. – which notes response to spinal anesthesia and other information from medical records dating back to the late 1970s.
With data from the Vermont Department of Education, which keeps records on standardized test scores for all Vermont children, the group analyzed records for 265 students who had a single exposure to spinal anesthesia during infancy. They compared these former patients to a control group matched by “grade, gender, year of testing, and socioeconomic status.” A de-identified, integrated medical, and educational research (DIMER) database was created that cross-referenced educational data, including math and reading standardized test scores, with the patient records.
The study “found no link between duration of surgery with infant spinal anesthesia and scores on academic achievement testing in elementary school.” It also found “no relationship between infant spinal anesthesia and surgery with very poor performance on elementary school achievement testing.”
The results are particularly interesting when compared to an Iowa-based study on elementary school children, published in Anesthesiology in July 2012, which demonstrated an association between the duration of the anesthesia and diminished test scores in children exposed to a single general anesthesia during the first year of life. A smaller group of children in the same study showed “very poor academic achievement.”
Does this mean spinal anesthesia – as opposed to general anesthesia – is the better choice for infants when it comes to cognitive function later in life? The results are “provocative, but not definitive,” Williams says. The research overall is less than conclusive, with several other studies showing anesthesia exposure having no effect on cognitive ability. Animal studies have revealed an “indisputable relationship” between early anesthesia exposure and learning disabilities later in life, but no research has demonstrated the same link in humans.
One challenge lies in separating the effect of the anesthetic from other confounding factors. “It could be something else in their lives, or it could be the surgery,” Williams says.
In regards to his own study, Williams notes one limitation – the lack of a control group who received general anesthesia. The study also did not account for other variables that may affect test scores, including prematurity, health status, birth weight and maternal education. Nevertheless, the study by Williams and colleagues serves as a model for further research, and plans are in place to conduct a second study in cooperation with Dartmouth-Hitchcock Medical Center in New Hampshire, says Williams. Since Dartmouth uses general anesthesia, the goal would be to compare education data from Vermont children who undergo surgery there with infants at Fletcher Allen who receive spinal anesthesia. Williams says setting up a partnership with the New Hampshire Department of Education is a possibility.
Williams’ co-authors on the Anesthesia and Analgesia article include H.W. “Bud” Meyers, Ph.D., a former Vermont deputy commissioner of education and current director of the UVM Jeffords Center for Policy Research and associate professor of education; Diantha Howard, M.S., a bioinformatics expert at the Vermont Center for Clinical and Translational Science; Ian Black, M.D., and David Adams, M.D., both UVM associate professors of anesthesiology; Donald Mathews, M.D., professor of anesthesiology; and Alexander Friend,research specialist in anesthesiology.
Link to an abstract of the study article here.