Link Discovered Between Anesthesia Exposure and Learning Disabilities in Children

Children who require multiple surgeries under general anesthesia (GA) during their first three years of life are at higher risk of developing reading, written language, and math learning disabilities (LD) later on in life, claims a new study.

Researchers at the Mayo Clinic (Rochester, MN, USA) conducted a population-based, retrospective birth cohort study by examining the educational and medical records of all children born to mothers residing in five townships of Olmsted County (MN, USA), from 1976 to 1982, and who remained in the community at 5 years of age. Hazard ratios were calculated for anesthetic exposure as a predictor of LD, adjusting for gestational age at birth, sex, and birth weight. The children in the study were tested as a natural part of the educational process in the Rochester school system.

The researchers found that 593 of the children received GA before age four; the GA chemicals in use during the study period were primarily halothane and nitrous oxide (NO2, "laughing gas"). Compared with those not receiving anesthesia, a single exposure to anesthesia was not associated with an increased risk of LD. However, children receiving two anesthetics or more anesthetics were at almost double the risk of being identified as having a learning disability before age 19; the risk also increased with longer cumulative duration of anesthesia exposure. The study was published in the April 2009 issue of Anesthesiology.

"The problem is that anyone who underwent an anesthetic also had surgery," said lead author anesthesiologist Robert Wilder, M.D., Ph.D. "It's unclear whether it's the anesthetic, the physiological stress of surgery, or perhaps the medical problems that made surgery necessary that are responsible for the learning disabilities."

"It's very important for parents and families to understand that although we see a clear difference in the frequency of learning disabilities in children exposed to anesthesia, we don't know whether these differences are actually caused by anesthesia," said study coauthor anesthesiologist Randall Flick, M.D. "Parents and physicians need to balance this information along with the normal decisions that we all go through when we decide to have surgery for one of our children. Certainly, performing surgery without appropriate use of anesthesia is unacceptable."

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