Even a single exposure to anesthesia before age 3 was associated with significantly increased risk for a disability in language and cognition.
Studies on the effects of early exposure to anesthesia on developmental outcomes have yielded mixed results. Most studies suggest adverse effects on development only after multiple exposures in early childhood. Researchers examined this association in a pregnancy cohort of 2608 children in Australia; 321 children had undergone surgical procedures requiring anesthesia before age 3 years.
All children were assessed annually during the first 3 years and at ages 5, 8, 10, 13, and 16 years. Parents recorded their child’s medical history and completed questionnaires about their child’s medical problems, surgeries, and procedures at each assessment. Direct access to medical records was not available. At age 10 years, standardized neuropsychological tests were performed to assess cognition, language, behavior, and motor function. Disability was defined as a score below 1.5 standard deviations from the mean of the entire cohort.
Children who were exposed to anesthesia during the first 3 years had significantly lower scores than unexposed children in receptive and expressive language and abstract reasoning. Exposure to anesthesia was associated with significantly increased risk for a disability in language and cognition after adjustment for demographic factors. This effect was seen in children with a single exposure to anesthesia (206 children) and in those with multiple exposures (52 children). Differences were not found in behavior or motor function.
Comment: A potential adverse effect of early exposure to anesthesia is a reasonable hypothesis (JW Pediatr Adolesc Med May 4 2011). Postnatal brain maturation, particularly the process of synaptogenesis and pruning of neurons, is very active during the first 3 years of life. However, the results of this study should be interpreted with caution. Major limitations include the absence of medical records to substantiate parental histories of surgery and procedures with anesthesia and to identify the type of agent or duration of anesthesia. Further, the database was generated to study outcomes of prenatal ultrasound, not the effects of anesthesia. A study strength is the use of standardized neuropsychological instruments to assess outcomes at age 10 years. These results will likely prompt prospective studies to evaluate the effects of early exposure to anesthesia on specific learning domains and the effects of specific anesthetic agents and duration of anesthesia. When possible, it seems prudent to delay surgery until after age 3 years to reduce risk for neurodevelopmental effects.
Published in Journal Watch Pediatrics and Adolescent Medicine October 10, 2012