Whether anesthesia, or surgery, or some combination of the two, have long-lasting effects on the brain of children is an important question which researchers are trying very hard to answer. Three new studies provide some cause for concern.
In a non-clinical, (epidemiologic), study from Columbia University the authors used databases to review cases in which children had hernia surgery in the first four years of life. They found that these children, compared with a control group, had almost twice as much risk of subsequently developing behavioral or developmental disorders.
In a second study, from the Mayo Clinic, the risk of learning disabilities in children after a single anesthetic was not different from a control group but the risk did increase after two or three anesthetics and in the cases where the duration of the anesthetic was longer than 2 hours.
Finally, a Dutch study of children who had urologic surgery. “Neurocognitive” development was evaluated by means of a questionnaire completed by parents. Children who had their procedures before the age of two years had lower scores but the study wasn’t large enough to say with any certainty that this age cut-off is important.
These studies will be presented at the annual meeting of the American Society of Anesthesiologists in October 2008, so the details aren’t available and the studies haven’t been extensively peer-reviewed.
Why did these studies get done?
Previous animal research has shown that anesthesia may harm the developing rat brain. It is not yet known whether this is true for humans. One of the problems in this area of research is that it’s hard to separate the effects of anesthesia from the effects of surgery. Surgery is trauma. Trauma triggers inflammation and other body responses that affect the brain, and other organs. And obviously we cannot do human studies in which surgery is done without anesthesia.
These findings suggest an urgent need to do further research. We need bigger, prospective (forward looking) studies in which children who have surgery and a control group are followed up, and standard methods for assessing neurologic, cognitive and behavioral development are used, rather than administrative databases or questionnaires alone.
What you can do
James Cottrell, at SUNY in Brookly, New York, a well known neuroanesthesiologist recommends that “until and unless we establish that human fetuses and newborns do not suffer anesthetic neurotoxicity” (my emphasis) we should:
- Minimize or avoid anesthesia in the third trimester (last 3 months) of pregnancy
- Delay surgery in preterm and early postnatal infants
- Avoid specific anesthetic agents that seem the most problematic in animal studies (ketamine, nitrous oxide)
- Limit surgical time whenever possible
This advice is easier to issue than to follow. Surgery in the last part of pregnancy or in newborn children is never lightly undertaken. However there are sometimes occasions in which the choice to delay surgery until later in childhood is an option, and these studies should give more weight to a decision to delay when possible.