Anesthesia and Subsequent Neurodevelopment

Anesthesia.  Been around seemingly forever.  We have a pretty good handle on it regarding adults.  So there’s no need to question its safety for young children when adjusted by body weight and other factors to appropriate pharmacologic doses, correct?  After all, what we’re concerned about primarily is death.  As long as a young child doesn’t die from anesthesia, what’s the risk?

Hadn’t really given it all that much thought until last week, when we were sharing a delightful dinner with our friends Bob & Linda visiting from CA, and the conversation turned to strabismus surgery in childhood.  We know that certain surgical procedures aren’t elective, and the need for anesthesia outweighs any potential risks.  There have been reports around for awhile that children under the age of three who require multiple surgeries under anesthesia prior to age three are more at risk for subsequent learning disabilities.  Of course one could argue that the requirement for multiples surgeries means that the child has developmental challenges that will predispose them to subsequent LD, and the link to anesthesia is association not causation.  But even the effects of anesthesia during labor have attracted attention in terms of potential neurotoxicity through the placenta and subsequent developmental effects.  An article in the British Journal of Anaesthesia a couple of years ago suggested this bears closer scrutiny, and proposed this conceptual model.

With that background comes this eye-opening conclusion from an article published recently in the journal Pediatrics:

“In this birth cohort, children exposed to anesthesia before age 3 had an increased long-term risk of clinical deficit in receptive and expressive language, as well as abstract reasoning. Children who only had a single exposure to anesthesia also had an increased risk of deficit in receptive language and abstract reasoning. Our results indicate that the association between anesthesia and neurodevelopmental outcome may be confined to specific domains. Our study documented specific deficits obtained through directly administered neuropsychological assessment. This is in contrast to earlier studies finding no evidence of an association using broad-based summary scores, but in line with more recent data finding exposure to anesthesia associated with learning disability and receipt of individualized education programs for speech/language impairment.^{13,15,16,19,20} Our findings may play an important role in directing future studies by identifying deficits in specific neuropsychological domains associated with anesthetic exposure. It is also noteworthy that the outcomes of language and reasoning cannot be easily assessed in the animal model, which emphasizes the importance of studies in humans.”

I am not anti-surgery, but there is now sufficient evidence that this issues should be presented as a potential risk factor in considering strabismus surgery under general anesthesia for young children.  It is an elective procedure in many instances.  And if the risk on subsequent neurodevelopment outweighs the potential benefits for one procedure, yet alone multiple procedures (and the multiplicative effects have never been studied to my knowledge) – then this issue warrants more serious consideration.  At the very least, it should be part of the informed consent discussion, along with other potential risk factors.