Anesthesia for Tots Tied to Learning Deficits

Receiving anesthesia for surgery may have an effect on young brains that puts kids at a long-term cognitive disadvantage, researchers found.

General anesthesia before age 3 years was linked to deficits at age 10 in understanding and using language, as well as poorer reasoning skills compared with unexposed children, according to Caleb Ing, MD, of Columbia University in New York City, and colleagues.

Even a single exposure early in life raised the risk of disability in receptive language 2.41-fold and in cognition 1.73-fold, the group reported in the September issue of Pediatrics.

Most of the general anesthesia exposures were for minor surgical procedures rather than for chronic disease.

Anesthesia should only be used to sedate kids when necessary and using the lowest possible doses, an FDA panel recommended last year.

Although the panel recognized the growing body of evidence for a long-term neurocognitive effect of anesthesia in children whose brains are still developing, it said there wasn’t enough evidence to make a stronger recommendation to parents.

Panelists did suggest that putting off procedures that could be delayed until children are a little older, trying swaddling and sugar water instead for minor procedures, and other alternative strategies should be considered.

The period of peak synapse formation through age 3 years in children appears to be a “window of vulnerability,” according to animal studies.

Those studies have pointed to neurodegenerative changes from apoptosis across types of anesthesia, from drugs like nitrous oxide and ketamine to the benzodiazepines, propofol, and volatile anesthetics.

The researchers examined the Western Australian Pregnancy Cohort (Raine) Study, originally designed to evaluate the long-term effects of prenatal ultrasound.

Among the 2,868 children born from 1989 to 1992 in the birth cohort, 321 received anesthesia by age 3 for diagnostic testing or surgical procedures, most minor. Placement of ear tubes topped the list at 25%.

A battery of neurocognitive tests at age 10 showed significantly poorer scores in tests of receptive (P=0.006), expressive (P=0.004), and total language (P=0.003) on the Clinical Evaluation of Language Fundamentals test for anesthesia-exposed children.

Anesthesia exposed children also showed poorer cognition, with lower scores on Raven’s Colored Progressive Matrices test of abstract reasoning (P=0.002).

These differences had a clinical impact, as the prevalence of disability in language and reasoning were more common in the children exposed by age 3. The adjusted risk ratio risk for any exposure versus none was:

• 1.87-fold for receptive language (95% CI 1.20 to 2.93),
• 1.72-fold for expressive language (95% CI 1.12 to 2.64)
• 2.11-fold for total language (95% CI 1.42 to 3.14)
• 1.69-fold for abstract reasoning (95% CI 1.13 to 2.53)

The directly-administered tests likely were more specific and sensitive than the diagnostic codes, academic performance, standardized testing, school and medical records, and parent and teacher surveys used in prior studies, the researchers noted.

The study didn’t identify a dose-response difference between single and multiple exposures, though one might be found with a larger cohort, the researchers acknowledged.

While a prior observational study had linked early anesthesia exposure to attention deficit hyperactivity disorder, the birth cohort showed no difference in behavior or motor function.

The behavioral analysis was based on parent report, though, and may not have been sensitive enough, the group noted.

The most prevalent volatile anesthetic during the study period was halothane, which is no longer on the market. But its neurotoxic effects in animal studies have been similar to other volatile anesthetics.

Primary source: Pediatrics