Oct. 3, 2011 -- There are new concerns about an increased risk for learning problems in very young children exposed to general anesthesia during surgical procedures.
Researchers from the Mayo Clinic in Rochester, Minn., found a twofold increase in learning disabilities in children who had more than one exposure to general anesthesia with surgery before age 2.
The study is published in the November issue of Pediatrics.
The FDA requested and funded the study. Last spring, an FDA panel met to review the research examining the effect of early exposure to anesthesia on the developing brain.
Following the meeting, FDA director of anesthesia and analgesia products Bob Rappaport, MD, wrote that additional studies are needed. He noted that "at present, there is not enough information to draw any firm conclusions" about the long-term impact of early exposure to general anesthesia on the brain.
The new study adds to the evidence linking repeated exposure to general anesthesia very early in life to an increased risk for learning disabilities, but it does not prove the link, says Randall Flick, MD, who led the Mayo research team.
"I fully support the FDA's conclusion that we do not yet have sufficient information to prompt a change in practice," he tells WebMD.
Anesthesia and the Developing Brain
Each year in the U.S., millions of babies and toddlers have surgeries that require general anesthesia. These surgeries range from lifesaving operations to elective procedures.
Studies in rodents and monkeys have repeatedly shown that exposure to anesthesia at a very young age kills brain cells.
In 2009, Flick and colleagues reported that children exposed to general anesthesia during surgery on two or more occasions before age 4 had a twofold increase in learning disabilities when they reached school age.
Their latest research expands on this work by considering the potential impact on brain development of the illness that made the surgery necessary in the first place, Flick says. One criticism of the earlier work, he says, was that the role of other existing illnesses was not taken into account.
"Sick children have more learning disabilities and sick children require more surgeries," Flick says.
The study included 1,050 children born between 1976 and 1982 in a single school district in Rochester, Minn., enrolled in a larger health study.
A total of 350 children who had one or more surgeries requiring general anesthesia before age 2 were compared to 700 children with no such history.
Among the major findings:
- About 37% of children who had had multiple surgeries requiring general anesthesia before age 2 had learning disabilities, compared to 24% of children who had just one surgery and 21% of children who had no surgeries.
- After factoring in the impact of health status, having two or more surgeries requiring general anesthesia was associated with a twofold increase in learning disabilities.
- Children who had two or more surgeries prior to age 2 were three to four times as likely to have been identified by their schools as needing special help for language and speech difficulties through an individualized education program (IEP) mandate.
Should Elective Surgery Be Delayed?
Although he calls the animal data compelling, University of Vermont associate professor of pediatrics and anesthesia Robert K. Williams, MD, says the impact of early exposure to general anesthesia on brain development probably will not be fully understood for years to come.
"It is very likely that we will be living with quite a bit of uncertainty about this for some time to come," he tells WebMD. "Trying to sort this out in humans is really hard because we are talking about subtle effects that may not show up until a child is well into school age."
Williams says the new research should alert pediatricians and parents to the issue.
"Whenever surgery is proposed on a small child -- or for that matter sedation for other reasons, including MRI scanning -- we need to make sure the procedure is truly indicated," he says. "If the answer is 'yes,' the question becomes, 'Can surgery be delayed until a later age without causing harm?"
In an editorial published with the study, Williams also recommended the use of local anesthesia when appropriate, noting that a local spinal anesthetic can be safely used for procedures such as circumcision and hernia repair.
Pediatric surgeon Kevin P. Lally, MD, agrees that much uncertainty remains. But he says parents should not lose sight of the fact that surgeries often save the lives of very sick babies.
Lally chairs the American Academy of Pediatrics section of surgery. He also chairs the department of pediatric surgery at the University of Texas Medical School, Houston.
"It might be appropriate to delay a truly elective surgery, but they represent only a small percentage of procedures in very young children," he says. "Most surgeries cannot be delayed."