Anesthesia in very small kids may raise risk of learning disabilities

By Dr. Ananya Mandal, MDOct 4 2011

According to the latest research very young children exposed to general anesthesia during surgical procedures may be at an increased risk for learning problems.

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 study was commissioned by the US FDA. 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, 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, 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 said.

The study authors write that 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.

This 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 explained.

This new 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.

Results showed that around 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. It was seen that having two or more surgeries requiring general anesthesia was associated with a twofold increase in learning disabilities after considering health status. Children who had two or more surgeries prior to age 2 were also 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.

Dr. Lynne G. Maxwell, pediatric anesthesiologist at the Children's Hospital of Philadelphia, agreed. She said that kids who require multiple surgeries before age 2 usually have serious health problems. “I would hate to have parents who are already worried about a child to feel that they should choose not to have a surgery because of the possible risk of developmental problems,” she said.

University of Vermont associate professor of pediatrics and anesthesia Robert K. Williams in an accompanying editorial says the impact of early exposure to general anesthesia on brain development probably will not be fully understood for years to come. Williams says the new research should alert pediatricians and parents to the issue.

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, agreed that much uncertainty remains. But he said 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…Most surgeries cannot be delayed,” he said.