harrisonsdream
03-30-2007, 11:50 PM
Anesthesia risks for children feared
Experiments on animals find drugs harmful to developing brains
By ANDREW BRIDGES
Associated Press
WASHINGTON — Anesthesia can be harmful to the developing brain, studies on animals suggest, raising concerns about potential risks in putting young children under for surgery.
Food and Drug Administration scientists stressed Thursday they have no evidence that anesthesia and sedation drugs, which have been commonly administered for decades, can cause brain damage in children.
But numerous animal studies find that a majority of the drugs typically used to knock out children before surgery do kill brain cells in young rats, mice and — preliminary results suggest — rhesus monkeys.
"A safety signal has been identified in animals for many drugs used to provide sedation and anesthesia. This database is growing. The relevance of the animal findings to pediatric patients is unknown," Dr. Arthur Simone, an FDA medical officer, told experts gathered by the agency to discuss the issue.
Experiments on laboratory rats and other animals have shown that the drugs can lead to subtle but prolonged changes in behavior, including memory and learning impairments, according to a study published by FDA scientists this month in the journal Anesthesia & Analgesia.
Scientists don't know if those study findings apply to children. Nor have comparable human studies been done that might provide answers.
Even detecting the effect of ketamine, halothane and other anesthetics on the central nervous system is difficult if not impossible in the young, according to the FDA. Unlike, say, fetal alcohol syndrome, there is no clear-cut collection of disorders associated with anesthesia, said Dr. Bob Rappaport, head of the FDA's anesthesia office.
The FDA published the study and convened a public meeting to alert other experts to its concerns, as well as to update them on research and outline tentative plans for future studies.
Some drugs appear to cause more harm to animals than others, the FDA and other experts said. Furthermore, in some drugs both dose size and duration may affect the brain differently. And some combinations of drugs — like the triple "cocktail" of isoflurane, midazolam and nitrous oxide — may be more toxic to the brain than any one used individually.
In humans, that period of rapid brain growth begins before birth, in the third trimester, and extends to about age 3.
Experiments on animals find drugs harmful to developing brains
By ANDREW BRIDGES
Associated Press
WASHINGTON — Anesthesia can be harmful to the developing brain, studies on animals suggest, raising concerns about potential risks in putting young children under for surgery.
Food and Drug Administration scientists stressed Thursday they have no evidence that anesthesia and sedation drugs, which have been commonly administered for decades, can cause brain damage in children.
But numerous animal studies find that a majority of the drugs typically used to knock out children before surgery do kill brain cells in young rats, mice and — preliminary results suggest — rhesus monkeys.
"A safety signal has been identified in animals for many drugs used to provide sedation and anesthesia. This database is growing. The relevance of the animal findings to pediatric patients is unknown," Dr. Arthur Simone, an FDA medical officer, told experts gathered by the agency to discuss the issue.
Experiments on laboratory rats and other animals have shown that the drugs can lead to subtle but prolonged changes in behavior, including memory and learning impairments, according to a study published by FDA scientists this month in the journal Anesthesia & Analgesia.
Scientists don't know if those study findings apply to children. Nor have comparable human studies been done that might provide answers.
Even detecting the effect of ketamine, halothane and other anesthetics on the central nervous system is difficult if not impossible in the young, according to the FDA. Unlike, say, fetal alcohol syndrome, there is no clear-cut collection of disorders associated with anesthesia, said Dr. Bob Rappaport, head of the FDA's anesthesia office.
The FDA published the study and convened a public meeting to alert other experts to its concerns, as well as to update them on research and outline tentative plans for future studies.
Some drugs appear to cause more harm to animals than others, the FDA and other experts said. Furthermore, in some drugs both dose size and duration may affect the brain differently. And some combinations of drugs — like the triple "cocktail" of isoflurane, midazolam and nitrous oxide — may be more toxic to the brain than any one used individually.
In humans, that period of rapid brain growth begins before birth, in the third trimester, and extends to about age 3.