The Department of Anesthesiology at the Mount Sinai Health System
Repeated exposure to anesthesia early in life causes changes in emotional behavior that may persist long-term, according to new research from the Icahn School of Medicine at Mount Sinai.
The findings, published in the August 2015 Online First edition of Anesthesiology, mark the first time nonhuman primates have been found to experience long-term behavioral changes resulting from repeated postnatal exposure to anesthesia. Prior results have shown that baby rodents also experience cognitive impairments later in life stemming from early anesthesia exposure.
The study was conducted in the absence of other factors and comorbidities that are associated with anesthesia and surgery, and done in collaboration with researchers at the Yerkes National Primate Research Center at Emory University.
Newborn rhesus monkeys, which have comparable brain growth to human babies, were used to carry out the controlled studies. Seven days after birth, and again two weeks and four weeks later, ten rhesus monkeys were exposed to a common anesthetic procedure that is used on pediatric patients during surgery.
Researchers then evaluated the socio-emotional behavior of the exposed subjects at six months of age and compared it with that of healthy controls by introducing both groups to a mild social stressor, an unfamiliar human. They found the anesthesia-exposed infant monkeys were significantly more anxious than the control group when confronted by the unfamiliar human.
“Our results confirm that multiple anesthesia exposures alone result in emotional behavior changes in a highly translational animal model. This raises concerns about whether similar phenomena are occurring during clinical anesthesia exposure in children,” says Mark Baxter, PhD, Professor of Neuroscience, and Anesthesiology, at Icahn School of Medicine at Mount Sinai, and senior author of the study.
The findings are part of a larger longitudinal study that will identify the mechanisms by which anesthetics cause long-term changes in the central nervous system and impact behavior; and the length of time emotional changes persist and whether they resolve over time.
According to Dr. Baxter, future studies may also lead to the development of a new anesthetic agent or prophylactic treatment to counteract the impact of anesthesia on behavior in children.