Furthermore, the researchers found, the use of this regimen to produce general anesthesia appears to improve the oxygenation of the fetal brain, according to their novel system for measuring cerebral oxygenation in the developing fetus.
These findings are an important step toward better understanding this issue, the researchers said, since a study in new-born rats published in 2003 reported that exposure to various anesthetic agents caused neurodegeneration in the developing rat brain. However, the Duke researchers said that the current study may be more realistic, since it is was conducted under circumstances that more closely parallel that which humans would experience.
"The results of this investigation suggest that the moderate inhalation anesthetic exposure during pregnancy may not be deleterious to the fetus," said lead researcher James D. Reynolds, Ph.D., research director of women's anesthesia at Duke. The results of the Duke study were published March 9, 2005, as an advanced on-line publication of the Journal of Cerebral Blood Flow and Metabolism.
"These types of studies are very difficult to conduct in humans, since you can't do the invasive type of monitoring you can in animal models, and it is difficult to separate the effects of the anesthesia from the underlying reasons for the surgery," Reynolds said. "So we felt that in order to come as close as possible to what might be expected in humans, we had to do something new."
General anesthesia, which typically involves a combination of drugs, renders the patients temporarily unconscious during the surgery.
The earlier study -- the results of which led to much discussion in the anesthesia community -- involved putt
Contact: Richard Merritt
Duke University Medical Center