University of Florida researchers have presented a new theory at the 34th annual Society for Neuroscience on why some anesthesiologists end up abusing drugs.
Dr. Mark Gold, a distinguished professor with UF’s McKnight Brain Institute, said anesthesiologists who sit near a patient’s head during surgery are exposed secondhand to anesthetic drugs as they are exhaled by the patient. Blood sampling and further studies are necessary to determine if anesthesiologists truly suffer ill effects from inhaling trace amounts of the drugs just as nonsmokers are adversely affected by secondhand smoke, Gold said.
“Most people thought that in the evolution of anesthetic practice from inhaled gases — nitrous and ether, and so forth — to drugs that are administered intravenously, there wouldn’t be secondhand exposure,” Gold said. “[Now we see] that those narcotics, which may be 1,000 times more potent than heroin, get into the air, may reach their brain, may change their brain and make it more likely that they’ll crave and want drugs, [become] depressed, and may be more likely that they’ll have a host of behavioral problems.”
Gold said the unintentional exposure may one day be determined to be an “occupational hazard” for anesthesiologists.
Anesthesiologists — who as a group are up to four times more likely to be treated for drug addiction than other physicians — may become sensitized to the intravenous drugs fentanyl and propofol after repeated exposure during long surgical procedures, said Gold, chief of the Division of Addiction Medicine and a professor in the departments of psychiatry and neuroscience.
In 2003, anesthesiologists represented only 5.6 percent of physicians in Florida but accounted for almost 25 percent of physicians monitored for substance abuse, according to Gold’s research. National statistics show a similar overrepresentation for anesthesiologists among drug-abusing physicians.
Gold theorized reasons other than access to drugs caused anesthesiologists to be overrepresented among addicted physicians, and that the presence of analgesic and anesthetic agents in the air in operating rooms might be one of them.
To test the theory, UF researchers initially used sensors developed for the military for detection of nerve gas and explosives. They also used standard analytical equipment called gas chromatography-mass spectroscopy to identify minute quantities of propofol in the exhaled breath of subjects in a clinical trial.
Next, using an analytical device called liquid chromatography-mass spectroscopy-mass spectroscopy, Gold worked with UF anesthesiologists Drs. Donn Dennis, Timothy Morey and Richard Melker to measure and analyze multiple operating room air samples for fentanyl and propofol molecules.
They found the drugs present throughout the operating room, with the largest concentrations over the patient’s mouth. The amounts are so low they can only be detected with recently developed, ultra-sensitive instruments.
“We don’t know what doses they are exposed to at this time,” Gold said. “We will do blood sampling of anesthesiologists to learn that. But fentanyl and related analgesics are very powerful opiates, given in very large doses during cardiac surgery. Anesthesiologists may become sensitized.
“It has been shown that children of smokers are more likely to smoke,” Gold added. “It is currently understood that they have been smoking their whole lives secondhand. So their brain is changing and they are de facto smokers. I believe the same thing happens with anesthesiologists. They had no intention to become addicts, their brains changed, they don’t feel right and they do come to associate the drug with relief.”
Until now, reasons such as family history and access to drugs were considered the main factors leading some anesthesiologists to drug use and addiction, Gold said, but the new findings may change that perception, as well as how recovering anesthesiologists are perceived. It may also lead to changes in air-handling systems, masks and length of shifts in the operating room.
Dr. Mark Aronson, a professor of medicine at Harvard Medical School, said the current theory of easy access to drugs provides a simple explanation for higher levels of addiction among anesthesiologists. However, hospitals monitor drug usage more rigorously now, making access more difficult and the access theory less plausible.
“Gold’s study offers an interesting and certainly plausible alternative explanation and makes the operating room a potentially dangerous occupational hazard for anesthesiologists,” Aronson said. “Obviously this needs further research, but I found this work quite intriguing.”