Down But Not Out
Doctors disagree how best to keep patients from awakening during surgery
Some anesthesiologists also complain that electrical disturbances, or artifacts, scramble BIS readings. The surgeon's electrocautery, which burns its way through tissue with an intense electrical current, is one cause. "Some people find that the monitors give them useful information despite the presence of artifacts that throw off the readings," says ASA President Eugene Sinclair, chief of the anesthesia service at Orthopedic Hospital of Wisconsin in Milwaukee, which is in the process of acquiring BIS monitors. "Others find that the presence of the artifacts is a distraction, and these people do not find the monitors helpful."
In a "President's Update" mailing to members when the draft report was released, Sinclair advised keeping an open mind on BIS monitors even if the evidence for their use falls short of conclusive. He and other anesthesiologists in the public eye, he wrote, often are asked: Why not use the technology? "That is a hard question to answer," he wrote. "It is a question each clinician should consider."
Devastating though anesthesia awareness can be, it is unlikely to happen to a particular patient. It does not occur, according to many studies, in 99.8 to 99.9 percent of procedures that involve general anesthesia. But with more than 20 million such operations performed annually in the United States, a 0.1 percent to 0.2 percent incidence generates 20,000 to 40,000 awareness episodes a year--roughly 50 to 100 a day. And patients who need to receive a relatively light dose of anesthetic because of open-heart surgery, severe injuries, organ failure, or certain other reasons face a higher risk of awareness.
Moreover, the studies have looked only at adults. Awareness in children hadn't been seriously considered until earlier this year, when an Australian study in the journal Anesthesia & Analgesia suggested that it might happen four to eight times as frequently as it does in adults. "I don't know if this is or isn't a problem, but as people in this profession, we need to ask whether this is real," says Peter Davis, author of an accompanying editorial and anesthesiologist-in-chief at Children's Hospital of Pittsburgh. One possible factor, noted the study's authors, is that children need higher concentrations of anesthetic drugs than adults do and may receive insufficient anesthetic more often.
Alert. Last October, hospitals got a stern warning on anesthesia awareness from the Joint Commission on Accreditation of Healthcare Organizations, their main credentialing body. In a "sentinel event alert," JCAHO called the problem under-recognized and undertreated and suggested that brain-function monitors--which according to Aspect Medical are used in about 40 percent of all U.S. operating rooms--may help prevent it in patients who are at especially high risk.
The group also cited studies showing emotional distress after such an event. When Stanley woke up in the recovery room and related her experience to the anesthesiologist, "he told me I must have been dreaming," she says. "And I said, no, I felt it, and he said, well, it must have been a reaction to the medications. Then he said I'm sorry, and he walked out."
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