Down But Not Out
Doctors disagree how best to keep patients from awakening during surgery
The mere mention of waking up during surgery makes anyone who is squeamish want to quickly change the subject. A few anesthesiologists still insist that they've never seen it and it doesn't happen. Most, however, acknowledge that sometimes surgery patients do regain consciousness because their anesthetic medication has fallen too low. Some victims of anesthesia awareness, as this is called, overhear the snappy repartee of the surgical team. Some register a tugging or other physical sensations but without pain. And some feel the agony of every incision, every step of the operation, every stitch. Surgery patients given drugs that immobilize them, as is typical, cannot communicate even with a grunt or a waving finger that they are no longer unconscious. And so the operation proceeds.
That, says Jodie Stanley, a grandmother from Rainbow City, Ala., is what happened to her. Unconscious as she went into hand surgery in January 2004, she suddenly sensed "something cold" on her hand and arm. A nurse herself, Stanley knew she was being painted with an antiseptic solution. "Oh, my gosh," she recalls thinking. "They're getting ready to do surgery on me, and I'm awake." Unable to move, she felt her palm being cut. "I can't expect anybody to understand the pain," says Stanley, age 68. A second incision was made and an instrument was inserted, and after that she remembers nothing. "I must have passed out," she says.
Anesthesiologists have wrestled with the problem for years. Some aggrieved patients argue that most of the risk would be eliminated if anesthesiologists used bispectral index (BIS) monitoring, a brain-wave technology developed by Aspect Medical Systems of Newton, Mass., and approved by the Food and Drug Administration in 1996. But last month, after a year of study, a task force of the American Society of Anesthesiologists issued a draft report concluding that BIS and related techniques are still unproven and the ASA should not recommend them, even for patients at a heightened risk of awareness. The task force could make changes before ASA delegates vote the report up or down at the group's annual meeting in October.
Using a BIS monitor is uncomplicated. Its signature is a brightly displayed number between 0 and 100, representing the patient's relative degree of consciousness according to brain waves picked up by sensors in a disposable forehead strip. Most of the evidence for BIS monitors comes from two large, recent studies, which found that when the number was kept between 40 and 60, as the company recommends, the rate of anesthesia awareness was reduced by 77 percent to 82 percent.
Rebuttal. But many anesthesiologists are unconvinced. They believe their current tools--such as checking levels of exhaled carbon dioxide and anesthetic drugs, monitoring blood pressure and heart rate, and watching for signs of movement--usually are sufficient. They note that both of the recent studies received funds from Aspect Medical. And they cite another study, also funded by the company, which found that a higher percentage of patients with BIS monitors had anesthesia awareness than unmonitored patients did. The purpose of that study, however, was to mount the largest study to date to gauge the frequency of awareness, not to evaluate BIS monitors.
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