It sounds like grist for a lurid movie, and indeed last fall, Awake explored this notion of patients waking up, paralyzed, while under general anesthesia. But the episodes above, though highly unusual, are all too real, as described today in the august pages of the New England Journal of Medicine.

For many hospitals, the answer to this "anesthesia awareness" is to use a brain monitor so doctors can give more drugs to patients who seem to be awaking. Yet the new study, which sought to gauge the effectiveness of the most common such device, found it might not reduce this risk at all.

The manufacturer of that brain-monitoring technology, called Bispectral Index (BIS), disputed the researchers' interpretation.

And anesthesiology chiefs at three Philadelphia-area hospitals, none involved with the study, said the results would not keep them from using the device. They said it also helped them on the other end of the spectrum - making sure they do not administer too much anesthetic.

At Drexel University, meanwhile, engineers and physicians are trying to develop a better device, one that uses near-infrared light to measure changes in oxygen levels in the brain's prefrontal cortex. The team is presenting its findings at a conference this month in San Francisco.

The BIS "is a good monitor," said Jay Horrow, chairman of the anesthesiology department at Drexel's College of Medicine. "We think we can do better."

One thing is clear: Although some physicians have been known in the past to dismiss reports of awareness as simply a bad dream, the consensus is that it exists.

Anesthesia awareness - regaining some level of consciousness during surgery - is thought to occur in perhaps one or two out of 1,000 surgical patients in the United States, a total of 20,000 to 40,000 cases a year. The bulk of them do not feel pain.

Still, for some it is so disturbing that they suffer from post-traumatic stress disorder and must undergo counseling.

For general anesthesia, patients typically are given a mix of drugs - including one to "knock them out" and often another called a paralytic.

This relaxes the muscles to make surgery easier. But in the rare case that a patient starts to wake up - not able to speak - the paralytic effect can be horrifying.

One patient in the study reported that when a tube was inserted into his throat, he felt as if he "needed to fight for my life."

Another patient, a 22-year-old woman, said she remembered wanting to gag but felt unable to move.