Saturday science subject: Life after 'death'


— 5:08 PM on May 5, 2007

Common medical knowledge dictates that after a few minutes of "clinical death," whereby a person's heart is no longer beating, that person is unlikely to be successfully resuscitated. The conventional reasoning behind this knowledge is that oxygen-starved cells in the person's brain and heart die after a few minutes, causing irreparable damage to those organs. However, as MSNBC reports, new research suggests those cells don't actually die after a few minutes of oxygen starvation. In fact, MSNBC quotes Dr. Lance Becker from the University of Pennsylvania as saying the cells may take hours to die:

That dogma went unquestioned until researchers actually looked at oxygen-starved heart cells under a microscope. What they saw amazed them, according to Dr. Lance Becker, an authority on emergency medicine at the University of Pennsylvania. "After one hour," he says, "we couldn't see evidence the cells had died. We thought we'd done something wrong." In fact, cells cut off from their blood supply died only hours later.

But if the cells are still alive, why can't doctors revive someone who has been dead for an hour? Because once the cells have been without oxygen for more than five minutes, they die when their oxygen supply is resumed. It was that "astounding" discovery, Becker says, that led him to his post as the director of Penn's Center for Resuscitation Science, a newly created research institute operating on one of medicine's newest frontiers: treating the dead.

The research suggests common treatment for people who, say, collapse in the street from cardiac arrest is backwards. When they reach the ER, they're given oxygen, which is precisely the catalyst that causes cell death. Instead Dr. Becker says, "We should aim to reduce oxygen uptake, slow metabolism and adjust the blood chemistry for gradual and safe reperfusion."
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