The first rule now in such cases is to keep blood oxygen levels high by whatever means possible, Grocott noted. "But mechanical ventilation can be harmful," he said. "It can cause inflammation in the lungs. The gentler you are, the less damage you do to the lungs."
The data from the Everest study is not nearly enough to be put to use medically, Grocott said. "We are not proposing a change in clinical practice," he said. But he added that it was enough to spur a proposal for a randomized clinical trial of less aggressive oxygen-supplying treatments in some cases.
"We are currently seeking funding for such a trial in the United Kingdom," he said. "We would do the trial in people at lowest risk to hypoxia, not to those with heart attack and stroke. It would be in younger people with no vascular [blood vessel] disease, traumatically injured patients with injured lungs."
But what is seen in Everest climbers might not be true in the emergency room, said Dr. Norberto C. Gonzalez, professor of molecular and integrative physiology at the University of Kansas, who has done research on hypoxia.
The climbers in the study had spent substantial amounts of time at high altitudes, Gonzalez said. "These people are acclimatized," he said. "If you and I were exposed to this level of oxygen, we couldn't take it."
While he expressed marvel at the measurements, "as low in oxygen as you can get and still be alive," Gonzalez expressed doubt that the findings seen in experienced climbers could be extended to ordinary hospital treatment.
"I'm not so sure that you can extrapolate what happens to a healthy individual who is exposed to an extreme to someone who has many problems," he said.
What hypoxia can do to the brain is described by the U.S. National Institute of Neurologi
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