When the heart stops, the lack of oxygen can cause brain damage. So more oxygen is always good, right?

Not always. Here's the story in The Inquirer Wednesday morning.

Patients who have too much oxygen in their arterial blood – so called hyperoxia – after resuscitation from cardiac arrest are more apt to die than similar patient who don't have hyperoxia. The study led by J. Hope Kilgannon of Cooper University Hospital in Camden, N.J. examined the data on 6,326 patients from 120 U.S. hospitals between 2001 and 2005.

Kilgannon and her colleagues found that the 1,156 patients with hyperoxia (18 percent of the total) were significantly more likely to die in the hospital than those with low or normal oxygen levels in their blood.

Getting too much oxygen "was found to be a significant predictor of in-hospital death," the authors wrote in their study which will appear in the Journal of the American Medical Association on Tuesday.

The researchers also found that among those cardiac arrest patients who survived their hospital stay, those with normal blood oxygen levels were more likely to have "independent functional status" compared with those who had hyperoxia.

Check out the full story by my colleague Marie McCullough on this major study in The Inquirer Wednesday.