Oxygen during CPR improves survival

Washington, Dec 1 (ANI): Although it is said that people can survive cardiac arrest if they receive only chest compressions during cardiopulmonary resuscitation, Ohio researchers insist at some point there arises a need to add oxygen.

Lead researcher Mark Angelos said his research is not intended to counter the current guidelines of American Medical Association, instead, scientists continue to study the intricacies of the resuscitation process in the pursuit of ways to improve the potential for survival after cardiac arrest.

Scientists tested different scenarios in an animal study of cardiac arrest.

The rats received either 100 percent oxygen, 21 percent oxygen - the equivalent of room air - or no oxygen (100 percent nitrogen) at the same time they received cardiopulmonary resuscitation (CPR).

They found that about 80 percent of the rats survived regardless of the percentage of oxygen they received along with chest compressions.

However, in the group receiving no oxygen, only one animal could be resuscitated.

"The study showed that there is a need for oxygen. How much oxygen is needed remains unknown. There is probably a sweet spot in there somewhere," said Angelos, professor of emergency medicine at Ohio State University and senior author of the study.

"For the first few minutes, it's probably right just to push on the chest. But at some point you probably need to add oxygen, however you can - maybe mouth-to-mouth or with supplemental oxygen. Where that sweet spot is is not yet clear," he added.

Neurological tests showed that five of seven of the room-air rats and three of eight of the rats on 100-percent oxygen during CPR returned to normal brain function at 72 hours.

The researchers considered these findings secondary to the initial finding that oxygen was required for success during the initial resuscitation process, Angelos added.

"In a public setting, presumably we don't have any options. We see that ventilating with room air is just as good as supplemental oxygen," he said.

"However, we also know now that too little or the absence of any ventilation might be harmful, at least over time, due to the lack of oxygen," he added.

The research is published in a recent issue of the journal Resuscitation. (ANI)