The practice of giving oxygen to patients to inhale during a heart attack may not be as beneficial as earlier perceived, scientists now claim.
A new Cochrane Systematic Review says that that giving oxygen may actually increase a patient's risk of dying.
Heart attacks occur when the flow of oxygenated blood to the heart is interrupted. Heart attack patients are often given oxygen to try to improve oxygenation of the heart tissue.
Of the 387 patients involved in the studies, who were given pure oxygen or air to inhale in the 24 hours following the onset of heart attack symptoms, only 14 died, but of these, almost three times as many had inhaled oxygen as opposed to air.
"This result does not necessarily mean that giving oxygen increases the risk of dying from a heart attack," said Dr Amanda Burls of the Department of Primary Health Care at the University of Oxford in Oxford, UK.
"The numbers are so small that this may just have been due to chance."
Dr. Juan Cabello of the Alicante General University Hospital in Alicante, Spain, added, "It is truly amazing how we, as cardiologists, have been employing this treatment without solid evidence."
However, researchers maintain that further studies are needed in order to confirm the theory.