There is no evidence that the
common practice of giving patients oxygen to inhale during a heart attack is
beneficial, according to a new study.
Until further research is carried
out, Cochrane Systematic Review researchers say the possibility that giving
oxygen may actually increase a patient’s risk of dying cannot be ruled out.
Globally, more than 30 million
people have heart attacks every year, according to the World Health
Organisation. 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.
However, there is little evidence
that this intervention improves outcomes for heart patients, and some evidence
even suggests it may cause further damage.
The researchers included data from
three trials in their studies. Patients were either given pure oxygen or air to
inhale in the 24 hours following the onset of heart attack symptoms. Of the 387
patients involved in the studies, only 14 died, but of these, almost three
times as many had inhaled oxygen as opposed to air.
Although the results appear to
suggest giving oxygen could do more harm than good, the researchers say there
is not yet enough data to be certain. “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, UK. “The numbers are so small that this may just have been due to
However, Tom Quinn, a professor and
another of the researchers based at the Faculty of Health and Medical Sciences
at the University of Surrey in Guildford, UK, said it is important to resolve
the uncertainty. “Given the fact that this is such a widely used treatment, we
think it is important that a large trial is conducted as soon as possible to
make sure that giving oxygen is not causing any harm.”
Another member of the team, 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.”