(RxWiki News) Standards for the length of time cardiopulmonary resuscitation should be performed vary, though recent research had suggested a longer period of up to three minutes could be beneficial.
A large-scale study has shown that extending the amount of time that firefighters and paramedics perform CPR from one minute to three minutes doesn't provide any benefit to patients.
"Learn CPR so you are prepared during an emergency."
Dr. Ian Stiell, a senior scientist at the Ottawa Hospital Research Institute, chair of emergency medicine at the University of Ottawa and a physician in The Ottawa Hospital Emergency Department, said new research definitively shows there is no advantage to a longer period of initial CPR.
He said the study also suggested that patients may fare better receiving a shorter period of CPR from a paramedic as opposed to CPR from a bystander.
Each year more than 350,000 in the United States and Canada suffer from sudden cardiac arrest, but less than 10 percent survive. CPR helps increase blood flow to the brain for such patients, but is generally only used for a short period while medics prepare defibrillators, which can restart the help by electrical shock.
Researchers collected data from 10,000 cardiac arrest patients from 10 North American regions, making the study the largest randomized cardiac arrest trial in the world.
Paramedics and firefighters were divided into groups with one group instructed to provide CPR for 30 to 60 seconds, and the second asked to perform CPR for three minutes. Halfway through the study, the groups switched the CPR time frames.
No differences were found between the two groups. For each group, 5.9 percent of patients survived in satisfactory health at hospital discharge.
But with a closer analysis of the amount of time that CPR was given, it was discovered that survival had a tendency to decrease as the length of initial CPR increased in patients who received it from a bystander. About 10 percent of study patients had received CPR from a bystander.
"The Resuscitation Outcomes Consortium studies are essential to refining the science of resuscitation and will help save more lives," said Manuel Arango, director of Health Policy for the Heart and Stroke Foundation of Canada. "This knowledge furthers our understanding of optimal resuscitation techniques and will help inform the next Heart and Stroke Foundation Emergency Cardiac Care guidelines."
The research was published in the New England Journal of Medicine.