(RxWiki News) If someone goes into cardiac arrest, a bystander's knowledge of CPR could save their life. A new study addresses how to improve the chances of recovery.
This study looked at thousands of patients who had cardiac arrest and received CPR. The researchers compared the time it took from the beginning of the episode until the person's heart started beating naturally again.
The study's results showed that people whose heartbeat returned earlier were more likely to be alert and recovering well in the month after the cardiac arrest episode.
The researchers suggested that bystanders should perform CPR for at least 38 minutes to help ensure a more successful recovery.
"Find CPR training courses in your area."
Ken Nagao, MD, PhD, of the Surugadai Nihon University Hospital, led this study on CPR.
CPR, or cardiopulmonary resuscitation, is used on people who are having cardiac arrest, a condition in which the heart stops beating.
CPR involves pushing on the chest at a rate of 100 compressions per minute. Sometimes, people performing CPR also push air into the patient's lungs.
The procedure helps blood to continue pumping through the heart and the body when the heart is not working on its own. Pushing blood throughout the body helps delay or lessen damage to tissues and organs until the patient can receive more extensive medical care.
If a person has a cardiac arrest, CPR is usually performed until the person has spontaneous circulation or their heart starts beating on its own again.
This study looked at data on people who had been resuscitated after cardiac arrest. The researchers looked at the relationship between health after the event and the length of time it took for the person's heart to start beating naturally again.
The researchers used the All-Japan Utstein Registry, which kept track of cardiac arrests outside of hospitals between 2005 and 2011.
Specifically, they looked at adults who had experienced cardiac arrest, who received CPR from a bystander and whose hearts began beating again before they arrived at the hospital.
The researchers noted whether the patients were alert and functioning well one month after the event, or whether they had moderate or severe disability.
Of the 284,814 patients in the registry who had experienced cardiac arrest, 31,845 had resuscitation care that helped their heart beat naturally again before they reached the hospital.
Of those patients, 8,714 (27.4 percent) had a favorable neurological outcome; that is, they were only mildly or moderately disabled by the cardiac arrest one month later.
Favorable neurological outcomes were associated with a shorter collapse-to-resuscitation time. Additionally, the likelihood of a better outcome decreased for every minute that the patient's heart was not pumping blood.
The researchers calculated that CPR attempts on a person who has suffered from cardiac arrest should last for at least 38.5 minutes to help bring about a better neurological outcome.
The lead researcher, Dr. Nagao, also concluded that CPR may still be appropriate if the person's heartbeat returns.
According to American Heart Association (AHA) guidelines for CPR, published in 2010, bystanders should perform CPR until an emergency crew arrives.
This study was presented during the AHA Scientific Sessions on November 16.
The authors of the study did not disclose any conflicts of interest or publish funding information.