Cardiac arrest is the sudden loss of heart function, typically resulting from an abnormal heart rhythm that causes the heart to quiver erratically and stop pumping blood. According to the American Heart Association, effective bystander CPR provided immediately after sudden cardiac arrest can double or triple a victim's chance of survival.
In a review of 547,218 cardiac arrests occurring in 2005-2009, researchers identified almost 140,000 incidents witnessed by bystanders without a physician's involvement. Bystander groups studied included family members, friends and colleagues, passers-by and others.
- The time interval between collapse and emergency call and between call and arrival to patients was shortest when witnessed by passers-by.
- Family members were least likely (36.5 percent) to administer CPR, but most likely to receive telephone instructions from dispatchers (45.8 percent).
- The telephone instruction to family members most frequently failed (39.4 percent) and family members most often used chest compressions only (67.9 percent).
"If you go into cardiac arrest in front of your family, you may not survive," said medical doctor Hideo Inaba, professor and chairman of the Department of Emergency Medical Science at Kanazawa University Graduate School of Medicine in Kanazawa, Japan. "Different strategies, including basic life support instruction targeting smaller households, especially those with elderly residents, would improve survival, as would recruiting well-trained citizens willing to perform CPR on victims whose arrest was witnessed by family members."
CPR provided by family members may have been ineffective due to their lack of knowledge or fear of injuring their loved one, said Inaba. Cultural and demographic issues in Japan, which has a large gender gap, may also have contributed to the findings, he said.
In a study conducted in 2008, researchers found that Japanese women were less likely to attempt CPR. Men accounted for a majority of cardiac arrests in the current study, and their wives or daughters-in-law witnessed most of them, researchers said.
Japan has a rapidly aging population, with elderly people, mostly couples, in 42 percent of households in 2010, Inaba said. "These characteristics of Japanese households might have contributed to our observations and may be different from households in the United States," Inaba said. "Also, the percentage of older persons in Japan is larger than in the U.S. population. So the results may be less applicable." Furthermore, the database didn't include the exact location of each cardiac arrest, although basic life support response and outcomes differ between locations. The type of bystander who responds is also closely related to the location of the cardiac arrest.
MEDICA.de; Quelle: American Heart Association