If a person collapses with cardiac arrest in an out-of-hospital setting, lay bystanders who come to assist are more likely to help the patient by performing just chest compressions rather than conventional CPR (cardiopulmonary resuscitation) or no CPR, researchers write in JAMA (Journal of the American Medical Association). Conventional CPR includes giving mouth-to-mouth resuscitation.
The authors explain that cardiac arrest that occurs outside a hospital setting is a major public health concern, affecting about 300,000 people each year in the USA. Bystanders who come to the aid of the patient can help influence their outcomes.
A statewide program was set up in Arizona aimed at improving the survival rates for people with cardiac arrest outside a hospital setting.
The authors wrote:
These efforts included changes in the approach to the care provided by both bystanders and emergency medical services (EMS) personnel and were based on the increasing evidence in favor of minimizing interruptions in chest compressions during CPR.
As compression only CPR, known medically as COCPR is easier to teach and then perform by lay people compared to conventional CPR with mouth-to-mouth breathing, a multifaceted effort was launched to encourage COCPR.
Bentley J. Bobrow, M.D., who works at the Arizona Department of Health Services, Phoenix, and team carried out a study to find out whether COCPR would result in better outcomes for cardiac arrest patients outside a hospital setting than conventional CPR or no CPR. They also aimed to determine whether bystanders were more likely to come and help if they were taught COCPR.
Between January 2005 and December 2009, 4,415 individuals aged 18+ years were registered with out-of-hospital cardiac arrest. 2,900 of them received no CPR assistance from bystanders, 15.1% (666) received conventional CPR, and 19.2% (849) received COCPR.
The investigators report the following rates of survival to hospital discharge:
5.2% for those who received no CPR help of any kind from bystanders
7.8% for those who received conventional CPR from bystanders
13.3% for those who received COCPR from bystanders
In 2005, only 28.2% of people with cardiac arrest outside a hospital setting received any type of CPR from lay bystanders, compared to 39.9% in 2009.
The authors wrote:
Among patients who received bystander CPR, the proportion with COCPR increased significantly over time, from 19.6 percent in 2005 to 75.9 percent in 2009. Overall survival also increased significantly over time: from 3.7 percent in 2005 to 9.8 percent in 2009.
The investigators discovered, after further examination, that those receiving COCPR had a 60% higher chance of surviving compared to individuals receiving conventional CPR or no type of CPR from lay bystanders.
There may be several reasons why COCPR provides better outcomes than conventional CPR:
Even brief interruptions of chest compression can increase the likelihood of a serious drop of forward blood flow
The long ramp-up time to return to proper blood flow after resuming chest compressions
Conventional is more complicated to perform compared to chest only compressions
Performing the breaths (mouth-to-mouth) can take up a lot of time
During a cardiac arrest, adequate cerebral and coronary circulation is vital
In an accompanying editorial, David C. Cone, M.D., of the Yale University School of Medicine, New Haven, Conn., writes:
In the meantime, physicians and other health care professionals involved in resuscitation should look to the new [CPR] Guidelines 2010 documents for the international consensus on the science of compression-only CPR, and should look to new-curriculum CPR classes that will follow as opportunities to encourage the general public to learn this simple and potentially lifesaving skill.
"Chest Compression-Only CPR by Lay Rescuers and Survival From Out-of-Hospital Cardiac Arrest"
Bentley J. Bobrow, MD; Daniel W. Spaite, MD; Robert A. Berg, MD; Uwe Stolz, PhD, MPH; Arthur B. Sanders, MD; Karl B. Kern, MD; Tyler F. Vadeboncoeur, MD; Lani L. Clark, BS; John V. Gallagher, MD; J. Stephan Stapczynski, MD; Frank LoVecchio, DO; Terry J. Mullins, MBA; Will O. Humble, MPH; Gordon A. Ewy, MD
JAMA. 2010;304(13):1447-1454. doi:10.1001/jama.2010.1392