CPR and rapid defibrillation is best for cardiac arrest outside of a hospital

Research published in the New England Journal of Medicine suggests that pre-hospital advanced life support training does not increase the survival rate for people who experience a cardiac arrest outside of a hospital. On the other hand, bystander CardioPulmonary Resuscitation and rapid defibrillation programs are crucial interventions that can significantly impact survival rates.

CardioPulmonary Resuscitation is a technique for reviving people whose hearts have stopped beating. Also a class that teaches the technique along with others needed to maintain someone's breathing and blood flow.

Defibrillation is the process of passing a DC electrical current through heart muscle fibers that have an electrical imbalance and are quivering instead of contracting in unison. If the current depolarizes the fibers uniformly, it will result in an organized rhythm.

The studies lead author, Dr. Ian Stiell, is an emergency room physician, researcher and teacher affiliated with The Ottawa Hospital, the Ottawa Health Research Institute and the University of Ottawa. Sudden death due to cardiac arrest accounts for approximately half a million American lives each year, with almost one in two occurring outside of a hospital. The issue is equally as serious in Canada.

In the hopes of increasing survival chances and quality of life, Ontario introduced ALS training several years ago. This additional training gives paramedics the ability to perform advance procedures at the scene of a cardiac arrest, including airway management (intubation) and the administration of intravenous drug therapy. ALS is one part of a comprehensive approach to strengthening community response to cardiac arrest and improving survival rates. Other parts of the approach include CPR training for police officers, firefighters, and the general public, as well as the installation of automatic defibrillators (computer-assisted devices that give electric shock to the heart) in public places so that they can be close at hand when a cardiac arrest occurs.

Before committing funds to expand ALS training, however, the Ministry of Health and Long-Term Care required further research to demonstrate the effectiveness of the program. The Ontario Pre-hospital Advanced Life Support (OPALS) study was created to determine the impact of ALS training in comparison with other interventions on survival rates for cardiac arrests that take place in non-hospital settings. An Ottawa-based research team led by Dr. Stiell studied over 10,000 patients over ten years across 17 urban centres in Ontario to determine the added benefit of ALS programs.

Researchers concluded that the best chance of surviving a cardiac arrest is if someone actually witnesses the event and intervenes immediately. The study also showed that cardiac arrest survival improved significantly if a citizen or first responder (a police officer or firefighter, for example) performs CPR, and if rapid defibrillation is applied within 8 minutes. Researchers could not, however, demonstrate a change in survival rates associated with having ALS trained personnel attend to the cardiac arrest victim, mainly because immediate intervention is key.

Given these findings, the researchers raise concerns about the low rates of citizen-initiated CPR and suggest that investing more in training and awareness programs for the general public may have a greater impact on cardiac arrest survival rates than expanding the number of ALS-trained personnel at this time. "In order to save lives, health officials and planners must go back to the basics, and make citizen CPR training and the rapid availability of defibrillation priorities," said Dr. Stiell.

Future studies will examine the benefits of various interventions, including ALS, on patients with breathing difficulties and trauma patients. A recently awarded $ 4 million (CDN) grant from the U.S. National Institutes of Health will ensure that Dr. Stiell's Ottawa-based research group can continue to shape the future planning of pre-hospital emergency medical services.

Dr. Stiell is an emergency physician at The Ottawa Hospital, a Chair of Emergency Medicine Research at the Ottawa Health Research Institute, and Head of Department of Emergency Medicine at University of Ottawa. The author of the world-renowned Ottawa ankle and knee rules, a clinical decision aid, Dr. Stiell holds the titles of Distinguished Investigator with the Canadian Institutes of Health Research, and is a rare Canadian member of Institute of Medicine with the U.S. National Academy of Sciences.