"Push Hard and Push Fast," Say New CPR Guidelines

Dramatic changes to cardiopulmonary resuscitation (CPR) and emphasis on chest compressions highlight the 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care published online in November (Circulation: Journal of the American Heart Association). The AHA guidelines provide recommendations for how lay rescuers and emergency healthcare providers should resuscitate victims of cardiovascular emergencies.

For laypeople performing "bystander" CPR, the critical change from previous guidelines is to double the number of chest compressions for every two mouth-to-mouth "rescue breaths." Now, the AHA says, 30 chest compressions should be given for every two rescue breaths. Topics in the guidelines also include the use of automated external defibrillators (AEDs) and recommendations for advanced cardiovascular life support (ACLS) and pediatric advanced life support (PALS).

"Many of these new guidelines are based on research done by our team here in Milwaukee," said Tom P. Aufderheide, MD, FACEP, Medical College of Wisconsin Professor of Emergency Medicine. "The guidelines recognize that maximizing chest compressions and reducing the frequency of ventilations improves hemodynamics during CPR and that the quality of CPR delivered at the scene of cardiac arrest really matters." The Medical College resuscitation research team headed by Dr. Aufderheide is a national leader in the field, which has generated about $11 million in National Institutes of Health funding. Dr. Aufderheide practices at the Froedtert & The Medical College of Wisconsin Emergency Department & Trauma Center.

"There are many reasons the new guidelines call for more chest compressions," said Dr. Aufderheide. "First is that we have learned over the past five years that there are hemodynamically significant components of CPR that contribute to good blood flow while CPR is being performed. Probably the greatest detriment to superb forward blood flow is not performing chest compressions.

"Studies have been done in professional EMS systems and in hospitals demonstrating that in up to half of resuscitation time there is no chest compression being performed. Professional rescuers don't provide chest compressions when they, for example, put in an advanced airway, when they check for pulses, when they assess the patient for response to interventions, while they're preparing to do defibrillation, while they're assessing response to defibrillation. When you add all of that up, half of the time chest compressions are not being performed."

Ventilation Also Very Important
For CPR in particular, the new guidelines greatly simplify the approach to bystander resuscitation as part of a national AHA effort to improve outcomes as well as double the number of lay rescuers trained in CPR in the next five years. For example, the guidelines apply the same standards for CPR performed on adults, children and infants (except newborns) and recommend that lay rescuers not stop chest compressions periodically to check for improvement.

"It is unreasonable to expect a successful outcome when half of the time of resuscitation is spent not performing chest compressions," said Dr. Aufderheide. "So, the doubling of chest compression to ventilation ratio is an attempt to maximize chest compression time. The other aspect to the ratio is ventilations. That data has come out of the research done by our group here. It shows that excessive ventilation rates increase pressure within the chest and that pressure inhibits venous blood return back into the chest, decreasing forward blood flow, decreasing hemodynamics and decreasing survival from cardiac arrest.

"In my judgment, that is close to being as important as lack of chest compressions. So the 30 to 2 compression to ventilation ratio really has two components, compression and ventilation, and it really advances us closer to solving both of those problems. However, the hemodynamic compromise that occurs from excessive ventilation rates has only been studied in professional rescuers, not in laypeople. By doing mouth-to-mouth, you really can't ventilate so fast that it would probably reduce hemodynamics.

"We found in our (emergency medical) system here in Milwaukee, for example, that professional rescuers were ventilating up to fifty times a minute. With that excessive ventilation rate the pressures within the chest are very high and significantly compromise hemodynamics. It would be almost impossible for a lay rescuer to ventilate that frequently."

Bystander CPR has been shown to double or triple survival rates in cardiac arrest, Dr. Aufderheide noted. The "push hard and push fast" theme echoed by the authors when the new guidelines were released may help to save even more lives in the future. "We're hoping that that the new guidelines will make CPR easier to learn, easier to remember, and improve the confidence that laypeople will have in responding and acting during an emergency," said Dr. Aufderheide. "The CPR initiative by the national AHA is focused on increasing the rate of bystander CPR. Right now, about nine million people take AHA CPR courses; we are intending to at least double that by the year 2010."

Family and Friends: 20-Minute Home CPR Course
Another new development in CPR training is a course that takes only about 20 minutes to complete and can be taken at home or in schools without an experienced emergency response trainer present. "We have just completed our first home CPR course, called CPR Any Time for Family and Friends," said Dr. Aufderheide. "This was a project that I and many other members of the national AHA have been working on for many years.

"It is a kit that contains a small inflatable mannequin and a training DVD. It's inexpensive ($29). We tested this training program and published results comparing how well completely untrained laypeople performed CPR after this twenty-minute course versus a four-hour AHA CPR course. We found that the quality of CPR with the twenty-minute course was equivalent if not better in many respects than with the four-hour course."

CPR Any Time for Family and Friends is now available from local AHA chapters. "We're very excited about this new educational product," said Dr. Aufderheide. "In many respects it's the model for all future AHA CPR training programs. It's important to understand that the home training course does not provide certification and that it really targets individuals who would not go to an AHA training course, perhaps because they don't have the time to take off of work for half a day.

"They can instead, in twenty minutes and in the privacy of their own home, learn the skill, and learn the skill as well as they would from a four-hour course, when it's convenient for them. This course will also be very useful in school settings, where the four-hour course may take a teacher several days to complete because many other subjects compete for class time. This can be done in 20 minutes, so teachers in a school can teach an entire class CPR in half an hour."

AED use in the home will be included in the next "short course" being developed by Dr. Aufderheide and other AHA members. "We're hoping that this all really opens a lot of doors to increased bystander CPR, increasing the number of people who learn CPR skills and AED use, as well as the potential opportunity for dissemination of CPR courses in the schools," said Dr. Aufderheide.

For laypeople already trained in CPR, Dr. Aufderheide recommends a refresher course every two years regardless of changes in the AHA guidelines. "What I would tell people right now is to take a refresher course as soon as it's convenient," he said. "If they experience an emergency before that, act. Intervene. The old guidelines can also save a life, so don't let the new guidelines stop you from helping others. What we really want to promote is giving people the skills to be confident enough to act in an emergency, get involved, and possibly save a life."

Dan Ullrich
HealthLink Contributing Writer

Some information for this article provided by the American Heart Association. For a CPR Any Time for Family and Friends training kit and other training and educational opportunities, contact your local Heart Association chapter.

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.