More Support for Chest-Compression-Only Resuscitation for Out-of-Hospital Cardiac Arrest

Steve Stiles
December 18, 2007 — Two observational studies published online December 10, 2007 in Circulation concluded that the conventional method of cardiopulmonary resuscitation (CPR) that calls for mouth-to-mouth assisted ventilation is no more effective than a chest-compression-only approach [1,2]. The findings support a good deal of international research supporting use of the latter method, which is less complicated and may be more appealing to potential bystander rescuers.
In their retrospective analysis of almost 10,000 cases of bystander resuscitation for cardiac arrest in which one or the other method was used [1], Katarina Bohm (Karolinska Institute, South General Hospital Stockholm, Sweden) and colleagues saw no significant difference in the odds that the victim would survive to be hospitalized or in one-month survival.
The findings support the use of the "simpler version of CPR," which can be especially useful "in dispatcher-assisted CPR and in cases involving elderly bystanders, in which the simplest algorithm is probably also the best," the group writes.
They point to "two large, independent, prospective, randomized trials" comparing the two methods that are ongoing in the US, Finland, and Sweden. "We therefore suggest waiting for the results of these randomized trials before starting any new discussion to change guidelines."
In the longer-term prospective study of about 4900 cases of witnessed out-of-hospital arrests by Dr Taku Iwami (National Cardiovascular Center, Suita, Japan) and associates [2], the chances of one-year survival with "favorable" neurologic outcomes was similarly increased with either method, compared with no bystander resuscitation — by 72% using the compression-only or "cardiac-only" technique, and by 57% with standard CPR.
"If cardiac-only resuscitation is simply as effective as conventional CPR, is there any reason to change lay CPR programs to focus on cardiac-only resuscitation? Perhaps," the group writes.
"Conventional CPR is a complex psychomotor task, and it typically is provided for <25% of out-of-hospital arrests," observe Iwami et al. "Specific educational campaigns to teach cardiac-only resuscitation may increase the rate of bystander CPR and improve the quality of cardiac-only resuscitation, thereby improving survival from out-of-hospital cardiac arrest.
Dr Gordon A Ewy (University of Arizona College of Medicine, Tucson), a longtime advocate of chest-compression-only resuscitation [3], who wasn't associated with either study, said that no randomized trial is needed for the technique to be recommended.
He pointed out to heartwire that the most current guidelines, published in 2005 [4], had updated the conventional-CPR recommended ratio from 15 chest compressions to two ventilations to 30 chest compressions to two ventilations. Whether 15 or 30 compressions, he said, the guidelines were based on consensus, not data.
But Ewy's group recently published data in a pig model suggesting that the continuous-compression technique, which he calls "cardiocerebral resuscitation," yields better outcomes than 30:2 CPR [5]. That, combined with the abundant supporting observational data, he said, showed that bystander CPR improves survival, and survival is better using the compression-only method.
"There's no question in my mind that the guidelines need to change, and they need to change now," Ewy said.
In Bohm et al's analysis of 8902 cases of out-of-hospital standard CPR and 1145 cases of compression-only resuscitation, 19.6% and 20% of patients, respectively, made it to the hospital alive; the adjusted odds ratio (OR) for CPR vs chest-compression-only was 1.03 (95% confidence interval [CI], 0.86 - 1.23). The one-month survival rates were 7.2% for standard CPR and 6.7% for the simpler technique (adjusted OR, 1.18 [95% CI, 0.89 - 1.56]).
In the prospective, population-based study of 4902 witnessed cardiac arrests in Japan, there were 783 cases in which bystanders performed conventional CPR and 544 in which only chest compressions were used; there were no bystander attempts in the remainder. Excluding arrests lasting >15 minutes, the one-year rate of survival with favorable neurologic outcomes was 4.1% for standard CPR, 2.5% for no resuscitation (OR 1.57 [95% CI, 0.95 - 2.60]), and 4.3% for compression only (OR 1.72 [95% CI, 1.01 - 2.95]).
Ewy, like Iwami et al, observes that regardless of inherent efficacy, the compression-only method is likely to save more lives than standard CPR, if only because it's more likely to be carried out. "People are afraid of getting an infection, or they just don't like doing mouth-to-mouth on a stranger, or they don't know how or are afraid they'll do harm. For whatever reason, it's being done in only one out of five cases in certain societies, and two out of five in others," according to Ewy. "And if you just call 911 and don't do anything until the paramedics get there, you might as well sign the patient's death certificate."
The Ministry of Education, Science, Sports, and Culture, Japan, and the Ministry of Health, Labor, and Welfare, Japan, supported the study by Iwami and colleagues. The study authors have disclosed no relevant financial relationships.
Sources
Bohm K, Rosenqvist M, Herlitz J, et al. Survival is similar after standard treatment and chest compression only in out-of-hospital bystander cardiopulmonary resuscitation. Circulation. Published online before print December 10, 2007.
Iwami T, Kawamura T, Hiraide A, et al. Effectiveness of bystander-initiated cardiac-only resuscitation for patients with out-of-hospital cardiac arrest. Circulation. Published online before print December 10, 2007.
Be a lifesaver with continuous chest compression CPR tutorial. University of Arizona Sarver Heart Center. Available at http://www.heart.arizona.edu/publiced/lifesaver.htm.
ECC Committee, Subcommittees and Task Forces of the American Heart Association. 2005 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation 2005; 112:IV1-IV203.
Ewy GA, Zuercher M, Hilwig RW, et al. Improved neurological outcome with continuous chest compressions compared with 30:2 compressions-to-ventilations cardiopulmonary