Chest Compression Alone Does the Job for Bystander CPR
Key Points:
Rescue breathing does not improve survival when added to chest compression for bystander CPR
Findings do not apply to health care professionals or bystanders who do not need dispatcher assistance
By Jason Kahn
Monday, August 02, 2010
Rescue breathing does nothing to improve survival when added to chest compressions for patients receiving bystander cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrest, according to 2 randomized trials published in the July 29, 2010, issue of the New England Journal of Medicine.
In the first study, researchers led by Thomas D. Rea, MD, of the University of Washington (Seattle, WA), assessed outcomes of dispatcher-assisted bystander CPR among 1,941 patients from EMS systems in Washington State and London, United Kingdom. Subjects were randomized to chest compression with or without rescue breathing.
There were no differences between the 2 groups in the rates of survival to hospital discharge (the primary endpoint) or having a pulse at the end of EMS care.
In addition, similar proportions of patients survived to discharge with a favorable neurologic status (14.4% for chest compression alone vs. 11.5% for chest compression plus breathing; P = 0.13) at sites that assessed the endpoint.
Interestingly, in subset analyses, some patient groups showed a trend toward improved survival to hospital discharge with chest compression alone, such as those with a cardiac cause of their arrests (15.5% vs. 12.3% for chest compression plus breathing; P = 0.09) and patients with shockable rhythms (31.9% vs. 25.7% for chest compression plus breathing; P = 0.09).
The researchers stressed that the results do not apply to CPR given by health care professionals. Nor do they apply to bystanders “who have been previously trained, are able to identify a cardiac arrest, and can provide CPR without dispatcher assistance,” they say. “Nonetheless, CPR performed by lay responders trained in compression plus rescue breathing often falls short of the guideline standards during an actual cardiac arrest.”
As such, the investigators conclude, “the results . . . strengthen a layperson CPR strategy that emphasizes chest compression and minimizes the role of rescue breathing.”
In the second trial, researchers led by Leif Svensson, MD, PhD, of the Stockholm Prehospital Center (Stockholm, Sweden), randomized 1,276 out-of-hospital cardiac arrest patients to dispatcher-assisted bystander CPR utilizing chest compressions with or without resuscitative breathing.
Thirty-day survival (the primary endpoint) was equivalent between the 2 groups, as was 1-day survival and survival to hospital discharge, although there was a slight numerical trend favoring the compression-only group for the latter 2 endpoints.
The 30-day survival and 1-day survival comparisons did not differ significantly upon further analyses in numerous subgroups based on age, sex, location of cardiac arrest, interval between call and first EMS response, and first cardiac rhythm.
While making clear that the results do “not apply to cardiac arrest caused by trauma, respiratory failure, or intoxication or to children under the age of 8 years or patients in whom bystanders perform CPR without instructions from dispatchers,” Dr. Svensson and colleagues conclude that “this study lends further support to the hypothesis that compression-only CPR, which is easier to learn and to perform, should be considered the preferred method for CPR performed by bystanders in patients with cardiac arrest.”
Rescue Breathing Still Important
In an editorial accompanying the papers, Myron L. Weisfeldt, MD, of the Johns Hopkins University School of Medicine (Baltimore, MD), notes that the message of the 2 studies is just as straightforward as their results: “[A]dvocating continuous chest compression without ventilation by a bystander should increase the frequency of bystanders’ effectively performing CPR and therefore increase the chances of survival after cardiac arrest.”
But CPR courses should still continue to teach rescue breathing, Dr. Weisfeldt writes, since most cases of cardiac arrest in children are due to obvious respiratory failure. In addition, he notes that not providing rescue breathing in adult patients whose arrests are due to noncardiac causes may even be detrimental.
Randomized studies are still required to investigate these and other issues, including the need for rescue breathing after a prolonged period of CPR and whether the benefits of compression-only CPR are evident primarily in cardiac arrest with initial ventricular tachycardia or fibrillation rather than arrest arising from other rhythms.
According to Dr. Weisfeldt, “The answers to these questions may be paradigm-shifting and will almost certainly be lifesaving.”