Hands-Only (Compression-Only) Cardiopulmonary Resuscitation: A Call to Action for Bystander Response to Adults Who Experience Out-of-Hospital Sudden Cardiac Arrest

Bystanders who witness the sudden collapse of an adult should activate the emergency medical services (EMS) system and provide high-quality chest compressions by pushing hard and fast in the middle of the victim’s chest, with minimal interruptions. This recommendation is based on evaluation of recent scientific studies and consensus of the American Heart Association Emergency Cardiovascular Care (ECC) Committee. This science advisory is published to amend and clarify the “2005 American Heart Association (AHA) Guidelines for Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care (ECC)” for bystanders who witness an adult out-of-hospital sudden cardiac arrest. Ten years ago, the AHA commissioned a working group of resuscitation scientists to reappraise the Association’s inclusion of ventilations in the recommended sequence for bystander cardiopulmonary resuscitation (CPR). The working group evaluated peer-reviewed reports of laboratory and human research and summarized their findings in a 1997 statement.1 The key conclusion of that statement was that “Current guidelines for performing mouth-to-mouth ventilation during CPR should not be changed at this time.”1 In the animal studies cited in the 1997 statement, when ventricular fibrillation arrest was of short (under 6 minutes) duration, the addition of rescue ventilations to chest compressions did not improve outcome compared with chest compressions alone (LOE 6*).2–8 Analysis of human data from a national out-of-hospital CPR registry documented no survival advantage to ventilations plus compressions compared with the provision of chest compressions alone during bystander resuscitation (LOE 4*).9,10 Although these studies were not deemed sufficient to justify the elimination of ventilations from the bystander CPR sequence, the 1997 statement strongly encouraged further research that would focus on “...the timing, rate, and depth [of ventilations] as well as conditions under which respiratory assistance should be used.” The statement also recommended “...more research on real-world obstacles to learning, remembering, and actually performing CPR...” In addition, the statement contained a secondary conclusion that “...provision of chest compression without mouth-to-mouth ventilation is far better than not attempting resuscitation at all.”1 The AHA’s recent Guidelines for CPR and ECC have reflected the primary and secondary conclusions of the 1997 statement: “Laypersons should be encouraged to do compression-only CPR if they are unable or unwilling to provide rescue breaths (Class IIa), although the best method of CPR is compressions coordinated with ventilations.”11,12 In addition, the Guidelines have recommended compressiononly CPR for dispatcher-assisted instructions for untrained bystanders.“11,12 The “2005 AHA Guidelines for CPR and ECC” noted the need to increase the prevalence and quality of bystander CPR. The Guidelines and training materials emphasized the importance of the delivery of high-quality chest compressions, that is, compressions of adequate rate and depth with full-chest recoil and minimal interruptions.12 To limit the frequency of