Updated guidelines revise recommended CPR rates, compression depth

The American Heart Association updated recommendations for cardiopulmonary resuscitation (CPR) and emergency cardiovascular care in a report geared toward inpatient and outpatient clinicians, as well as laypeople and emergency dispatchers.

The 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care incorporated evidence from systematic reviews to update the 2010 recommendations. The 14-part guideline appeared in Circulation. An executive summary is available.

Important changes in this update include upper limits of recommended compression rate and compression depth. For resuscitation of adults with cardiac arrest, the new guidelines recommend the following:

• Rescuers should perform chest compressions at a rate of 100 to 120 per minute (Class IIa, level of evidence [LOE] C-LD [limited data]). Adding an upper limit of compression rate stems from 1 large registry study that found an association between extremely rapid compression rates and inadequate compression depth.
• Rescuers should perform chest compressions at a depth of at least 2 inches or 5 cm for an average adult, while avoiding excessive chest compression depths greater than 2.4 inches or 6 cm (Class I, LOE C-LD). This was based on 1 publication that suggested potential harm from excessive chest compression depth.
• Total preshock and postshock pauses in chest compressions should be as short as possible (Class I, LOE C-LD) because shorter pauses can be associated with greater shock success, greater return of spontaneous circulation, and, in some studies, higher rates of survival to hospital discharge.
• With an unprotected airway, rescuers can try to achieve a chest compression fraction (defined as the time of chest compressions divided by the total time interval that CPR is provided) as high as possible, with a target of at least 60% (Class IIb, LOE C-LD). This addition is intended to limit interruptions in compressions and to maximize coronary perfusion and blood flow during CPR.
• Chest compressions and ventilation can be done in all patients in cardiac arrest, from either a cardiac or a noncardiac cause (Class IIb, LOE C-LD). When the victim has an advanced airway in place during CPR, rescuers do not need to deliver cycles of 30 compressions and 2 breaths, that is, interrupt compressions to deliver 2 breaths. Instead, rescuers can deliver 1 breath every 6 seconds (10 breaths per minute) while performing continuous chest compressions (Class IIb, LOE C-LD). This simple rate, rather than a range of breaths per minute, should be easier to learn, remember, and perform, the guideline said.

“Survival from both [in-hospital cardiac arrest] and [out-of-hospital cardiac arrest] has increased over the past decade, but there is still tremendous potential for improvement,” the authors concluded. “It is clear that successful resuscitation depends on coordinated systems of care that start with prompt rescuer actions, require delivery of high-quality CPR, and continue through optimized ACLS [advanced cardiovascular life support] and post-cardiac arrest care.”