Continuous Compression Resuscitation

^{Introduction:}

Bystander cardiopulmonary resuscitation (CPR) is one of the major elements in the "chain of survival" for the treatment of patients in cardiac arrest. Recent reports have indicated a decrease in the number of laypersons performing CPR. One reason postulated for this decline in bystander CPR is lay rescuer reluctance to administer mouth-to-mouth breathing. The American Heart Association has called for simplification as a central educational theme in efforts to encourage more bystander participation. One dramatic step toward simplification is to eliminate mouth-to-mouth ventilation for lay rescuers. Although some continue to voice concern about this approach, others have begun to test such a strategy in preclinical cardiac arrest models and have found equivalent outcomes when standard airway (A), breathing (B), and compression (C) CPR is compared with continuous chest compression (CCC) CPR. These trials have all performed ABC CPR specifically as directed in the American Heart Association guidelines using a 3- to 4-second period for delivery of the 2 ventilations. Two clinical trials have also shown the benefit of CCC CPR.

A recent report from the United Kingdom in which 495 laypersons were prospectively randomized to training in either standard ABC CPR or CCC CPR demonstrated that extensive interruptions occur when laypersons stop chest compressions to ventilate. The average time from stopping compressions to restarting compressions for the delivery of 2 mouth-to-mouth ventilations was 16 seconds. Circulation was interrupted for this period, resulting in no circulatory support during nearly 60% of the resuscitation time. The purpose of the present study was to compare outcome results for single-rescuer standard ABC CPR, with clinically realistic compression interruptions for ventilation, versus CCC CPR.

Background— Interruptions to chest compression–generated blood flow during cardiopulmonary resuscitation (CPR) are detrimental. Data show that such interruptions for mouth-to-mouth ventilation require a period of "rebuilding" of coronary perfusion pressure to obtain the level achieved before the interruption. Whether such hemodynamic compromise from pausing to ventilate is enough to affect outcome is unknown.

Methods and Results— Thirty swine (weight 35±2 kg) underwent 3 minutes of untreated ventricular fibrillation before 12 minutes of basic life support CPR. Animals were randomized to receive either standard airway (A), breathing (B), and compression (C) CPR with expired-gas ventilation in a 15:2 compression-to-ventilation ratio or continuous chest compression CPR. Those randomized to the standard 15:2 group had no chest compressions for a period of 16 seconds each time the 2 ventilations were delivered. Defibrillation was attempted at 15 minutes of cardiac arrest. All resuscitated animals were supported in an intensive care environment for 1 hour, then in a maintenance facility for 24 hours. The primary end point of neurologically normal 24-hour survival was significantly better in the experimental group receiving continuous chest compression CPR (12 of 15 versus 2 of 15; P<0.0001).

Conclusions— Mouth-to-mouth ventilation performed by single layperson rescuers produces substantial interruptions in chest compression–supported circulation. Continuous chest compression CPR produces greater neurologically normal 24-hour survival than standard ABC CPR when performed in a clinically realistic fashion. Any technique that minimizes lengthy interruptions of chest compressions during the first 10 to 15 minutes of basic life support should be given serious consideration in future efforts to improve outcome results from cardiac arrest.

^{(Circulation. 2002;105:645.)
© 2002 American Heart Association, Inc.}