Background

The quality of cardiopulmonary resuscitation (CPR) is associated with the probability of survival in people experiencing sudden cardiac arrest.1 Features of CPR quality associated with clinical outcomes include compression rate, compression depth and compression fraction (the proportion of time during a resuscitation attempt when chest compressions are being provided). Evidence suggests that chest compression quality can suffer because of suboptimal team leadership, provider fatigue or distraction with other resuscitation activities (eg, airway management, patient transfer, pulse checks).1

Mechanical chest compression devices have been developed to provide more consistent high quality chest compressions. Devices available on the market today use one of two fundamental mechanisms to facilitate chest compression. Some employ a piston mechanism positioned over the sternum. The LUCAS device, which employs a piston, also includes a suction cup interface with the chest wall to allow active decompression during the recoil phase of the duty cycle. Other devices, namely the ZOLL Autopulse, use a load-distributing band which encircles the chest of the patient. Activation of the device causes a rhythmic shortening and lengthening of the band to compress the chest circumferentially.

Early evidence, including animal studies and observational studies in humans suggested that mechanical chest compression devices might be superior to conventional manual chest compressions during cardiac arrest.2 However, there has always been a concern that the devices may cause injury (eg, internal organ trauma) or may introduce dangerous interruptions in chest compressions while they are being deployed during resuscitation attempts. Several clinical trials have been published to explore the effectiveness of mechanical chest compression devices compared with standard manual compressions during cardiac arrest. Our Cochrane systematic review sought to evaluate these clinical trials and determine the relative effectiveness of these two strategies for cardiac arrest.2