Active compression-decompression resuscitation and impedance threshold device for out-of-hospital cardiac arrest: a systematic review and metaanalysis of randomized controlled trials.

Active compression-decompression resuscitation and impedance threshold device are proposed to improve survival of patients of cardiac arrest by lowering intrathoracic pressure and increasing cardiac output. The results of clinical studies of active compression-decompression resuscitation or impedance threshold device were controversial. This metaanalysis pooled results of randomized controlled trials to examine whether active compression-decompression resuscitation or impedance threshold device would improve outcomes of out-of-hospital cardiac arrest in comparison with standard cardiopulmonary resuscitation and to explore factors modifying these effects.