Transthoracic impedance variability to assess quality of chest compression in out-of-hospital cardiac arrest.

Background: Chest compression is a lifesaving intervention in out-of-hospital cardiac arrest (OHCA), but the optimal metrics to assess its quality have yet to be identified. The objective of this study was to investigate whether a new parameter, that is, the variability of the chest compression-generated transthoracic impedance (TTI), namely Imp , which measures the consistency of the chest compression maneuver, relates to resuscitation outcome.

Methods: This multicenter observational, retrospective study included OHCAs with shockable rhythm.