Background: Recently, it has been demonstrated that rescuers could safely provide a low, static downward force in direct contact with patients during elective cardioversion. The purpose of our experimental study was to investigate whether shock delivery during uninterrupted chest compressions may have an impact on cardiopulmonary resuscitation (CPR) quality and can be safely performed in a realistic animal model of CPR.
Methods and results: Twenty anesthetized swine were subjected to 7 minutes of ventricular fibrillation followed by CPR according to the 2010 American Heart Association Guidelines. Pregelled self-adhesive defibrillation electrodes were attached onto the torso in the ventrodorsal direction and connected to a biphasic defibrillator. Animals were randomized either to (1) hands-on defibrillation, where rescuers wore 2 pairs of polyethylene gloves and shocks were delivered during ongoing chest compressions, or (2) hands-off defibrillation, where hands were taken off during defibrillation. CPR was successful in 9 out of 10 animals in the hands-on group (versus 8 out of 10 animals in the hands-off group; not significant). In the hands-on group, chest compressions were interrupted for 0.8% [0.6%; 1.4%] of the total CPR time (versus 8.2% [4.2%; 9.0%]; P=0.0003), and coronary perfusion pressure was earlier restored to its pre-interruption level (P=0.0205). Also, rescuers neither sensed any kind of electric stimulus nor did Holter ECG reveal any serious cardiac arrhythmia.
Conclusions: Hands-on defibrillation may improve CPR quality and could be safely performed during uninterrupted chest compressions in our standardized porcine model.
Keywords: cardiac arrest; cardiopulmonary resuscitation; chest compression; defibrillation; resuscitation.