It is important to revisit and challenge dogma in medicine. When you think of defibrillation you hear the word "CLEAR" and know your primary job in that one instant is to make sure that none of the medical professionals participating in that code situation are at risk of receiving a life threatening shock. However, with the advent of gel adhesive pads is it still dangerous?
When clearing the patient for defibrillation, this causes an interruption in chest compressions causing the central perfusion pressure (CPP) to drop, and it can take more than one minute of good-quality chest compressions to restore them to pre-pause levels. CPP has been found to be the best single predictor of ROSC, with values less than 15mmHg predicting a failure. Therefore, we are greatly increasing the morbidity and mortality of our patients with each second off the chest. Circulation published the article "Hands-On Defibrillation, An Analysis of Electrical Current Flow Through Rescuers in Direct Contact with Patients During Biphasic External Defibrillation," in which they investigate the amount of leakage voltage and current to a rescuer receives during defibrillation. They found that the current measured in the rescuer’s body ranged from 19 to 907µA. In most cases, the leakage current measured below recommended safety standards and none of the rescuers felt a shock.
The emergence of pregelled self-adhesive pads has greatly decreased the risk of current transmission due to contained gel, reliable pad placement, and decreased operator error. Risk is heightened if the rescuer is in contact with a highly conductive material such as fluids including sweat, gel, or other bodily fluids; however, this can be minimized by placing a dry towel or blanket between the patient and rescuer. Also, the investigators in the study wore gloves, which provide insulation against electrical current.
Hands-off defibrillation should still be practiced if hand-held paddle electrodes are being used or if there is a highly conductive substance between the provider and patient. More research needs to be done but it is on the horizon and could alter the way we do CPR in the future. The phrase "I'm clear, you're clear, we are all clear" may soon be a memory.
American Academy of Emergency Medicine. 2013;4(4) © 2013 American Academy of Emergency Medicine